The article will tell you how the ODC system works in PI pipes and how to do it correctly. The information is useful for those who want to save money and carry out the installation themselves, and for those who already have experience using such a heating network, but the remote control has failed or was performed poorly.

Ignorance of the basic principles of operation, incorrect installation of elements and inability to handle devices often lead to the fact that everything good is considered useless or of no use to anyone. This happened with the system for operational remote control of heating networks: the idea was great, but the implementation, as always, let us down. The indifference of the customer, on the one hand, and the “responsible” work of the builders, on the other, have led to the fact that in our country, SODK works correctly in at best 50% of constructed pipelines, and only 20% of organizations use it. Taking Europe as an example, even not far away, say Poland, you can see that the incorrect operation of the remote control system is equivalent to a pipeline accident with immediate repair work. In our country, it is much more common to see a street dug up in the middle of winter in search of the location of a heating pipe break than to see a team of electricians carrying out preventive work in the summer. In order to make things clear, let’s consider the SODC in heating networks from the very beginning.

Purpose

Heating network pipelines remain steel from generation to generation, and the main reason for their destruction is corrosion. It occurs due to contact with moisture, and the outer wall of the metal pipe is more susceptible to rust. The main function of the SDS is to control the dryness of the pipeline insulation. Moreover, the reasons are indicated without distinction as the ingress of moisture from the outside due to a defect in the plastic pipe-shell, or the ingress of coolant onto the insulation as a result of a defect in the steel heat pipe.

Using a special tool and SODC you can determine:

• insulation getting wet;
• distance to wet insulation;
• direct contact of the SODK wire and the metal pipe;
• broken SODK wires;
• violation of the insulating layer of the connecting cable.

Principle of operation

The operation of the system is based on the property of water to increase the conductivity of electric current. Polyurethane foam used as insulation in PI pipes in a dry state has an enormous resistance, which electricians characterize as infinitely large. When moisture enters the foam, conductivity instantly improves, and devices connected to the system record a decrease in insulation resistance.

Areas of use

It makes sense to use pipelines equipped with an online remote monitoring system for any underground installation. Quite often, even knowing that the pipeline has a defect and there are significant losses of coolant, it is almost impossible to visually determine the location of the break. It is precisely because of this that winter period you have to either dig up the entire street in search of a leak, or wait until the water washes its way out. The second option quite often ends in news reports with notes that in the city of N, due to an accident on heating networks and a collapse of the surface of the earth, cars, people or anything else that had the misfortune of being nearby fell through.

The location of the pipeline in the channel does not add any information content. Due to steam, it is not always possible to determine the leak point and excavation will still be significant and long-lasting. The only exception, perhaps, is large passage tunnels with communications, but they are rarely built and are very expensive.

The option of aerial laying of pipelines is where the UEC system makes no practical sense. All leaks are visible to the naked eye and waste additional control to nothing.

Structure and structure

PI pipes used in heating networks consist of steel pipe, shell pipes made of polyethylene and polyurethane foam as insulation. This foam contains 3 copper conductors with a cross section of 1.5 mm 2 with a resistivity from 0.012 to 0.015 Ohm/m. The wires located in the upper part are assembled into a circuit, in the “10 minutes to 2 hours” position, the third remains unused. The signal or main conductor is considered to be the one located on the right in the direction of movement of the coolant. It enters all branches and it is by it that the condition of the pipes is determined. The left conductor is a transit conductor, its main function is to create a loop.

To extend cable outlets and connect pipelines to switching points, connecting cables are used. Usually 3 or 5 cores with the same cross-section of 1.5 mm.

The switching terminals themselves are located in carpet boxes installed on the street or in the premises of pumping and heating points.

Measurements are carried out using specialized instruments. Usually this is a portable pulse reflectometer of domestic production. For permanent installation There are also certain devices, but they are not very informative and in most cases are not used.

Installation

Assembly of all system elements occurs after welding of the pipeline. And if most of the work on the construction of a heating main is carried out exclusively by specialists and using equipment, then with a little knowledge in the field of electrical engineering and the presence of a soldering iron, a gas burner and a megohmmeter, you can do the work of installing remote control yourself. To perform it correctly, you should adhere to the following sequence:

• check the integrity of the conductors in the pipe insulation by ringing;
• remove foam to a depth of 2-3 cm, regardless of the degree of wetting;

• carefully unwind and straighten the conductors rolled up for transportation;
• install plastic stands on the pipe, secure them with tape;
• clean the conductors with sandpaper and degrease;
• tension the conductors within reasonable limits (excessive tension can cause the wire to break due to thermal expansion of the pipe, insufficient for the conductor to sag and contact with the pipe);
• connecting and soldering conductors to each other (do not confuse the signal and transit wires with each other);

• press the wires into special slots in the plastic supports;
• evaluate the strength of the connection with your hands;
• degrease with a solvent and dry the ends of the shell pipes using a gas burner for subsequent installation of the coupling;
• heating the prepared ends to a temperature of 60 degrees and installing glue;
• push the coupling onto the connection, having first removed the white protective film, shrink using a burner flame;
• drill 2 holes in the coupling to assess the tightness and subsequent foaming;
• assess the tightness: a pressure gauge is installed in one hole, air is supplied through the other, and the quality of the connection is assessed based on pressure retention;

• cut off the heat-shrinkable tape;
• heat the area at the coupling/pipe-shell junction and attach one end of the tape;
• lay the tape symmetrically over the joint and secure it with an overlap;
• heat the locking plate and close the joint of the tape with it;
• shrink the tape with a burner flame;
• carry out repeated air pressure testing as described above;
• mix foaming components A and B and pour through the hole into the cavity under the installed coupling;
• when moving the foam towards the hole, install a drain plug to remove air;
• after foaming is completed, clean the surface of the coupling from foam and install a weld-in plug;
• after assembling the system in the pipe part, extend the conductors at the output points;
• install carpet drawers;
• lay extended conductors in galvanized pipes from the outlet on the pipe to the installed carpet box;
• install and connect switching terminals in accordance with the project;

• connect stationary detectors;
• Perform a full check using a reflectometer.

The description discusses the option of using heat-shrinkable couplings; there is also another type of joint insulation - electric welded couplings. In this case, the process will be a little more complicated due to the use of electrical heating elements, but the essence remains the same.

When performing work on installing the UEC system, there are the most common mistakes. They rarely depend on who performed the work - the customer himself or the builder. The most important of them is loose installation of couplings. If there is no tightness, the system may become wet after the first rain. The second mistake is unselected foam at the joints: even if it looks visually absolutely dry, it often carries excess moisture and affects the correct operation of the system. After detecting a defect, you should observe the dynamics and decide when to make repairs: immediately or during the summer inter-heating period.

Repair methods

Repair of the UEC system is sometimes required already at the construction stage. Let's look at a few common cases.

1. The signal wire is broken at the insulation exit.

Foam should be removed before it forms required quantity conductor and increase the length by soldering an additional wire (you can use leftovers from other joints). When carrying out soldering, be careful not to allow the pipeline insulation to ignite.

1. The wire of the UEC system is in contact with the pipe.

If it is impossible to get to the point of contact without violating the integrity of the shell, you should use the 3rd unused wire to connect to the circuit instead of the defective conductor. If all conductors are unusable due to a manufacturing defect, the supplier must be notified. Depending on its capabilities and your desire, the pipe will be replaced or repaired with a reduction in cost right on the spot. If for any reason communication with the supplier is impossible, do-it-yourself repair carried out as follows:

• determining the point of contact;
• section of the shell pipe;
• foam sampling;
• eliminating contact, soldering the conductor if necessary;
• restoration of the insulation layer;
• restoring the integrity of the shell pipe using a repair coupling or extruder.

During the operation of heating networks, repairs are associated not so much with restoring functionality, but with drying the foam. The reasons can be very different: construction errors when sealing couplings, rupture of the heating pipe, careless excavation work near the pipes and much more. If exposed to moisture the best option is to remove it to normal resistance levels. This is achieved in various ways: from drying with the shell open to replacing the insulating layer. The degree of dryness is controlled using a pulse reflectometer. After achieving the required indicators, restoration of the integrity of the shell is carried out in the same way as described above.

Conclusion

Finally, I would like to express the hope that after reading the article, not only private owners who are building networks for their own will think about the need to use a control system production building or office, but also services closely involved in the operation of pipelines. Perhaps then there will be much fewer accidents and financial losses when centralized heating cities.

Olga Ustimkina, rmnt.ru

Purpose

The operational remote monitoring system (ORMS) is designed to carry out continuous monitoring of the condition of the thermal insulation layer of polyurethane foam (PUF) of pre-insulated pipelines throughout their entire service life. SODK is one of the main tools Maintenance pipelines built using “pipe-in-pipe” technology using signal copper conductors. The SODK complex of instruments and equipment makes it possible to locate damage locations in a timely manner and with great accuracy. The use of SODK contributes to safe operation pipeline systems, allows you to significantly reduce costs and time for repair work.

Operating principle and system organization

The control system is based on the use of an insulation moisture sensor distributed along the entire length of the pipeline. Signal copper conductors (at least two), located in the heat-insulating layer of each pipeline element, are connected along the entire length of the branched pipeline network into a two-wire line, combined at the end elements into a single loop. Conductors of any branches are included in the break of the signal conductor of the main pipeline. This loop of copper signal conductors, the steel pipe of all pipeline elements and the thermal insulation layer of rigid polyurethane foam between them form the insulation moisture sensor. The electrical and wave properties of this sensor allow:

1. Monitor the length of the humidification sensor or the length of the signal loop and, as a consequence, the length of the pipeline section covered by this sensor.

2. Monitor the humidity state of the heat-insulating layer of the pipeline section covered by this sensor.

3. Search for places where the heat-insulating layer is moistened or where the signal wire is broken in the section of the pipeline covered by this sensor.

Controlling the length of the humidification sensor is necessary to obtain reliable information about the state of humidity of the heat-insulating layer along the entire length of the pipeline section covered by this sensor. The length of the signal loop (the length of the humidification sensor) is determined as the ratio of the total resistance of the signal conductors connected in a closed circuit to their resistivity. The length of the pipeline section covered by this sensor is half.

When monitoring the humidity state, the principle of measuring the electrical conductivity of the heat-insulating layer is used. With increasing humidity, the electrical conductivity of thermal insulation increases and the insulation resistance decreases. An increase in the humidity of the thermal insulation layer can be caused by leakage of coolant from a steel pipeline or penetration of moisture through the outer shell of the pipeline.

The search for damage sites is carried out on the principle of pulse reflection (pulse reflectometry method). Moistening of the insulating layer or a wire break leads to a change in wave characteristics insulation moisture sensor in specific local areas. The essence of the reflected pulse method is to probe a line of signal conductors with high-frequency pulses. Determining the delay between the time of sending probing pulses and the time of receiving pulses reflected from inhomogeneities of wave impedances (wet insulation or damage to signal conductors) allows you to calculate the distances to these inhomogeneities.

