Sometimes it is very important to accurately calculate the volume of water passing through the pipe. For example, when you need to design new system heating. This raises the question: how to calculate the volume of a pipe? This indicator helps to choose the right equipment, for example, size expansion tank. In addition, this indicator is very important when antifreeze is used. It is usually sold in several forms:

• Diluted;
• Undiluted.

The first type can withstand temperatures of 65 degrees. The second one will freeze at -30 degrees. To buy required quantity antifreeze, you need to know the volume of coolant. In other words, if the volume of liquid is 70 liters, then you can purchase 35 liters of undiluted liquid. It is enough to dilute them, maintaining a proportion of 50–50, and you will get the same 70 liters.

To get accurate data, you need to prepare:

• Calculator;
• Calipers;
• Ruler.

First, the radius is measured, designated by the letter R. It can be:

• Internal;
• External.

The outer radius is necessary to determine the size of the space it will occupy.

To calculate, you need to know the pipe diameter data. It is denoted by the letter D and is calculated using the formula R x 2. The circumference is also determined. Denoted by the letter L.

To calculate the volume of a pipe measured cubic meters(m3), you must first calculate its area.

To obtain an accurate value, you must first calculate the cross-sectional area.
To do this, use the formula:

• S = R x Pi.
• The required area is S;
• Pipe radius – R;
• Pi number is 3.14159265.

The resulting value must be multiplied by the length of the pipeline.

How to find the volume of a pipe using the formula? You only need to know 2 values. The calculation formula itself has the following form:

• V = S x L
• Pipe volume – V;
• Sectional area – S;
• Length – L

For example, we have a metal pipe with a diameter of 0.5 meters and a length of two meters. To carry out the calculation, the size of the outer cross member of the stainless metal is inserted into the formula for calculating the area of ​​the circle. The pipe area will be equal to;

S= (D/2) = 3.14 x (0.5/2) = 0.0625 sq. meters.

The final calculation formula will take the following form:

V = HS = 2 x 0.0625 = 0.125 cu. meters.

This formula calculates the volume of absolutely any pipe. And it doesn’t matter at all what material it is made of. If the pipeline has many components, using this formula, you can calculate separately the volume of each section.

When performing calculations, it is very important that the dimensions are expressed in the same units of measurement. The easiest way to calculate is if all values ​​are converted to square centimeters.

If you use different units of measurement, you can get very questionable results. They will be very far from the real values. When performing constant daily calculations, you can use the calculator's memory by setting a constant value. For example, Pi multiplied by two. This will help calculate the pipe volume much faster different diameters.

Today, you can use ready-made computer programs, which indicate in advance standard parameters. To perform the calculation, you will only need to enter additional variable values.

Download the program https://yadi.sk/d/_1ZA9Mmf3AJKXy

How to calculate cross-sectional area

If the pipe is round, the cross-sectional area should be calculated using the formula for the area of ​​a circle: S = π*R2. Where R is the radius (internal), π - 3.14. In total, you need to square the radius and multiply it by 3.14.
For example, the cross-sectional area of ​​a pipe with a diameter of 90 mm. We find the radius - 90 mm / 2 = 45 mm. In centimeters this is 4.5 cm. We square it: 4.5 * 4.5 = 2.025 cm2, substitute it into the formula S = 2 * 20.25 cm2 = 40.5 cm2.

The cross-sectional area of ​​a profiled product is calculated using the formula for the area of ​​a rectangle: S = a * b, where a and b are the lengths of the sides of the rectangle. If we consider the cross-section of the profile to be 40 x 50 mm, we get S = 40 mm * 50 mm = 2000 mm2 or 20 cm2 or 0.002 m2.

Calculation of the volume of water in the entire system

To determine such a parameter, it is necessary to substitute the value of the internal radius into the formula. However, a problem immediately appears. How to calculate the total volume of water in the pipe of the entire heating system, which includes:

• Radiators;
• Expansion tank;
• Heating boiler.

First, the volume of the radiator is calculated. To do this, it opens technical certificate and the volume values ​​of one section are written down. This parameter is multiplied by the number of sections in a particular battery. For example, one is equal to 1.5 liters.

When installed bimetallic radiator, this value is much smaller. The amount of water in the boiler can be found in the device data sheet.

To determine the volume expansion tank, it is filled with a pre-measured amount of liquid.

The volume of pipes is determined very simply. The available data for one meter of a certain diameter simply needs to be multiplied by the length of the entire pipeline.

Note that in the global network and reference literature, you can see special tables. They show approximate product data. The error in the given data is quite small, so the values ​​given in the table can be safely used to calculate the volume of water.

It must be said that when calculating values, you need to take into account some characteristic differences. Metal pipes having large diameter, pass the amount of water significantly less than the same polypropylene pipes.

The reason lies in the smoothness of the surface of the pipes. For steel products it is made with great roughness. PPR pipes do not have roughness on the inner walls. However, steel products have a larger volume of water than other pipes of the same cross-section. Therefore, to make sure that the calculation of the volume of water in the pipes is correct, you need to double-check all the data several times and confirm the result with an online calculator.

