Double-layer corrugated HDPE pipes

Double-layer corrugated HDPE pipes are double-layer corrugated pipes made of polyethylene low pressure(PND). Double-layer corrugated HDPE pipes are pipes with a two-layer wall, where the outer wall of the pipe has a corrugated surface, and the inner wall of the pipe has a smooth polypropylene (PP) surface. Double-layer corrugated pipes have a special molded rubber ring made of ethylene-propylene rubber (EPDM), which is designed to seal the pipe joints. Corrugated HDPE pipes are produced in two types: corrugated pipe with a socket and a corrugated pipe without a socket. The socket on a corrugated pipe is formed by injection molding, which ensures the strength of the socket and the reliability of the pipe connection. Double-layer corrugated HDPE pipes are produced with a nominal diameter from 250 to 1000 mm, and a pipe length of 6 m (excluding the length of the socket).

Features and Benefits

• are highly resistant to chemical and aggressive environments
• have corrosion resistance and resistance to water jet wear
• are resistant to both high temperatures up to +100 0C and low temperatures
• not affected by stray currents, not electrically conductive
• have elasticity and stretchability
• have an internal smooth adhesive surface, which ensures high throughput
• ensure tightness of connections during repeated freezing of water inside the pipe
• can withstand pressure surges inside the pipeline up to 0.25 MPa
• have a stable corrugation profile with high geometric rigidity, which ensures high overall ring stiffness of the pipe up to SN12
• are reliable in case of subsidence or soil movement
• are light in weight, easy to transport, cut and repair
• easy to install and dismantle pipes, and their further disposal
• durable, service life of at least 50 years

Areas of use

Double-layer corrugated HDPE pipes are intended for external networks and collectors of household and storm sewer, and are used for the installation of pipelines in sewerage systems that have large flow sections. Also, double-layer corrugated polyethylene pipes are widely used for constructing culverts. pipeline systems under bridges and dams, under highways and various communication routes, and for transporting domestic and industrial wastewater. Since these corrugated HDPE pipes have a high ring rigidity of the pipe up to SN12, they can be used for laying various engineering communications, which pass in places with a large load on the ground.

Transportation, storage and installation of double-layer corrugated pipes does not require special skills and special equipment and equipment, since these pipes are light in weight. Double-layer corrugated polyethylene pipes are connected to each other using a coupling and a socket; the pipe to be connected is inserted inside the coupling or socket to a depth of up to 3 profile steps, this will ensure the alignment of the connected pipes and the tightness of the connection. With pipes made of other materials, these corrugated pipes are connected using special connecting transitions: transition to PVC pipes, transition to HDPE pipes, transition with a flange, for flange connection with cast iron tubes, steel pipes and others metal pipes. Double-layer corrugated HDPE pipes can be connected to various types plastic and reinforced concrete wells.

Transitions for double-layer corrugated pipe: transition to PE pipe and transition to flange connection

Technical characteristics of double-layer corrugated HDPE pipes

Double-layer corrugated pipe with socket

Nominal pipe diameter, mm	Interior diameter d 1, mm	Outer diameter d 2, mm	Length pipes l 1, mm	Length bell l 2, mm	Length pipes l 1 with bell l 2, mm

Double-layer corrugated pipe without socket

Nominal pipe diameter, mm	Interior diameter d 1, mm	Outer diameter d 2, mm	Length pipes l 1, mm

KORSIS pipes can be connected to pipes of any other type using fittings specially designed for this (Fig. 15).

Let's look at an example of the most common type of connection with PVC/PP pipes (Fig. 16).

To perform this type of connection, the following procedure is proposed:

• Inspect and clean the PVC pipe socket, coupling and free end of the KORSIS pipe.
• Insert the free end of the KORSIS pipe into the socket of the coupling, having previously treated its internal surface with silicone grease.
• Lubricate the seal in the socket with grease. Insert the bell-socket end of the coupling into the socket of the PVC pipe.

The most preferred method of transition between existing system and the new line of KORSIS pipes is the use of manholes.

Rice. 15. Transition from welded KORSIS SN8 to PE 80 SDR 13.6

An inspection well is an independent structure that is part of the sewer system. Can be polyethylene or concrete. There are two types of polyethylene wells. The first type consists of a cast base (pot) and a vertical pipe KORSIS (well heat). To connect a pipe to such a well, special rubber sealing rings are used to ensure water-tightness of the connection (Fig. 17, 19).

The first type is a structure welded from sections of KORSIS pipe. It is obvious that such wells can be maximally adapted to customer requirements. The connection of this type of manhole to the pipe is usually made using a coupling (Fig. 18). Connected pipes CORSIS with a concrete manhole is carried out by fixing the pipe in the well using cement mortar. The design feature of KORSMS pipes - a special profile - ensures the reliability and tightness of such a connection (Fig. 20). You should pay attention to the fact that the heating agent in the well has a diameter as close as possible to the outer diameter of the pipe. All cracks that form must be filled cement mortar, which must meet the requirements for ensuring the density of the concrete connection. When installing a pipe in a concrete or reinforced concrete well wall, it is necessary to provide rigid support for the free end of the pipe by adding soil until the concrete sets completely.

The KORSIS pipe should not be concreted simultaneously with the construction of the walls. monolithic well, because this can cause deformation of the pipe under the weight of uncured concrete.

Fig. 16. Connection of KORSIS pipes (smooth end) with PVC/PP pipes


Rice. 17, PE well complete with standard tray

When installing a socketless section of KORSIS pipe in a concrete or reinforced concrete well, it is necessary to take into account that the length of the section of pipe that is located with outside well, must be at least half the diameter of the pipe (Fig. 21).

The free end of the pipe prepared in this way is put on coupling KORSIS, into which the next section of the pipeline is inserted.

The diameter of the pipe inserted into a concrete well should not exceed half the diameter of the well.

This technical solution It has whole line advantages:

• possibility to use on construction site remaining unmeasured pipe sections;
• ribbed shape outer surface KORSIS pipes make it easier to fasten and stabilize the position of the pipe in the concrete wall of the well;
• This method also makes it possible to compensate for stresses that arise as a result of possible uneven shrinkage concrete well and pipeline;
• quick and easy installation.

Pipe connectionCORSISbutt welding

One of the advantages of the KORSIS system is the ability to connect pipes by butt welding. This possibility is ensured by the sufficient thickness of the pipe wall e^ between the ribs and the width of the profile.

The same welding methods and welding equipment are used as for conventional pressure polyethylene pipes. Suppliers of welding equipment, along with the equipment, provide a table of values ​​of recommended welding parameters - temperature, time and pressure. For butt verification of rough CORSIS, the values ​​​​for welding pressure polyethylene pipes with small wall thickness are usually taken. Care must be taken to avoid contact of the heater with the corrugation ribs.

The standard welding cycle for a KORSIS pipe includes the following sequence of operations with certain time regulations (Table 15)

Resistance to internal pressure

Sewage pipes are considered free-flow, but at the same time, according to)