For operational work with the insulation moisture sensor, the signal conductors and the “mass” of the steel pipe body are removed from the heat-insulating layer. These outputs are organized using special pipeline elements in which the signal conductors are output by a cable passing through the external insulation using a sealing device. These cables, led out into technological rooms, ground or wall carpets, together with the terminals connected to them, form control and switching points along the route - technological measuring points.

There are different end and intermediate measuring technological points.

Pipeline end elements with cable outlets are used at end measuring points. Cables from the supply and return pipes are connected to the end terminal installed in technological rooms or structures, ground or wall carpets.

At intermediate points, pipeline elements with an intermediate cable outlet are usually used. Cables from both pipelines are brought out into the ground carpet or technological structures and connected to an intermediate or double end terminal. But in places where the thermal insulation is broken (in a thermal chamber, etc.), the organization of an intermediate measuring point is carried out using end elements with cable leads. Cables from all pipeline elements are led out into the ground carpet or technological structure and connected to the appropriate terminal.

Technological measuring points installed at certain distances make it possible to quickly carry out exploratory measurements with sufficient accuracy.

Part of the equipment

The control system is divided into the following parts: pipe, signal and additional devices.

The pipe part is all the pipeline elements and components that directly form the insulation moisture sensor:

1. Pipe components with two or more copper signal conductors.
2. Intermediate and end cable terminals.
3. Pipeline end elements.
4. Installation and connection kits for connecting signal conductors when waterproofing joints and for extending cable outlets.

Pipeline elements with two or more copper signal conductors are pre-insulated pipes, bends, expansion joints, tees, Ball Valves, and so on.

Signal conductors installed inside the polyurethane foam insulation of each element are located parallel to the steel heat-carrying pipe at a distance of 16÷25 mm. from her. When assembling pipes, the conductors are fixed in polyethylene sheath centralizers, which are installed at a distance of 0.8÷1.2 m from each other. These conductors are made of copper wire with a cross section of 1.5 mm 2 (grade MM 1.5).

In all elements, the control system wires are located in the “ten minutes to two o’clock” position.

The end cable outlet is installed at the end of the thermal insulation. Structurally, it can be performed in two versions.

The first option is a pipeline end element with a cable outlet and a metal insulation plug (ZIM KV). In this element, two wires of a three-core cable are connected to the signal conductors at the end of the pipe, the third wire is connected to the steel pipe, and the cable is exited through a sealing device installed on the insulation plug. This option is used to route signal conductors inside engineering structures and technological premises.

The second option is a pipeline end element with a metal insulation plug and a cable outlet (KV ZIM). In this element, two wires of a three-core cable are connected to the break of the main signal wire, the third wire is connected to the steel pipe, and the cable is brought out through a sealing device installed on the pipe shell. This option is used to route signal conductors into special technological devices (carpets) installed outside engineering structures and buildings.

Intermediate cable outlets are designed to divide an extensive pipeline network into sections of a certain length, which provides the necessary accuracy when troubleshooting the control system. They are installed along the length of the route at distances determined by regulatory documentation (SP 41-105-2002) and agreed upon with the operating organizations. The intermediate cable outlet is made in the form of a special pipeline element, in which four wires of a five-core cable are connected to the break of the signal wires, the fifth wire is connected to the working pipe, and the cable itself is brought out through a sealing device installed on the pipe shell.

The end elements of the pipeline are installed at the end of the thermal insulation and are designed to combine a two-wire line into a single loop and protect the thermal insulation layer from moisture penetration. The connection of the signal conductors to each other at the end elements of the pipeline is made at the end of the insulating layer under the insulation plug.

The insulation resistance of each signal conductor of any element is at least 10 MΩ.

Installation and connection kits

The SODK wire connection kit (included in the kits of materials for sealing butt joints) is designed to connect the SODK wires and fix them on the heat-carrying pipe at a certain distance from it.

Delivery set for 1 joint:

1. wire holder - 2 pcs.
2. crimp coupling for connecting wires - 2 pcs.

1. solder, quantity per 1 joint - 2g
2. flux or solder paste- 1g
3. tape with adhesive layer - according to the table:

Outer diameter of steel pipe	Consumption of tape with adhesive layer per 1 joint
d, mm	m
57	0,5
76	0,7
89	0,85
108	1,02
133	1,26
159	1,5
219	2,1
273	2,6
325	3,1
377	3,55
426	4,05
530	5,02

The three-core output cable extension kit is used to extend the three-core cable of the UEC system at the cable terminals during pipeline installation.

Contents of delivery:

Three-core cable - 5 m;

Heat shrink tube with a diameter of 25 mm L= 0.12 m;

Tape mastic "Gerlen" - 0.2 m2;

Electrical tape - 1 roll for 10 sets;

Crimp coupling for connecting wires - 3 pcs;

Heat-shrink tube with a diameter of 6 mm L= 3cm - 3 pcs;

Consumables (not included in delivery):

Solder - 3g.
- flux or solder paste - 1.5 g.

Five-core cable extension kit output used to extend the five-core cable of the UEC system at the intermediate cable outlet during pipeline installation.

Contents of delivery:

Five-core cable - 5 m;

Heat shrink tube with diameters of 25 mm - 0.12 m;

Tape mastic "Guerlain" - 0.2 m2;

Electrical tape - 1 roll 1 - 8 sets;

Crimp sleeve for splicing wires - 5 pcs.

Heat shrink tube with a diameter of 6 mm L= 3cm - 5 pcs.

Consumables (not included in delivery):

Solder - 5g.
- flux or solder paste - 2.5 g.

Signal part consists of interface elements and devices:

1. Measuring and switching terminals for connecting devices at control and switching points of signal conductors.
2. Monitoring devices (detectors, indicators) portable and stationary.
3. Fault locating devices (pulse reflectometer).
4. Measuring instruments (insulation tester, megger, ohmmeter).
5. Cables for installation connection of terminals and connection of terminals with stationary control devices.

To switch signal conductors and connect devices to connecting cables at control and switching points, special switching boxes - terminals are used.

Terminals are divided into two main types: measuring and sealed.

Measuring The terminals are designed for prompt switching of signal conductors during measurements. The necessary switching and measurements are made using external plug connectors, without opening the terminal. Terminals of this type are installed in dry or well-ventilated engineering devices (ground or wall carpets, etc.) and technological rooms (central heating substation, electrical substation, etc.).

Sealed The terminals are designed for switching signal conductors in conditions of high humidity. The necessary switching and measurements are made using connectors installed inside the terminals. Access to them requires removal of the terminal cover. Terminals of this type can be installed in any technological devices(ground or wall carpets, etc.), structures and premises (in thermal chambers, in the basements of houses, etc.)

Types of measuring terminals:

End terminal (KT-11, KIT, KSP 10-2 and TKI, TKIM) - installed at control points at the ends of the pipeline;

End terminal with output to a stationary detector (KT-15, KT-14, IT-15, IT-14, KDT, KDT2, KSP 12-5 and TKD) - installed at the end of the pipeline, at the control point where connection to a stationary detector is provided ;

Intermediate terminal (KT-12/Sh, IT-12/Sh, PIT, KSP 10-3, TPI and TPIM) - installed at intermediate pipeline control points and at control points at the beginning of side branches.

Double end terminal (KT-12/Sh, IT-12/Sh, DKIT, KSP 10-4 and TDKI) - installed at the control point on the boundary of separation of control systems of associated projects;

Types of Sealed Terminals:

The end terminal is sealed - installed at control points at the ends of the pipeline;

Intermediate terminal (KT-12, IT-12, PGT and TPG) - installed at intermediate pipeline control points and at control points at the beginning of side branches.

Sealed connecting terminal (KT-16, IT-16, OT6, OT4, OT3, KSP 13-3, KSP 12-3, TO-3 and TO-4) - installed at those control points where it is necessary to combine several pipeline sections or several separate pipelines;

A sealed connecting terminal with access to a stationary detector (KT-16, IT-16, OT6, OT3, KSP 13-3, KSP 12-3 and TO-3) - installed at the control point where it is necessary to combine several separate pipelines into a single loop , and which provides for connecting a cable from a stationary detector;

Hermetic pass-through terminal (KT-15, IT-15, PT, KSP 12 and TP) - installed in places where polyurethane foam insulation breaks (in thermal chambers, in the basements of houses, etc.) for switching connecting cables or the device of an additional control point if it is necessary to use long connecting cables.

Compliance of terminals produced by NPK VECTOR, LLC TERMOLINE, NPO STROPOLYMER, JSC MOSFLOWLINE and terminals of the TermoVita series

OOO "TERMOLINE"	NPK "VECTOR"		NGO "STROYPOLYMER"	JSC "MOSFLOWLINE"
KT-11	IT-11	WHALE	KSP 10-2	End terminal.
KT-12	IT-12	PGT	No	----
KT-12/Sh	IT-12/Sh	PETE, DKIT	KSP 10-3, KSP 10-4	Intermediate terminal, double end terminal
KT-13	IT-13	KGT	KSP 10	----
KT-15	IT-15	KDT	KSP 12-5	Terminal with output to detector
KT-14	IT-14	KDT2	KSP 12-5 (2 pieces)	Terminal with output to detector (2 pieces)
KT-15	IT-15	PT, OT4	KSP 12	Passage terminal
KT-15/Sh	IT-15/Sh	KIT4	KSP 12-2, KSP 12-4	----
KT-16	IT-16	OT6, OT3 (2 pieces)	KSP 13-3, KSP 12-3 (2 pieces)	__

The terminals are connected to the UEC conductors using connecting cables: a 3-core cable (NYM 3x1.5) for connecting terminals at the end sections of the heating main and a 5-core cable (NYM 5x1.5) for connecting terminals at intermediate sections of the heating main. Connection and operation of the terminals is carried out in accordance with the technical documentation of the manufacturer.

Control devices

Monitoring the condition of the UEC system during pipeline operation is carried out using a device called detector. This device records the electrical conductivity of the heat-insulating layer. When water gets into the thermal insulation layer, its conductivity increases and this is recorded by the detector. At the same time, the detector measures the resistance of conductors connected in a closed circuit.

Detectors can be powered from a 220 Volt network (stationary), or from an autonomous 9 Volt power source (portable).

Stationary detector allows you to simultaneously monitor two pipes with a maximum length of 2.5 to 5 km each, depending on the model.

Table 1

Technical characteristics of stationary detectors

Options	Vector-2000	PIKKON				SD-M2
		DPS-2A	DPS-2AM	DPS-4A	DPS-4AM
Supply voltage, V	220 (+10-15)%	220 (+10-15)%				220 (+10-15)%
Number of controlled pipeline sections, pcs.	from 1 to 4	2		4		2
	up to 2500	up to 2500				5000
	more than 600	more than 200				more than 150
Insulation wetness indication, kOhm	less than 5 (+10%)	less than 5 (+10%)				Multi-level more than 100 from 30 to 100 from 10 to 30 from 3 to 10 less than 3
	10 DC	8 Direct current				4 Alternating current
	30	30				120 (2 tu.)
Operating ambient temperature, С˚	-45 - +50	-45 - +50		-45 - +50		-40 - +55
	no more than 98 (25 °C)	45÷75		45÷75		No data
Protection class from external influences		IP 55		IP 55		IP 67
Overall dimensions, mm	145x220x75	170x155x65		220x175x65		180x180x60
Weight, kg	no more than 1	no more than 0.7		no more than 1		0,75

When using a stationary detector SD-M2, it is possible to organize a centralized SODC of a branched heating network of considerable length (up to 5 km) from a single control center. For this purpose, the stationary detector has galvanically isolated contacts for each channel, which close when a malfunction occurs.