Internal volume of a linear meter of pipe in liters - table

The table shows the internal volume of a linear meter of pipe in liters. That is, how much water, antifreeze or other liquid (coolant) is needed to fill the pipeline. taken inner diameter pipes from 4 to 1000 mm.

Inner diameter, mm	Internal volume of 1 m running pipe, liters	Internal volume of 10 m linear pipes, liters
4	0.0126	0.1257
5	0.0196	0.1963
6	0.0283	0.2827
7	0.0385	0.3848
8	0.0503	0.5027
9	0.0636	0.6362
10	0.0785	0.7854
11	0.095	0.9503
12	0.1131	1.131
13	0.1327	1.3273
14	0.1539	1.5394
15	0.1767	1.7671
16	0.2011	2.0106
17	0.227	2.2698
18	0.2545	2.5447
19	0.2835	2.8353
20	0.3142	3.1416
21	0.3464	3.4636
22	0.3801	3.8013
23	0.4155	4.1548
24	0.4524	4.5239
26	0.5309	5.3093
28	0.6158	6.1575
30	0.7069	7.0686
32	0.8042	8.0425
34	0.9079	9.0792
36	1.0179	10.1788
38	1.1341	11.3411
40	1.2566	12.5664
42	1.3854	13.8544
44	1.5205	15.2053
46	1.6619	16.619
48	1.8096	18.0956
50	1.9635	19.635
52	2.1237	21.2372
54	2.2902	22.9022
56	2.463	24.6301
58	2.6421	26.4208
60	2.8274	28.2743
62	3.0191	30.1907
64	3.217	32.1699
66	3.4212	34.2119
68	3.6317	36.3168
70	3.8485	38.4845
72	4.0715	40.715
74	4.3008	43.0084
76	4.5365	45.3646
78	4.7784	47.7836
80	5.0265	50.2655
82	5.281	52.8102
84	5.5418	55.4177
86	5.8088	58.088
88	6.0821	60.8212
90	6.3617	63.6173
92	6.6476	66.4761
94	6.9398	69.3978
96	7.2382	72.3823
98	7.543	75.4296
100	7.854	78.5398
105	8.659	86.5901
110	9.5033	95.0332
115	10.3869	103.8689
120	11.3097	113.0973
125	12.2718	122.7185
130	13.2732	132.7323
135	14.3139	143.1388
140	15.3938	153.938
145	16.513	165.13
150	17.6715	176.7146
160	20.1062	201.0619
170	22.698	226.9801
180	25.4469	254.469
190	28.3529	283.5287
200	31.4159	314.1593
210	34.6361	346.3606
220	38.0133	380.1327
230	41.5476	415.4756
240	45.2389	452.3893
250	49.0874	490.8739
260	53.0929	530.9292
270	57.2555	572.5553
280	61.5752	615.7522
290	66.052	660.5199
300	70.6858	706.8583
320	80.4248	804.2477
340	90.792	907.9203
360	101.7876	1017.876
380	113.4115	1134.1149
400	125.6637	1256.6371
420	138.5442	1385.4424
440	152.0531	1520.5308
460	166.1903	1661.9025
480	180.9557	1809.5574
500	196.3495	1963.4954
520	212.3717	2123.7166
540	229.0221	2290.221
560	246.3009	2463.0086
580	264.2079	2642.0794
600	282.7433	2827.4334
620	301.9071	3019.0705
640	321.6991	3216.9909
660	342.1194	3421.1944
680	363.1681	3631.6811
700	384.8451	3848.451
720	407.1504	4071.5041
740	430.084	4300.8403
760	453.646	4536.4598
780	477.8362	4778.3624
800	502.6548	5026.5482
820	528.1017	5281.0173
840	554.1769	5541.7694
860	580.8805	5808.8048
880	608.2123	6082.1234
900	636.1725	6361.7251
920	664.761	6647.6101
940	693.9778	6939.7782
960	723.8229	7238.2295
980	754.2964	7542.964
1000	785.3982	7853.9816

If you have a specific design or pipe, then the formula above shows how to calculate the exact data for the correct flow of water or other coolant.

Online calculation

http://mozgan.ru/Geometry/VolumeCylinder

Conclusion

To pick up exact figure consumption of coolant in your system, you will have to sit for a while. Either search on the Internet or use the calculator that we recommend. Perhaps he can save you time.

If you have a water-type system, then you shouldn’t bother with precise selection of the volume. It is enough to estimate approximately. An accurate calculation is needed more in order not to buy too much and minimize costs. Since many people choose an expensive coolant.

This characteristic depends on several factors. First of all, this is the diameter of the pipe, as well as the type of liquid, and other indicators.

For hydraulic calculation pipeline, you can use the hydraulic pipeline calculation calculator.

When calculating any systems based on fluid circulation through pipes, there is a need to accurately determine pipe capacity. This is a metric value that characterizes the amount of liquid flowing through pipes over a certain period of time. This indicator is directly related to the material from which the pipes are made.