Connection and operation of stationary detectors is carried out in accordance with the technical documentation of the manufacturer.

The portable detector allows you to monitor a pipe with a maximum length of 2 to 5 km, depending on the model. One detector can control different areas pipelines that are not interconnected into a single system. The portable detector is not permanently installed at the site, but is connected to the controlled area by the employee conducting the inspection as part of its operation.

table 2

Technical characteristics of portable detectors

Options	Vector-2000	PIKKON DPP-A	PIKKON DPP-AM	DA-M2
Supply voltage, V	9	9		9
Length of one controlled section of the pipeline, m	up to 2000	up to 2000		5000
Indication of signal wire damage, Ohm	more than 600(+10%)	more than 200(+10%)		150
Test voltage on signal wires, V	10 DC	8 Direct current		4 Alternating current
Indication of wetness of PPU insulation, kOhm	less than 5 (+10%)	less than 5 (+10%)	Multi-level more than 1000 from 500 to 1000 from 100 to 500 from 50 to 100 from 5 to 50	Multi-level more than 100 from 30 to 100 from 10 to 30 from 3 to 10 less than 3
Current consumption in operating mode, mA	1,5	1,5		No more than 20
Operating ambient temperature, "WITH	-45 - +50	-45 - +50		-20 - +40
Operating ambient humidity, %	no more than 98 (25 °C)	45÷75		Splashproof
Overall dimensions, mm	70x135x24	70x135x24		135x70x25
Weight, g	no more than 100	no more than 170		150

Connection and operation of portable detectors is carried out in accordance with the technical documentation of the manufacturer.

Damage detection devices

Used to determine the location of damage pulse reflectometer, providing acceptable measurement accuracy. The reflectometer allows you to determine damage at distances from 2 to 10 km, depending on the model used. The measurement error is approximately 1-2% of the length of the measured line. The accuracy of measurements is determined not by the error of reflectometers, but by the error of the wave characteristics of all pipeline elements (wave impedance of the insulation moisture sensor). Depending on the amount of insulation moisture, the reflectometer allows you to determine the location of several places with reduced insulation resistance.

Technical characteristics of domestic pulse reflectometers

Name	FLIGHT-105	FLIGHT-205	RI-10M	RI-20M
Manufacturing plant	NPP "STELL", Bryansk		JSC "ERSTED", St. Petersburg
Measuring distance range	12.5 -25600 m	12.5-102400m	1- 20000 m	1m-50km.
Resolution	Not worse than 0.02 m	0.2% on ranges from 100 to 102400 m	1% of range	25 cm... 250 m (range)
Measurement error	Less than 1%	Less than 1%	Less than 1%	Less than 1%
Output impedance	20 - 470 Ohm, continuously adjustable	from 30 to 410, continuously adjustable	20 - 200 Ohm.	thirty. . 1000 Ohm.
Probing signals	Pulse amplitude 5 V, 7 ns - 10 μs;	Pulse amplitude 7 V and 22 V from 10 to 30-10 3 ns	Pulse amplitude 6 V, 10 ns - 20 μs;	Pulse amplitude of at least 10 V. 10 ns. .50 µs.
Stretching		Possibility of stretching the reflectogram around the measuring or zero cursor by 2,4,8, 16, ...131072 times	0.1 of range	0.025 of range
Memory	200 reflectograms;	up to 500 reflectograms	100 reflectograms	16 MB.
Interface	RS-232	RS-232	RS-232	RS-232
Gain	60 dB	86 dB	-20... +40 dB.	-20... +40 dB.
KU installation range (v/2)	1.000...7.000	1.000...7.000		1.00...3.00 (50 m/µs... 150 m/µs).
Display		LCD 320x240 pixels with backlight	LCD 128x64 pixels with backlight	LCD 240x128 pixels with backlight
Nutrition	built-in battery - 4.2÷6V network - 220÷240 V, 47-400 Hz network direct current- 11÷15V	built-in battery - 10.2-14 DC network - 11÷15V network - 220÷240	built-in battery - 12 V; mains - 220V 50Hz, via adapter. Continuous battery life is at least 6 hours (with backlight).	built-in battery - 12 V; mains - 220V 50Hz, via adapter. Continuous battery life is at least 5 hours (with backlight).
Power consumption	No more than 2.5 W	5 W	3 VA	4VA
Operating temperature range	- 10 °C + 50 °C	- 10 °C + 50 °C	-20С...+40С	-20С...+40С
dimensions	106x224x40 mm	275x166x70	267x157x62	220x200x110 mm
Weight	No more than 0.7 kg (with built-in batteries)		No more than 2 kg (with built-in batteries)	no more than 2.5 kg (with built-in batteries)

FLIGHT-205

Reflectometer REIS-205 along with the traditional pulse reflectometry method, in which the length of the line, the distance to places short circuit, breakage, low-resistance leakage and longitudinal increase in resistance (for example, in places where cores are twisted, etc.), additionally implements m skeleton measurement method.What allows you to accurately measure loop resistance, ohmic asymmetry, line capacitance, insulation resistance, and determine the distance to the location of high-resistance damage (lower insulation) or line break.

Connection and operation of pulse reflectometers is carried out in accordance with the technical documentation of the manufacturer.

Additional devices

Ground and wall carpets

Purpose

The carpet, both ground-mounted and wall-mounted, is designed to accommodate switching terminals and protects elements of the control system from unauthorized access.

The carpet is metal structure with a reliable locking device. There is a place inside the carpet for attaching the terminal.

Design

The design of systems must be carried out with the possibility of connecting the designed system to control systems for existing pipelines and pipelines planned in the future. Maximum length An extensive network of pipelines for the designed control system is selected based on the maximum range of control devices (five kilometers of pipeline).

The choice of the type of control devices for the designed section should be made based on the possibility of supplying (availability) of 220 V voltage to the designed section for the entire period of operation of the pipeline. In the presence of voltage, it is necessary to use a stationary fault detector, and in the absence of voltage, a portable detector with an autonomous power supply.

The choice of the number of devices for the designed section should be made taking into account the length of the designed pipeline section.

If the length of the designed section is greater than the maximum length controlled by one detector (see characteristics in the passport), then it is necessary to divide the heating main into several sections with independent monitoring systems.

The number of plots is determined by the formula:

N= Lnp/Lmax,

where /_pr is the length of the designed heating main, m;

L^ ax -maximum range of the detector, m.

Round the resulting value up to a whole number.

Note. One portable detector can monitor several independent sections of heating networks.

Test points are designed to allow operating personnel access to signal wires to determine the condition of the pipeline.

Control points are divided into end and intermediate. End control points are located at all end points of the designed pipeline. When the length of the section is less than 100 meters, it is allowed to install only one control point, with a loop of signal conductors under a metal plug at the other end of the pipeline.

Control points are located so that the distance between two adjacent control points does not exceed 300 m. At the beginning of each side branch from the main pipeline, if its length is 30 m or more (regardless of the location of other control points on the main pipeline), an intermediate terminal is placed .

At the boundaries of adjacent heating network projects, at the points of their connection, it is necessary to provide control points and install double end terminals that allow the UEC system of these sections to be combined or separated.

When connecting conductors of the UEC system in series at the end of the insulation (passage of pipelines through thermal chambers, basements of buildings, etc.), the connection of conductors must be made only through terminals.

The maximum cable length from the pipeline to the terminal should not exceed 10 m. If it is necessary to use a cable with a longer length, it is necessary to install an additional terminal as close as possible to the pipeline.

Each control point must include:

• pipeline element with output cable;
• connection cable;
• switching terminal.

It is not recommended to place control points in thermal chambers due to humidity in the chamber, however, it is allowed only in cases where the placement of a ground carpet is associated with any difficulties (damage to the appearance of the city, impact on traffic safety, etc.). In these cases, the terminals placed in thermal chambers must be sealed. In the basements of houses, the placement of control points is not recommended if the designed heating main and the house belong to different departments, since in these cases a conflict is possible during the operation of pipelines (due to problems with access to control points and the safety of elements of the UEC system). In these cases, it is recommended to equip the control point with a ground carpet installed 2 - 3 meters from the house.

Installation of terminals at intermediate and end control points is carried out in ground or wall carpets of the established type. At the end points of the pipeline, it is allowed to install terminals in the central heating substation.

Control system design rules

(in accordance with SP 41-105-2002)

1. As the main signal wire, a marked wire is used, located on the right in the direction of water supply to the consumer on both pipelines (conventionally tinned). The second signal conductor is called transit.
2. Conductors of any branches must be included in the break of the main signal conductor of the main pipeline. It is prohibited to connect side branches to the copper wire located on the left along the water supply to the consumer.
3. When designing interfacing projects, intermediate cable outlets with double end terminals are installed at the junction points of the routes, which make it possible to combine or separate the control systems of these projects.
4. At the ends of the routes of a single project, cable terminations with end terminals are installed. One of these terminals may have an output to a stationary detector.
5. Along the entire route, at distances not exceeding 300 meters, intermediate cable outlets with intermediate terminals are installed.
6. Intermediate cable terminals on heating mains must be additionally installed on all side branches longer than 30 meters, regardless of the location of other terminals on the main pipe.
7. The control system must ensure that measurements are taken on both sides of the controlled section when its length is more than 100 meters.
8. For pipelines or end sections less than 100 meters in length, it is permissible to install one end or intermediate cable outlet and its corresponding terminal. At the other end of the pipeline, a line of signal conductors is connected into a loop under a metal insulation plug.
9. When connecting signal conductors in series, at the end of polyurethane foam insulation (passage through chambers, basements of buildings, etc.), as well as when combining control systems for different pipes (supply with return, heating network with hot water supply), connect the cables between sections of pipelines only using walk-through, pooling or sealed terminals.
10. The specification must indicate the length of the cable for a specific point, taking into account the depth of the heating main, the height of the carpet, the distance of its (carpet) removal to the mainland soil and 0.5 meters of reserve.
11. The maximum cable length from the pipeline to the terminal should not exceed 10 meters. In the case when it is necessary to use a cable with a longer length, it is necessary to install an additional pass-through terminal. The terminal is installed as close to the pipeline as possible.
12. The installation of stationary detectors on pipelines that enter process rooms with constant access by maintenance personnel is mandatory.

Control system diagram

The control system diagram consists of a graphical representation of the signal conductor connection diagram, repeating the route configuration.

The diagram shows:

F installation locations of cable outlets and control points, indicating the types of terminals, detectors and types of carpets (ground or wall) in graphical form;

F indicates the symbols of all elements used in the control system diagram;

F, characteristic points corresponding to the installation diagram are indicated: branches from the main trunk of the heating main (including drains); turning angles; fixed supports; diameter transitions; cable outlets.

The diagram is accompanied by a data table for characteristic points indicating the following parameters:

F point numbers by project documentation;

F pipe diameter at the site;

F is the length of the pipeline between points according to the design documentation for the supply pipeline;

F is the length of the pipeline between points according to the design documentation for the return pipeline;

F is the length of the pipeline between points according to the joint diagram (separately for the main and transit signal conductors of each pipeline);

F length of connecting cables at all control points (separately for each pipeline).

Additionally, the control scheme must contain:

F diagrams for connecting connecting cables to signal conductors;

F diagrams for connecting cables to terminals and stationary detectors;

F specification of the devices and materials used;

F sketches of markings of external and internal connectors in directions.

The design of the control system must be agreed upon with the organization accepting the heating main for balance.

Installation of the UEC system

Installation of the UEC system is carried out after welding the pipes and conducting a hydraulic test of the pipeline.

When installing pipeline elements on construction site, before starting welding of the joint, the pipes must be oriented in such a way as to ensure the location of the wires of the UEC system along the side parts of the joint, and the leads of the wires of one pipeline element are located opposite the leads of the other, thereby ensuring the possibility of connecting the wires over the shortest distance. It is not allowed to place signal wires at the bottomquarter joint.

At the same time, the installed pipeline elements are checked for insulation condition (visually and electrically) and the integrity of the signal conductors. And all pipeline elements with cable outlets require additional measurement of the yellow-green wire of the outlet cable and the steel pipe. Resistance should be ≈ 0 ohm.

When carrying out welding work, the ends of the polyurethane foam insulation should be protected with removable aluminum (or tin) screens to prevent damage to the signal wires and the insulating layer.

During installation work, carry out accurate measurements of the lengths of each pipeline element (along a steel pipe), recording the results on the as-built diagram of butt joints.

The connection of signal conductors is made strictly according to the design diagram of the control system.

Conductors of any branches must be included in the break of the main signal conductor of the main pipeline. It is prohibited to connect side branches to the copper wire located on the left along the water supply to the consumer.

The main signal wire is a marked wire located on the right in the direction of water supply to the consumer on both pipelines (conventionally tinned).

Signal conductors of adjacent pipeline elements must be connected using crimp couplings with subsequent soldering of the conductor junction. Crimping couplings with inserted wires should only be done with a special tool (crimping pliers). Crimping is carried out with the middle working part of the tool marked 1.5. It is prohibited to perform crimping of crimp couplings with non-standard tools (nippers, pliers, etc.)

Soldering must be performed using inactive fluxes. Recommended flux LTI-120. Recommended solder POS-61.

When connecting wires at joints, all signal wires are fixed on wire holders (stands), which are attached to the pipe using tape (adhesive tape). The use of chlorine-containing materials is prohibited. It is also prohibited to run insulation over the wires, securing the posts and wires at the same time.

When installing pipeline elements with cable outlets, mark the free end of the signal cable from the supply pipeline with insulating tape.

Minstallation of conductors of the UEC system duringjoint insulation work

1. Before installing signal wires, the steel pipe is cleaned of dust and moisture. The polyurethane foam at the ends of the pipe is cleaned: it must be dry and clean.

3. Straighten the wires.

4. Cut the wires to be connected, having previously measured the required length. Clean the wires with sandpaper.

5. Connect the wires at the opposite end of the pipeline element or mounted section and check them for absence of short circuit to the pipe.

6. Connect both wires to the device and measure the resistance: it should not exceed 1.5 Ohms per 100 m of wires.

7. Clean the section of steel pipe from rust and scale. Connect one cable of the device to the pipe, the second to one of the signal conductors. At a voltage of 250 V, the insulation resistance of any pipeline element must be at least 10 MΩ, and the insulation resistance of a 300 m long pipeline section must not be less than 1 MΩ. As the length of the conductors increases, their resistance will decrease. The actual measured insulation resistance must be no less than the value determined by the formula:

Rfrom = 300/ Lfrom

Rfrom- measured insulation resistance, MOhm

Lfrom- length of the pipeline section being measured, m.

Too little resistance indicates increased moisture in the insulation or contact between the signal wires and the steel pipe.

8. Secure the wires at the junction using stands and adhesive tape. Do not apply adhesive tape over the wires, securing the posts and wires at the same time.

9. Connect the wires according to the instructions “Connection of conductors of the UEC system”.

10. Perform thermal and waterproofing of the joint. The type of thermal and waterproofing is determined by the project.

11. Upon completion of work, check the insulation resistance and resistance of the wire loops of the UEC system of the mounted sections. Record the measurement results in the “Work Log”.

If the signal wire breaks at the exit from the insulation, you need to remove the polyurethane foam insulation around the broken wire in an area sufficient for a reliable connection of the wires. The connection is made using crimp sleeves and soldering. Extension of short wires is done in the same way.

When installing signal system wires at each joint, the signal circuit and insulation resistance are monitored in accordance with the diagram below:

After waterproofing, check the insulation resistance and resistance of the wire loops of the UEC system of the installed sections, and record the obtained data in the work completion report or measurement report.

Control measurements of system parametersUEC topicson pipeline elements

1. Straighten the wire leads and lay them so that they are parallel to the pipe. Carefully inspect the wires - there should be no cracks, cuts or burrs on them. When taking measurements on cable terminals, remove the outer insulation of the cable at a distance of 40 mm. from its end and insulate each core by 10-15 mm. Clean the ends of the wires using emery cloth until a characteristic copper sheen appears.

2. Short the two wires at one end of the pipe. Make sure that the contact between the wires is reliable and the wires do not touch the metal pipe. Perform similar operations to check the wires in the taps. For T-branches, the wires must be closed at both ends of the main pipe, forming a single loop. When ending a pipeline section with a cable outlet element, connect the corresponding cable cores running in the same direction.

3. Connect a device for measuring insulation resistance and monitoring circuit integrity (STANDARD 1800 IN or similar) to the conductors at the open end and measure the resistance of the wires: the resistance should be in the range of 0.012-0.015 Ohms per meter of conductor.

4. Clean the pipe, connect one of the device cables to it, and connect the second cable to one of the wires. At a voltage of 500 V, if the insulation is dry, the device should show infinity. The permissible insulation resistance of each pipe or other pipeline element must be at least 10 MOhm.

5. When measuring the insulation resistance of a pipeline section consisting of several elements, the measuring voltage should not exceed 250 V. The insulation resistance is considered satisfactory at a value of 1 MΩ per 300 meters of pipeline. When measuring the insulation resistance of pipeline sections with different lengths, it should be taken into account that the insulation resistance is inversely proportional to the length of the pipeline.

Installation of control points

Ground carpets are installed on the mainland soil next to the pipeline at the points indicated on the control system diagram. The installation location of the ground carpet at a specific point is determined locally by the construction organization, taking into account ease of maintenance. The internal volume of the ground carpet should be filled with dry sand from the base to a level of 20 centimeters from the top edge.

After installing the carpet, its geodetic reference is carried out. When installing carpets on heating mains laid in bulk soils, additional measures should be taken to protect the carpet from subsidence and damage to the signal cable.

When installing a carpet on heating mains laid in bulk soils, it is necessary to take additional measures to protect the carpet from soil subsidence.

The outer surface of the carpet is protected with an anti-corrosion coating.

The wall carpet is attached to the wall of the building, either from the outside or from the inside. The wall carpet is attached 1.5 meters from the horizontal surface (floor of a building, chamber or ground).

Connecting cables from pipeline elements with a sealed cable outlet to the carpet are laid in pipes (galvanized, polyethylene) or in a protective corrugated hose. Laying the connecting cable inside buildings (structures) to the installation site of the terminals must also be carried out in galvanized pipes or in protective corrugated hoses that are fixed to the walls. It is possible to use PE pipes. Laying the connecting cable at the point where the thermal insulation is broken (in a thermal chamber, etc.) must also be carried out in a galvanized pipe fixed to the wall.

Installation of terminals and detectors should be carried out in accordance with the markings given on the attached diagrams and accompanying documentation for these products.

Upon completion of installation, mark the nameplates (tags) on each terminal according to the connector marking sketches in directions.

On inside Weld the covers of each carpet with the project number and the number of the point where this carpet is installed.

At the end of the work, check the insulation resistance and resistance of the wire loops of the UEC system and document the measurement results in an inspection report of the control system parameters. In the same act, the lengths of the signal lines of each section of the pipeline and connecting cables at each measuring point should be recorded, separately for the supply and return pipelines. Measurements should be carried out with the detector turned off.

Acceptance of the UEC system into operation.

Acceptance of the UEC system must be carried out by representatives of the operating organization. In the presence of representatives of technical supervision, the construction organization and the organization that installed and adjusted the UEC system during a comprehensive inspection, the following is carried out:

Measurement of ohmic resistance of signal conductors;

Measurement of insulation resistance between signal conductors and working pipe;

Recording reflectograms of heating network sections using a pulsed reflectometer for use as a reference during operation. It is recommended to create a primary data bank by taking reflectograms of each wire between the nearest measuring points from opposite directions;

Correct settings control devices(locators, detectors) transferred for operation for a given object.

All measurement data and initial information (length of pipelines, lengths of connecting cables at each control point, etc.) are entered into the acceptance certificate of the UEC system.

The UEC system is considered operational if the insulation resistance between the signal conductors and the steel pipeline is not lower than 1 MOhm per 300 m of the heating main. To control the insulation resistance, a voltage of 250V should be used. The loop resistance of the signal conductors should be in the range of 0.012 - 0.015 Ohms per meter of conductor, including connecting cables.

Rules for operating UEC systems.

To quickly identify faults in UEC systems, it is necessary to ensure regular monitoring of the system condition.

The state of the UEC system must be constantly monitored by a stationary detector. Portable detectors are used only on sections of heating mains where it is not possible to install a stationary detector (lack of a 220 V network) or during production repair work. During repair work, the monitoring system of the repaired area between the nearest measuring points is removed from the general system. The general control system is divided into local sections. During repairs, the state of the UEC system of each of these sections, separated from the stationary detector, is monitored using a portable detector.

Monitoring the state of the UEC system includes:

1. Monitoring the integrity of the signal conductor loop.

2. Monitoring the insulation condition of the controlled pipeline.

If a malfunction of the UEC system is detected (breakage or moisture), it is necessary to check the presence and correct connection of terminal connectors at all control points, and then take repeated measurements.

When confirming malfunctions of UEC systems of heating mains that are under warranty from a construction organization (the organization that installs, commissions and commissions the UEC system), the operating organization notifies the construction organization about the nature of the malfunction, which searches and determines the cause of the malfunction.

Locating damage locations

The search for damage sites is carried out on the principle of pulse reflection (pulse reflectometry method). The signal wire, the working pipe and the insulation between them form a two-wire line with certain wave properties. Moistening of the insulation or a wire break leads to a change in the wave characteristics of this two-wire line. Work on troubleshooting the control system is carried out instrumentally using a pulse reflectometer and a megger in accordance with the technical documentation for these devices. This work consists of the following stages:

1. A single section of pipeline with a broken signal wire or with reduced insulation resistance is determined using an indicator (detector) or a megger. A single section is defined as the section of the heating network between the nearest measuring points.

2. The wires of the UEC system are decommutated in a designated area.

3. Next, reflectograms of each wire are taken separately from opposite directions. If there are primary reflectograms taken during delivery of the UEC system, they are compared with the newly obtained reflectograms.

4. The obtained data is superimposed on the joint diagram. That is, the distances from the reflectograms are compared with the distances on the joint diagram.

5. Based on the results of data analysis, the pipeline is excavated for repair work. After excavation, it is possible to carry out control openings of the insulation in the area where the signal wires pass to obtain clarifying information.

Types of faults recorded by the monitoring system on pipelines with polyurethane foamisolation.

A. Signal wire break

According to the parameters of the UEC system, it is characterized by the absence or increased value of loop resistance.

1. Mechanical damage to the external insulation of pipelines and connecting cables.

2. Fatigue breakage of signal wires during thermal cycles in places of mechanical stress (cuts, breaks, pulling, etc.)

3. Oxidation of the connection points of signal wires inside the external insulation of pipelines and in the places where connecting cables are connected or extended (lack of soldering, overheating of the soldered joint, use of active fluxes without flushing the connection.)

4. Switching breaks on terminals (defects in solder connections, oxidation, deformation and fatigue of spring contacts of switching connectors, loosening of screw clamps of connecting blocks).

B. Wetting of polyurethane foam insulation.

According to the parameters of the UEC system, it is characterized by a reduced insulation resistance.

1. Leakage of external insulation.

A. Mechanical damage to external insulation and connecting cables (breaks and breakdowns).

b. Defects in the welds of the polyethylene shell of fittings (failure to penetrate, cracks).

V. Leakage of joint insulation (lack of penetration, lack of adhesion of adhesive materials).

2. Internal wetting.

A. Defects in welds of steel pipes.

b. Fistulas from internal corrosion.

B. Signal wire shorted to pipe.

According to the parameters of the UEC system, it is characterized by a very low insulation resistance.

Causes:

Destruction of the film of polyurethane foam components between the pipe and the signal wire during thermal cycles. A manufacturing defect is the proximity of the wire to the pipe. Detection is not difficult and is done in the same way as searching for wet spots.

Description:

A. V. Aushev, General Director of Termoline LLC

S. N. Sinavchian, Ph.D. tech. Sciences, Associate Professor of the Department of RL-6 MSTU. N. E. Bauman

Central heating and hot water supply networks are a heat-insulated metal pipe that creates a sealed circuit for moving liquids under pressure up to 1.6 MPa. In a city, the task of monitoring its tightness is determined both by the need to maintain its functionality, which means reducing coolant losses and saving thermal energy, and by the safety requirements of citizens.

One of the methods for monitoring the tightness of a metal pipeline is to control the pressure in it. However, a number of reasons, such as the presence of coolant flow by the consumer, the dependence of pressure on temperature in a closed volume and the low accuracy of pressure gauges, make this method very crude.

Determination of leaks during ducted and ductless laying of heat pipes

Heat pipes can be divided into two groups:

• having an additional sealed thermal insulation shell along the entire length (ductless laying),
• with a non-hermetic insulation shell, which mainly performs the functions of its fixation (channel gasket).

Let's consider these groups from the point of view of ensuring the possibility of detecting and localizing the location of a coolant leak.

Channel gasket They are used, as a rule, for pipelines whose insulating layer is not protected by an additional waterproofing shell along the entire length. For channel-laying pipelines, leak detection is only possible using special equipment. Such equipment is acoustic and correlation leak detectors, the operating principle of which is based on determining the location of a powerful source of sound and vibration vibrations when liquid flows outside a sealed circuit.

Thermal imagers are also used, the data of which allows one to determine the location of the maximum level of infrared radiation of the soil, heated by the coolant flowing uncontrollably from the pipeline. Sometimes chemical analysis of groundwater and wastewater is used, determining the presence of coolant in which indicates a pipeline rupture.

However, in urban conditions, the presence of adjacent communications (where the coolant goes), as well as the unevenness of the depth and surface of the soil above the pipeline, introduce significant difficulties in determining the location of the leak when using thermal imagers and chemical analysis of water. Finding the location of a pipeline rupture during channel laying, as a rule, consists of integrated approach when performing these works. In addition, none of the listed methods can be implemented with cheap, permanently installed equipment, so there is no economically accessible possibility of automatic notification of an emergency situation on the pipeline.

For ductless installation Only pipelines whose thermal insulation layer is protected by an additional external waterproofing shell are applicable. However, this shell not only serves as a barrier to external ground or melt water, but also is an obstacle to the penetration of coolant into the coating if the metal pipe loses its tightness. At the same time, the flow of coolant into the bedding is not accompanied by a powerful release of acoustic noise and vibration, as happens with channel laying, which is the reason low efficiency use of acoustic and correlation methods.

The only way (from those given above for channel-laying pipelines) to determine the presence and location of depressurization of a metal pipeline or outer shell is the use of thermal imagers. However, in a city environment this method cannot be considered accurate, and automation of emergency notification is not available.

Systems for operational remote monitoring of pipelines

The use of an online remote monitoring system (ORMS) for pipelines in polyurethane foam (PUF) insulation is the only possible guaranteed way to monitor the insulation condition of a channel-laying pipeline. SODK is a complex of an instrumentation part and a pipe part, consisting of two copper conductors located in the thickness of the insulation parallel to the metal pipeline along its entire length (Fig.). When the insulation gets wet due to depressurization of the metal pipe and the outer polyethylene sheath, its resistance sharply decreases, which is detected by stationary insulation condition monitoring devices.

According to data from SODC detectors, it is necessary to record them at least once every two weeks. The collection of information is traditionally carried out by employees of the operation service - “crawlers”, whose task is not only to bypass many points, but also to record on paper data from stationary and portable insulation state detectors. The volumes of implementation of polyurethane foam-insulated pipelines equipped with SODC, which are increasing every year, do not allow them to be effectively controlled by bypass, which is the reason for the need to use dispatch systems (see reference).

Benefits of dispatching

Let us note once again that automatic control of the tightness of a metal pipe and the outer shell is implemented only for pipelines in PPU-insulated channel laying, equipped with ODSK. Continuous remote monitoring of the condition of such pipelines has the following advantages over the traditional method of collecting information:

• Instant notification about changes in the condition of the pipeline and the integrity of the system.

According to clause 9.2: “To promptly identify damage to the pipeline, it is necessary to ensure regular monitoring of the condition of the ODS (at least twice a month) using a detector.” During this time, if a metal pipe breaks, the entire section of the pipeline with PPU insulation may fail. It is possible for water to spread inside the thermal insulation of the pipeline (between the PPU insulation and the shell, as well as the PPU insulation and the metal pipe) over tens of meters in a short time. Effective operation of such sections is impossible in the future; the process of their wetting is irreversible, which leads to the need to re-lay tens of meters of pipeline.

We especially note that the loss of integrity of a metal pipe in PPU insulation is not accompanied by a sharp drop in pressure in the system, as happens in channel-laying pipelines. This is due, firstly, to the tightness of the polyethylene shell, and secondly, to the channelless method of laying the pipeline in PPU insulation. The pressure in the pipe can be maintained even when network water spreads along the pipeline for tens of meters. This fact indicates the impossibility of detecting an emergency situation on a pipeline in polyurethane foam insulation, except with the help of a working ODS. Within two weeks of not taking readings from the detectors, the soil may be washed away, which will lead to the collapse of the load-bearing layers of the soil, and this, in turn, in a city environment can lead not only to great material damage, but also to human casualties.

• Screening out false calls.

The specificity of the work of the “crawler” determines the possibility of them recording false information or the failure to transmit real information about the readings of the detectors to the emergency services. Often, when response teams arrive, the detector readings correspond to the normal operation of the pipeline, and a false call is associated with the incompetence of the “inspector”. But it is worse if he did not record or transmit information about the accident on the highway. Operations service employees or a third-party organization (working under a contract) responsible for taking readings on site using a walk-through method may actually not visit the controlled objects, while they themselves record the “normal” state of the pipeline, since they know that at this stage no one is watching controls. Then the time for soil erosion exceeds two weeks, which significantly aggravates the consequences of a pipeline accident and increases the length of the required replacement. By excluding the human factor from the emergency notification chain, we significantly increase the reliability of PPU-insulated pipelines.

• Elimination of the corruption component.

A situation is possible when an employee of the operation service, responsible for taking readings on site, for some reason deliberately tries to hide or distort the real condition of the pipeline - for example, the same employee accepted for operation a pipeline of inadequate quality or with a faulty ODS. By organizing remote control, it is possible to eliminate the corruption component that occurs when pipelines are accepted for operation. Such an approach will also provide more high quality of delivered pipelines, since one employee takes it into operation, and controls it through the PD by another.

• Application of multi-level detectors.

As a rule, single-level stationary damage detectors are installed on heating mains. They signal that the pipeline is wet, at which its insulation resistance decreases only to 5 kOhm. The use of multi-level detectors with current output makes it possible to detect pipeline defects at an early stage of its formation. Detection of the insulation resistance of the monitored pipeline occurs in six ranges, the upper of which corresponds to the ideal insulation state (more than 1 MOhm). The speed at which the resistance decreases from the upper range to the lower (less than 5 kOhm) indicates the size of the defect: the higher the speed, the more significant the pipeline defect.

• Ease of perception of received information, its processing and storage.

Today, all information received from “crawlers” is stored mainly on paper and is practically not amenable to statistical processing. The data collected using the dispatch system is not only more voluminous, complete and reliable, but also makes it possible to process it using various mathematical analysis algorithms. This allows you to filter out seasonal changes pipeline insulation conditions, false alarms, errors caused by human factors. The use of special software allows you to automatically generate reports on the condition of pipelines, monitor the nature and speed of response of personnel on site, and, when a sufficient sample has been accumulated, conduct a statistical analysis of information on the use of pipelines with polyurethane foam insulation.

• Flexibility of the dispatch system.

The stability and quality of operation of any telemetry system depend on the correct organization of the architecture for the interaction of its components. The usual structure of a dispatch system involves collecting data from geographically distributed controlled objects (often of the same type) into a single center. There are other options: multi-level construction of control rooms, local nodes for collecting or relaying data and others, but they do not change the essence of the centralized construction of the system. Moreover, the size of the system, depending on the object, can be either small (in the case of a block, an enterprise) or gigantic (branch, city, region).

• Economic expediency.

The role of automation and modernization of technological equipment of utility networks in modern reality is not only to improve the quality of service to the population, but also to reduce the cost of providing heat and hot water transport services. Important economic factors for reducing operating costs are the absence of a wage fund for “linemen”, their material support, and the absence of the need for training, control and accounting. There are also no additional difficulties associated with organizing access for “inspectors” to the premises where the detectors are installed. Of particular importance is the speed of delivery of information about an emergency situation, which is the main positive economic indicator.

The listed advantages of dispatch systems for the readings of pipeline condition detectors in polyurethane foam insulation became the reason for their use back in the early 2000s. The first mentions of positive effects were published in. At the moment, in one of the heating networks of the Moscow region, several data transmission systems operate simultaneously, exchanging information both via cable lines and via a GSM channel.

Methods for implementing data transmission systems

First way is the integration of stationary damage detectors as primary sources of information into the architecture of existing telemetry systems that perform monitoring and control tasks technological equipment heating points. The implementation of this method is possible if the SODC detector has the hardware ability to transfer data to the input lines of a remote controller (the detector must be equipped with special outputs for data transfer such as “current output” or “dry contact”). Heat network employees must have high professional skills to successfully visualize, analyze and store detector data on the control panel.

Both cable and GSM data transmission channels are used. This method of data transmission has been implemented for monitoring and managing a number of heating points in Moscow, Mytishchi, Reutov, St. Petersburg, and Astana.

Second way focused on the use of GSM telemetry systems, which have found application in the electric power industry, gas industry, banking sector, and security and fire alarm systems. High competition between manufacturers of such complexes is the reason for the emergence of large quantity reliable and cheap GSM controllers, the use of which for monitoring the condition parameters of pipelines in polyurethane foam insulation is a cost-effective and easy-to-implement solution. The main requirements for GSM telemetry systems are the ability to transfer data from the detector to the controller and the availability of software control panel. This software must provide:

• continuous unlimited control over remote objects;
• visualization of the location of controlled objects on a map of a populated area;
• visual and acoustic notification in case of an accident;
• individual configuration of the “Alarm” signal level for each object;
• stability of data transmission when duplicating various transports (modem connection, SMS, voice connection);
• the ability to transmit and visualize data from security sensors, temperature sensors, pressure sensors, etc.;
• the ability to automatically poll objects;
• sending SMS to the phones of responsible persons in case of emergency situations;
• personalized management and storage of information about operator actions in the event log;
• user-friendly interface, smooth operation, easy operation, etc.

The switching of GSM controllers with detectors, installation and configuration of remote controllers is carried out independently by employees of instrumentation departments or special units, which is greatly simplified due to the availability of detailed instructions. The task of creating a local dispatch console (LDP) at the level of a heating network enterprise is easy to accomplish, as it involves installing and configuring free and intuitive software. This method was implemented by enterprises in Novosibirsk, Mytishchi, Zheleznodorozhny, Dmitrov.

Third way dispatching the readings of SODK detectors is proposed in . If the operating organization does not see the need to create its own LDP (lack of proper funding, personnel or third-party organization appropriate level preparation, small number of objects), it is possible to use the services of the integrated dispatch console (UDP). The EDP, located in Shchelkovo, Moscow Region, receives information from GSM controllers configured to work with EDP, installed on the territory of the Russian Federation, the Republic of Kazakhstan and the Republic of Belarus.

Emergency notification of the responsible person of the operating organization in the event of an emergency occurs in any way convenient for him ( Personal Area on the ODP website, email, cell phone, dispatch service, etc.). A scheduled survey is also provided according to a schedule approved by the operating organization.

The operating organization must ensure safety at the installation site of the detector and remote GSM controller installed equipment, his uninterruptible power supply and a satisfactory level of GSM signal (if necessary, use a repeater).

Subsequently, remote transfer of data to a newly created LDP by the operating organization is possible. Thus, the use of DDP services becomes a test option for organizing your own LDP.

The method of dispatching detector readings is determined at the level of design work, since the specification, and therefore further financing, is formed by a specialist of the design organization, therefore one of the important tasks of the operating organization is to draw up a complete technical specification indicating the requirements for dispatching the designed pipeline.

Based on the provided technical specifications, the designer must determine the location and configuration of the pipeline control point equipped with a damage detector. Required condition The constant functioning of such a control point is the presence of a 220 V, 50 Hz power supply. Also supplied are complete sets of control points for operating in autonomous mode, however, their use is possible only in exceptional cases, since regardless of the type of power source (solar panel or batteries), kits for battery life provide only periodic monitoring of the pipeline insulation condition, which is the main way to reduce energy consumption.

The experience of implementation and delivery of equipment for dispatching the readings of pipeline condition detectors in polyurethane foam insulation indicates timeliness, sufficient high level equipment and economic efficiency of this area. A professional approach allows you to fully automate the process of reporting emergencies on pipelines of heating networks, which is only possible for pipelines equipped with ODS. At the same time, it is proposed various ways implementation of monitoring of detector readings for various levels vocational training heating network personnel.

Literature

1. STO 18929664.41.105–2013. System for operational-remote monitoring of pipelines with thermal insulation made of polyurethane foam in a polyethylene sheath or steel protective coating. Design, installation, acceptance, operation.
2. Kashinsky V.I., Lipovskikh V.M., Rotmistrov Ya.G. Experience in operating pipelines in polyurethane foam insulation at OJSC Moscow Heating Network Company // Thermal Energy. 2007. No. 7. pp. 28–30.
3. Kazanov Yu. N. Organizational and technical modernization of the heat supply system of the Mytishchi region // Heat supply news. 2009. No. 12. pp. 13–26.
4. Termoline LLC. Album technical solutions on the design of operational-remote monitoring systems for pipelines in polyurethane foam insulation. M., 2014.

PSK Polistroy, in addition to manufacturing products with polyurethane foam, provides services for insulating joints on heating mains, installation and commissioning of the UEC system, delivery of the UEC system at the operating organization’s facility, diagnostics and repairs.

Insulation of joints on heating mains

Steel ones have already proven their effectiveness in our country. The most “delicate” point when laying them is the insulation of the joints. The pipe itself is protected from corrosion at the factory, but the joints require good sealing. Even groundwater do not approach the surface of the pipe; dew may fall on them during a heat outage. Moisture will get in through the joint and the entire pipe will corrode.

The better the insulation, the less chance there is of emergency situation. Most effective method connections are the use of couplings. We offer heat-shrinkable, electric-welded, galvanized couplings, as well as hot-melt adhesive and foam kits.

We insulate joints of pipes with a diameter of 110 to 1600 mm.

Installation and commissioning of the UEC (SODK) system

The UEC system helps to monitor the condition of the thermal insulation layer of the heating network and detect moisture spots. This system works not only during operation, but also during installation. You can monitor how well the joints are insulated. With its help, accidents are prevented, because information is received in advance.

SODK is included in the mandatory program for laying pipelines in polyurethane foam insulation in accordance with GOST 30732-2006. The cost of the system is no more than 2% of the total cost of the project, and the benefits from it are enormous. It should be noted that one device with a portable detector is capable of monitoring several objects.

The system includes:

• signal conductors in thermal insulation;
• terminals at points of control and switching of signal conductors;
• cables for connecting signal conductors to terminals at control points;
• portable and stationary detectors;
• instruments for determining the exact location of damage or leakage;
• insulation testers;

The PSK Polistroy company provides services for the design and calculation of UEC systems, installation of UEC systems on the route.

Delivery of the UEC system at the operating organization's facility

After installation and debugging, the company’s specialists will test all pipeline elements. After testing, the parameters of the UEC system are examined and a preliminary acceptance certificate is issued. The final delivery of the heating network control system to the operating organization is carried out installation organization together with the company PSK Polistroy.

Diagnostics and repair

If a leak appears during operation of the heating network, it is not difficult to detect it using the UEC system. The insulation on the signal wires becomes wet and the signal weakens or is interrupted. The specific location is determined by a device - a reflectometer.

Reflectometers detect breakage of signal conductors and wetness of the insulating polyurethane foam layer. It is important that during diagnostics the operation of the heating network does not stop. These devices are able to indicate a problem even before damage detectors are triggered, store the results of previous measurements, and connect to a computer to build dynamics.

PSK Polistroy specialists will not only find the location and cause of the disruption to the heating network, but also eliminate the pre-emergency situation.

We will be glad to cooperate with you!

ASSOCIATION OF PRODUCERS AND CONSUMERS OF PIPELINES WITH INDUSTRIAL

POLYMER INSULATION

Standard of the organization NP "Association PTIPI"

STO NP "Association PPTIPI" - * - 1 – 2012

DESIGN, INSTALLATION, ACCEPTANCE AND OPERATION

OPERATIONAL REMOTE CONTROL SYSTEMS (SODC)

PIPELINES WITH THERMAL INSULATION FROM POLYURETHANE FOAM

IN POLYETHYLENE SHELL OR STEEL PROTECTIVE
COATINGS

First edition

Moscow

1. General Provisions. 2

2. Technical requirements. 2

3. Design of SODK. 6

4. Installation of SODK. 8

5. Acceptance of SDSK into operation.. 11

6. Operation and repair of SODK. 13

7. Application. 14

8. Application. 15

9. Application. 18

10.Appendix. 19

11.Appendix. 20

12.Appendix. 21

1. General provisions

1.1. For pipelines with thermal insulation made of polyurethane foam in a polyethylene sheath or steel protective coating, it is mandatory to have an operational remote control system (ORS), according to GOST clause 5.1.9.

1.2. The operational remote monitoring system (ORC) is designed to monitor the condition of the thermal insulation layer of polyurethane foam insulated pipelines and detect areas with high insulation moisture.

1.3. The basis for the operation of the UEC system is physical property polyurethane foam, which consists in decreasing the value of electrical resistance (Riz.) with increasing humidity (in a dry state, the insulation resistance tends to infinity).

1.4. The UEC system consists of the following elements:

Signal conductors in the heat-insulating layer of pipelines, running along the entire length of the heat pipelines.

Cables (or ready-made cable extension kits).

Terminals (mounting boxes with cable entries, terminal block and connectors).

The damage detector is stationary and portable.

The damage locator is portable (pulse reflectometer) or stationary.

Control and installation tester (high-voltage megohmmeter with the function of measuring conductor resistance).

Ground and wall carpets.

Tools for installation of SODK.

Consumables for installation of SODK.

1.5. Signal conductors are designed to transmit current or high-frequency pulses from control devices in order to determine the condition of the pipeline.

1.6. The cable is designed to connect signal conductors located in the PPU-insulation of the pipeline with terminals at control points.

1.7. The terminals are designed for connecting monitoring devices and connecting signal conductors (cables) at monitoring points.

1.8. The detectors are designed to determine the state of pipeline insulation and the integrity of signal conductors.

1.9. The locators are designed to search for places where pipeline insulation is wet and where signal conductors are damaged.

1.10. The control and installation tester is designed to check the insulation condition (measurement of insulation resistance Riz.) and the integrity of the conductors of the control system (measurement of the resistance of signal conductors Rpr.) of both individual pipeline elements and an installed and ready-for-use pipeline.

1.11. The carpet (vandal-proof metal “cabinet”) is designed to install terminals in it and protect the elements of the UEC system from environmental influences and unauthorized access.

1.12. Tools and consumables are designed for high-tech connection of signal conductors, cable connections, terminals and detectors.

1.13. Control point - a designated and equipped access point to the UEC system provided by the project.

1.14. Signal line is the main or transit signal conductor of the pipeline system between the starting and ending control points.

1.15. Signal circuit – two signal conductors of the pipeline UEC system between the initial and final control points, combined into a single electrical circuit.

1.16. The performance assessment of the SDSK is carried out using a control and installation tester, by measuring the actual values ​​of insulation resistance and resistance of signal conductors and then comparing them with the values ​​calculated according to the standards (see. clause 5.4. ÷ 5.7.).

1.17. By agreement with the operating organization, the use of other UEC systems is allowed, the installation, control and configuration of which must be carried out in accordance with the relevant technical documentation of the manufacturer.

2. Technical requirements

2.1. Thermal insulation of steel pipes, fittings and parts must have at least two linear signal conductors of the UEC system. The signal conductors should be placed at a distance of 20 ± 2 mm from the surface of the steel pipe and geometrically at 3 and 9 o'clock.

2.2. For pipelines with a metal pipe diameter of 530 mm and above, it is recommended to install three conductors. The third wire is called the reserve wire; the pipe is oriented in the trench so that it is located at the top of the pipe at 12 o'clock.

2.3. A wire made of MM 1.5 copper wire (cross-section 1.5 mm2, diameter 1.39 mm) is used as a signal conductor.

2.4. The electrical resistance of signal conductors made from MM 1.5 wire should be in the range of 0.010÷0.017 Ohm per 1 running meter of wire (at temperatures from −15 to +150ºС).

2.5. The use of conductors in insulating braiding (except for flexible steel pipelines) and varnished wires is prohibited.

2.6. Signal conductors must be led out of the pipeline through the end and intermediate elements of the pipeline with the output cable. The design and manufacturing technology of the pipeline element with cable outlet must ensure tightness throughout the entire service life of the pipeline. To manufacture the above elements, it is recommended to use a special product - welded (welded) cable terminals with pre-soldered cable.

2.7. One of the conductors must be marked. The marked conductor is called the main conductor, and the unmarked conductor is called transit. Marking of the conductor is carried out either by tinning the entire conductor (before installing it in the pipe), or by painting with paint the parts of one conductor protruding from the insulation on both sides of the pipe.

2.8. The reserve wire is intended to be used in place of one of the other two wires if they are damaged. Reserve wires at pipeline joints must be connected to each other throughout the entire length of the pipeline. Do not remove the reserve wire in the end and intermediate elements of the pipeline with the output cable from under the insulation.

2.9. In flexible steel pipelines, insulated copper wires woven into a single bundle are used as signal conductors.

2.10. Marking of conductors for flexible steel pipelines according to the manufacturer's instructions:

A wire in a white moisture-permeable sheath with a cross-section of 0.8 mm2 (electrical resistance should be in the range of 0.019÷0.032 Ohm per 1 linear meter at t = −15÷150ºС) performs the function of the main signal wire;

A wire in a green moisture-proof sheath with a cross-section of 1.0 mm2 (electrical resistance should be in the range of 0.015÷0.026 Ohm per 1 linear meter at t = −15÷150ºС) performs the function of a transit wire.

2.11. The UDC system for flexible pre-insulated steel pipelines is compatible with the UDC system for pre-insulated rigid steel pipelines. Combination is possible through the terminal.

2.12. The flexible steel piping system uses the same instrumentation and equipment that is used for rigid pre-insulated steel piping.

2.13. Terminals must be used to connect signal conductors and connect monitoring devices. Types of terminals, their purpose and symbols are indicated in Appendix No. 1.

2.14. Installation of terminals with external connectors and environmental protection class IP54 and lower in rooms with high humidity (thermal chambers, basements of houses with a risk of flooding, etc.) is prohibited.

2.15. At control points with high air humidity, it is necessary to use terminals with protection class IP65 and higher. If at this point it is necessary to use a terminal with external connectors to connect the detector, then it is recommended to use terminals with sealed external connectors.

2.16. In order to comply with the rules for the design and installation of signal conductors on pipeline branches ( pp. 3.8., 3.9., 4.14.) it is recommended to use tees with a universal conductor arrangement (see. Application), which allows you to use one standard tee for branches on both the right and left sides.

2.17. At control points and transits in chambers and basements of houses, cables of the NYY or NYM brand (3x1.5 and 5x1.5) with a conductor cross-section of 1.5 mm2 and color marking of the cores are used as connecting cables.

2.18. At control points, connecting cables must be connected to signal conductors only through sealed cable terminals of the end and intermediate elements of the pipeline.

2.19. To extend the cable to the design or required length, it is recommended to use ready-made cable extension kits: for a three-core cable - the KUK-3 kit and for a five-core cable - the KUK-5 kit, which provide for the use of sets of heat-shrinkable tubes with an internal adhesive layer.

2.20. Connection of NYM 3x1.5 cable cores at control end points with signal conductors in insulated pipe must be produced in accordance with the color markings (see. Appendix, table 2).

2.21. The connection of NYM 5x1.5 cable cores at intermediate control points with signal conductors in an insulated pipe must be made in accordance with the color marking (see. Appendix, table 3).

2.22. Contact of the yellow-green conductor with the steel pipeline "grounding" must be ensured using a detachable threaded connection(a nut with a washer on a bolt welded to a steel pipeline).

2.23. To ensure continuous monitoring of the condition of the pipeline insulation, control should be carried out (and provided for in projects on ODS) using stationary monitoring devices equipped with visual or audio alarms. If it is impossible to connect stationary devices (due to lack of 220V power supply or due to the impossibility of ensuring the safety of the equipment), it is recommended to use a portable detector with autonomous power supply. A portable detector allows for periodic monitoring.

2.24. Technical specifications The detectors used must be unified:

The threshold value of insulation resistance (Riz.) for triggering the “wet” signal must be in the range from 1 to 5 kOhm.

The threshold value of the signal conductor resistance (Rpr.) to trigger a “break” signal must be in the range of 150 ÷ ​​200 Ohm ±10%.

2.25. In stationary detectors, electrical isolation between channels must be implemented, which ensures that there is no mutual influence of their readings.

2.26. In order to increase the information content of pipeline condition monitoring, the use of multi-level damage detectors is recommended. The presence of several levels of insulation resistance indication in the detector allows you to control the rate of insulation wetting, which characterizes the danger of a defect.

2.27. To ensure constant monitoring, increase the efficiency of eliminating defects and reduce operating costs, it is recommended to use stationary devices with the ability to connect to dispatch systems.

2.28. A dispatch system is a system for collecting data from objects at different distances to a single dispatch center, communication between which is carried out:

Via dedicated or switched cable lines;

Via GSM connection;

By radio channel.

2.29. Dispatch systems must implement the following functions:

24-hour monitoring of the state of objects and parameter values;

Selection and archiving of parameters with the ability to plot graphs;

Notification of system failures via SMS and email.

2.30. The basis of the data transmission equipment installed in heating point, is a multi-function controller. A controller is a hardware device designed to collect information, process it initially and transmit it to the control center. Stationary pipeline condition detectors with polyurethane foam insulation are connected to the controller input module. Data received from connected devices is transmitted to the control center via the selected communication channel ( cable line, GSM - communication, radio channel), where they are processed, visualized, archived and stored. In case of emergency situations, the signal from the controller in real-time mode is transmitted to the control center.

2.31. Basic way data transfer from the detector to the controllers are “Dry Contact” and “Current Output” connections, which are applicable in all existing systems dispatching.

2.32. Determining the location of a fault in the UEC system (moistening or breakage of the signal conductor) is carried out by a fault locator, which is a portable pulse reflectometer.

2.33. The locator used to determine the location of pipeline damage must have the following characteristics:

Provide the ability to determine the type and location of defects with an error of no more than 1% of the measured length of the signal conductor;

Range (range) of measurements is not less than 100 m;

Internal memory for recording measurement results with a volume that allows you to record and store at least 20 reflectograms;

Function for exchanging information with a personal computer (it is possible to use the reflectometer with a portable printing device).

2.34. Checking the insulation condition of pipeline elements should be carried out with a high-voltage megohmmeter (control and installation tester) with a test voltage of 500V. The standard insulation resistance of one element 10 m long must be at least 30 MOhm.

2.35. Checking the integrity of signal conductors should be carried out with a tester that has the function of measuring conductor resistance, or using a digital multimeter.

2.36. To reduce operator errors when working with the tester, it is recommended to use testers with digital display of the values ​​of the measured parameters.

2.37. The tester must have the function of switching (selecting) the control voltage: 250 and 500V.

2.38. The design of the carpet must meet the following requirements:

Ensure the safety of the equipment located in it;

Ensure ease of maintenance and operation of the SDS;

Eliminate the formation of condensation on the terminal elements and the penetration of moisture;

2.45. Signal conductors, detectors, terminals, locators (reflectometers), testers and cables used to monitor the condition of the pipeline must have the necessary certificates (conformity, measuring instruments, etc.) and comply with regulatory documentation.

3. SODK design

3.1. Mandatory integral part The heating network project made from pre-insulated pipes is a project for the UEC system.

3.2. The project for the UEC system is developed on the basis of the technical specifications from the operating organization and the project for laying pipelines, as well as this Standard and Manufacturers' Instructions from manufacturers of equipment for control systems. The technical specifications must indicate the installation location of stationary monitoring devices and other special requirements.

3.3. The project for the UEC system must contain: an explanatory note, a graphic representation of the control system diagram, and electrical connection diagrams.

3.4. IN explanatory note the choice of terminals and control devices - damage detectors - must be justified, the locations of control points and their equipment must be justified and determined, and consumables must be calculated. The note must contain a table of characteristic points, a table of control points, and a table of cable markings. Sample tables are provided in Appendix No. 4.

3.5. The graphical diagram of the control system must contain the following data:

Characteristic points of the pipeline (pipeline turning angles, branches, fixed supports, shut-off valves, compensators, diameter transitions, pipeline ends, control points), corresponding to the route plan;

Control points;

Table symbols all used SODC elements.

3.6. Based on the results of project development, a specification for control system components and consumables should be drawn up, indicating installation points.

3.7. The electrical connection diagram must show the order of connecting connecting cables to the terminals (switching conductors inside the terminal) and the order of connecting cables to the signal conductors of the pipeline. The order of connecting cable conductors inside the terminal must be indicated in the passport for the connected terminal and taken as a basis when drawing up electrical diagram. The order of connecting cables to the pipeline signal conductors is indicated for each cable type in Appendix No. 3.

3.8. The wire located on the right in the direction of water supply to the consumer on both pipelines is used as the main signal wire - on the SODK diagrams, during design, it is indicated by a dotted line. The second signal conductor is a transit conductor - indicated in the diagrams by a solid line.

3.9. All side branches must be included in the break of the main signal wire. It is prohibited to connect side branches to the copper wire located on the left along the water supply to the consumer (transit).

3.10. The design of UEC systems must be carried out with the possibility of connecting the designed system to existing systems UEC and planned in the future.

3.11. The control point includes: a pipeline element with a cable outlet, a cable, a terminal and, if necessary, a carpet and a detector.

3.12. The choice of damage detectors (portable or stationary) should be based on the ability to provide continuous monitoring (see. clause 2.23, clause 2.26, clause 2.27). The type of stationary detector (two- or four-channel) depends on the number of pipelines of the designed heating main. Quantity stationary detectors is determined by the correspondence of the length of the designed pipeline with the range of action of the selected detector. No more than one stationary detector should be installed on each signal circuit of the designed heating network.

3.13. The choice of one or another type of terminal depends on the purpose of the control point at which the terminal is to be installed (see. Application).

3.14. At the ends of the heating network, it is necessary to install end control points where end terminals , one of which may have an output to a stationary detector.

3.15. At the end of the pipeline where there is no control point, the signal conductors must be looped into the end element under a metal insulation plug.

3.16. At the border of adjacent heating network projects at the points of their connection, including those intended for the future, it is necessary to provide control points and install one terminal , allowing both the combination and separation of the UEC system of these sections.

3.17. Intermediate control points must be provided at a distance of no more than 300 m (along the length of the signal line) from the nearest control point.

3.18. At intermediate control points, intermediate terminals .

3.19. To increase the reliability of the UEC system, it is recommended to install terminals with protection class IP 65 and higher at intermediate control points.

3.20. For a pipeline section longer than 40 meters, it is necessary to install control points on both sides of the section: the end and intermediate control points.

3.21. At the beginning of side branches longer than 40 m, it is necessary to arrange an intermediate control point where intermediate terminal regardless of the location of other control points on the main pipeline.

3.22. The rule specified in clause 3.21 does not apply to the case when a lateral branch of the pipeline occurs in a thermal chamber in which the pipeline will be laid without the UEC system. In this case, an intermediate control point is not provided, but only a control point is installed in the chamber on the branch (see. clause 3.25 ÷ 3.28).

3.23. For side branches less than 40 meters long, it is allowed to install one control point: either an intermediate control point at the beginning of the branch or an end control point at the end of the branch. The choice of location for the control point is determined in agreement with the operating organization.

3.24. If it is necessary to install cables longer than 10 m at control points, you should install an additional control point with installation in it walk-through terminal as close to the pipeline as possible.

3.25. In thermal chambers (and other similar objects), where the designed pipeline will be laid without a monitoring system, it is necessary to provide end monitoring points and install walk-through terminal .

3.26. In thermal chambers (and other similar objects), where the designed pipeline will be laid without a control system (due to the lack of pre-insulated pipeline elements), it is necessary to install pipeline end elements with a sealed cable outlet and a metal insulation plug.

3.27. When connecting conductors of the UEC system in series at the end of the insulation (passage of pipelines through thermal chambers, basements of buildings, etc.), the conductor connections must be made using a cable (or cable extension kits) and only through walk-through terminals .

3.28. In thermal chambers (and other similar objects), where the designed pipeline will be laid without a control system and branches in 3 or 4 directions, it is necessary to provide end control points and install walk-through terminal .

3.29. To increase the reliability of the UEC system, it is recommended to install pass-through terminals with a protection class of IP 65 and higher.

3.30. The choice of the type of cable used depends on the type of monitoring point: a five-core cable is used at intermediate points, and a three-core cable is used at the end points.

3.31. Transit cables connecting terminals can be of arbitrary length. The total length of the signal circuit with the transit cable should not exceed the operating range of the detectors.

3.32. Installation of terminals at intermediate and end control points is carried out in ground (KNZ) or wall (KNS) carpets. The design of the carpet is regulated terms of reference. At the end points of the pipeline, it is allowed to install terminals in central heating stations, boiler rooms and other similar facilities without carpets.

3.33. Installation of underground carpets without proper sealing of the carpet is prohibited.

3.34. The amount of consumables for installing the UEC system is calculated based on consumption rates. Consumption rates are indicated in Appendix No. 5.

4. Installation of SODK

4.1. Installation of the UEC system must be carried out in accordance with the diagram developed in the project and agreed with the operating organization.

4.2. Installation of ODS must be carried out by specialists who have been trained at the training centers of equipment manufacturers for control systems and pre-insulated pipes.

4.3. Installation of the ODS consists of connecting signal conductors at pipeline joints, connecting the cable to “pipeline elements with an output cable,” installing carpets, connecting terminals to the cable, and connecting a stationary detector.

4.4. Work on installing the UEC system, connecting signal conductors at pipeline joints, and extending cables should be carried out in accordance with the technological instructions of the manufacturer or supplier of components for the UEC system and using special tools and installation kits.

4.5. It is necessary to check the insulation condition and integrity of the signal wires of the UEC system before starting installation of the pipeline. The performance assessment of the SDSK is carried out in accordance with clause 5.4. ÷ 5.7. The purpose of the inspection before installation of the pipeline is to detect defects that could have formed during transportation, storage and loading and unloading operations. Each pipeline element must be inspected.

4.6. When installing pipelines, the pipeline elements must be oriented in such a way that the main signal conductor is always located to the right in the direction of movement of the coolant to the consumer, both along the supply and return pipelines.

4.7. When installing pipelines, pipeline elements must be oriented in such a way that the location of the conductors is in the upper part of the joint, excluding the lower quarter.

4.8. The installation of the pipeline element with the output cable must be carried out taking into account the direction of supply of the coolant in the supply pipeline. The control arrow on the shell must coincide with the direction of coolant supply to the consumer. On the return pipe, the installation of the pipeline element with the output cable is carried out in the direction of the coolant supply of the direct pipe.

4.9. Installation of signal conductors should be carried out after welding the steel pipe.

4.10. Protect conductors during welding. Before using SODK devices, make sure that welding work on the pipeline is completed.

4.11. Before connecting conductors at the joints of a welded pipeline, it is necessary to check the functionality of the control system at each joint in accordance with clause 5.4. ÷ 5.7..

4.12. Connect the signal conductors at the joints in a strictly specified order: connect the main signal wire to the main one, and connect the transit wire to the transit wire. Overlapping of conductors at the junction is prohibited.

4.13. It is recommended to connect the reserve conductor used in pipelines with a diameter of 530 mm or more at pipeline joints, but not remove it from the insulation, since it is not involved in the operation of the SODC system.

4.14. All side branches of the pipeline must be included in the break of the main signal wire (see. Application). It is prohibited to connect side branches to the transit wire.

4.15. When insulating joints, signal conductors of adjacent pipeline elements must be connected using copper crimp bushings with mandatory subsequent soldering of the junction of the conductors.

4.16. Crimping of bushings should only be done using special crimping pliers. It is prohibited to crimp the bushings with pliers or other similar tools.

4.17. Soldering of conductors is carried out using a portable gas soldering iron with replaceable or refillable gas cylinders or an electric soldering iron.

4.18. Solder conductors using only inactive flux and solder.

4.19. Signal conductors connected at pipeline joints must be fixed in special holders (racks for fastening conductors) - at least 2 pieces per conductor.

4.20. Attach conductor holders at joints to metal pipe using fastening tape. It is prohibited to secure the holders with PVC insulating tape. It is prohibited to attach the holders to the pipe over the conductor installed in them.

4.21. Upon completion of insulation of joints along the entire length of the pipeline or in sections, the performance of the SDSK is assessed in accordance with clause 5.4. ÷ 5.7.

4.22. After completing the installation of butt joints, it is necessary to arrange control points and equip them with equipment in accordance with the project specifications.

4.23. Pipeline connecting cables must be marked to identify the associated pipes and cables. It is recommended to indicate the following data in the marking: the number of the characteristic point where the cable is connected, the number of the characteristic point towards which the signal conductors along this cable are directed and its actual length.

4.24. The connecting cables must be connected to the signal conductors through sealed cable terminals using heat shrink tubing sets with an internal adhesive layer.

4.25. The connection of cable cores at control points with signal conductors in an insulated pipe must be made in accordance with the color marking (see. Application).

4.26. The connecting cable from the pipeline with a sealed cable outlet to the carpet must be laid in a galvanized pipe with a diameter of 50 mm. Welding (soldering) of a protective galvanized pipe with a cable laid in it is prohibited.

4.27. Laying the connecting cable inside buildings (structures) to the installation site of the terminals or at the point where the thermal insulation is broken (in a thermal chamber, etc.) must also be carried out in a galvanized pipe with a diameter of 50 mm, secured to the wall with brackets. Inside buildings, the use of protective corrugated hoses is allowed.

4.28. The connection of connecting cables to the terminals at control points must be carried out in accordance with the color markings and operating instructions (device passport) attached to each terminal. The cable length must allow the terminal to be removed for measurements and repairs.

4.29. Installation of terminals must be carried out in accordance with the operating instructions (device passport) attached to each terminal.

4.30. Terminals must be equipped with tags (aluminum or plastic) with markings indicating the direction of measurement according to clause 4.23.

4.31. Installation of stationary detectors and their connection to the terminals must be carried out in accordance with the operating instructions (device passport) attached to each detector.

4.32. The locations for attaching detectors at control points to the wall must be agreed upon with the operating organization.

4.33. The portable damage detector and pulse reflectometer (locator) are not permanently installed on the route, but are connected to the UEC system as needed and in accordance with the operating rules.

4.34. Each carpet must be marked after installation. Marking should be applied in accordance with the requirements of the operating organization. The marking indicates the number of the characteristic point at which it is installed and the project number.

4.35. After installing the UEC system, its executive diagram should be completed, including:

Graphic representation of the location and connection of pipeline signal conductors;

Designation of the locations of building and installation structures related to the pipeline being designed (houses, central heating substations, chambers, etc.);

Locations of characteristic points;

Table of characteristic points;

Table of symbols of all used SODC elements;

Table of markings for connecting cables or terminals;

Specification of the devices and materials used.

4.36. Upon completion of installation of the UEC system (work in accordance with clause 4.3.) an examination should be carried out, including:

Measurement of insulation resistance for each signal conductor (signal line resistance);

Measuring loop resistance of signal conductors (signal loop resistance);

Measuring the length of signal conductors and the lengths of connecting cables at all control points;

Recording reflectograms of signal conductors.

All results of changes are entered into the performance certificate of the control system ( Application).

4.37. The operability of the DCS system of individual pipeline elements is checked with a tester with a voltage of 500V, and the pipeline with a fully installed DCS is checked with a voltage of 250V.

4.38. To avoid damage to stationary instruments and distortions in the tester readings, it is necessary to disconnect stationary monitoring devices from the UEC system when taking measurements.

5. Acceptance of SODK into operation

5.1. Acceptance of UEC systems should be carried out by a commission consisting of representatives:

The organization that installed and commissioned the UEC system;

Operating organization;

An organization that monitors the condition of polyurethane foam insulation and the UEC system (if the control is carried out by a third party).

5.2. When accepting the UEC system into operation, the following documentation and equipment must be provided:

Executive diagram of the control system (if the installed diagram of the control system differs from the design one, then all changes must be taken into account in the executive diagram);

Diagram of joints (on the diagram of joints the distance between each joint must be indicated in meters, and characteristic points must also be indicated in accordance with the diagram of the UEC system);

Plan of the heating main on a scale of 1:2000;

Plan of the heating main on a scale of 1:500 with geodetic reference of the SODK carpets;

Letter of guarantee from the construction organization for a period of five years;

Certificate of operability of the control system;

Monitoring devices (damage detectors, locators, etc.) with components (if any) and technical documentation for their operation - according to the project;