If we take, for example, plastic pipes, they differ in almost the same throughput throughout their entire service life. Plastic, unlike metal, is not prone to corrosion, so a gradual increase in deposits is not observed in it.

As for metal pipes, they throughput decreases year after year. Due to the appearance of rust, the material inside the pipes peels off. This leads to surface roughness and the formation of even more plaque. This process occurs especially quickly in hot water pipes.

The following is a table of approximate values, which was created to make it easier to determine the throughput of pipes in apartment wiring. This table does not take into account the reduction in throughput due to the appearance of sedimentary build-ups inside the pipe.

Table of pipe capacity for liquids, gas, water vapor.

Type of liquid	Speed ​​(m/sec)
City water
Water pipeline
Water system central heating
Pressure system water in pipeline line
Hydraulic fluid	up to 12m/sec
Oil pipeline line
Oil in pressure system pipeline lines
Steam in the heating system
Steam central piping system
Steam in a high temperature heating system
Air and gas in central system pipeline

Most often, ordinary water is used as a coolant. The rate of decrease in throughput in pipes depends on its quality. The higher the quality of the coolant, the longer the pipeline made of any material (steel, cast iron, copper or plastic) will last.

Calculation of pipe capacity.

For accurate and professional calculations, you must use the following indicators:

• The material from which pipes and other elements of the system are made;
• Pipe length
• Number of water consumption points (for water supply system)

The most popular calculation methods:

1. Formula. A rather complex formula, which is understandable only to professionals, takes into account several values ​​at once. The main parameters that are taken into account are the material of the pipes (surface roughness) and their slope.

2. Table. This is a simpler way by which anyone can determine the throughput of a pipeline. An example is the engineering table of F. Shevelev, from which you can find out the throughput capacity based on the pipe material.

3. Computer program. One of these programs can be easily found and downloaded on the Internet. It is designed specifically to determine the throughput for pipes of any circuit. In order to find out the value, you need to enter initial data into the program, such as material, pipe length, coolant quality, etc.

It should be said that the latter method, although the most accurate, is not suitable for calculating simple household systems. It is quite complex and requires knowledge of the meanings of the most various indicators. To calculate a simple system in a private house, it is better to use tables.

An example of calculating pipeline capacity.

Pipeline length is an important indicator when calculating throughput. The length of the pipeline has a significant impact on throughput indicators. The greater the distance water travels, the less pressure it creates in the pipes, which means the flow speed decreases.

Here are some examples. Based on tables developed by engineers for these purposes.

Pipe capacity:

• 0.182 t/h with a diameter of 15 mm
• 0.65 t/h with pipe diameter 25 mm
• 4 t/h with a diameter of 50 mm

As can be seen from the examples given, a larger diameter increases the flow rate. If the diameter is doubled, the throughput will also increase. This dependence must be taken into account when installing any liquid system, be it plumbing, drainage or heat supply. This is especially true for heating systems, since in most cases they are closed, and the heat supply in the building depends on the uniform circulation of the liquid.

In some cases, you have to deal with the need to calculate water flow through a pipe. This indicator tells you how much water the pipe can pass, measured in m³/s.

• For organizations that have not installed a water meter, fees are calculated based on pipe trafficability. It is important to know how accurately these data are calculated, for what and at what rate you need to pay. Individuals This does not apply; for them, in the absence of a meter, the number of registered people is multiplied by the water consumption of 1 person according to sanitary standards. This is quite a large volume, and with modern tariffs it is much more profitable to install a meter. In the same way, in our time it is often more profitable to heat the water yourself with a water heater than to pay utility services for their hot water.
• Calculation of pipe patency plays a huge role when designing a house, when connecting communications to the house .

It is important to make sure that each branch of the water supply can receive its share from the main pipe, even during peak water consumption hours. The water supply system was created for comfort, convenience, and to make work easier for people.

If water practically does not reach the residents of the upper floors every evening, what kind of comfort can we talk about? How can you drink tea, wash dishes, bathe? And everyone drinks tea and swims, so the volume of water that the pipe was able to provide was distributed over the lower floors. This problem can play a very bad role in firefighting. If firefighters connect to central pipe, but there is no pressure in it.

Sometimes calculating the water flow through a pipe can be useful if, after repairing the water supply system by unfortunate craftsmen, replacing part of the pipes, the pressure has dropped significantly.

Hydrodynamic calculations are not an easy task; they are usually carried out by qualified specialists. But let’s say you are engaged in private construction, designing your own cozy, spacious house.

How to calculate the water flow through a pipe yourself?

It would seem that it is enough to know the diameter of the pipe hole to obtain, perhaps rounded, but generally fair figures. Alas, this is very little. Other factors can change the result of calculations significantly. What affects the maximum flow of water through a pipe?

1. Pipe section. An obvious factor. A starting point hydrodynamic calculations.
2. Pipe pressure. As pressure increases, more water flows through a pipe with the same cross-section.
3. Bends, turns, changes in diameter, branches slow down the movement of water through the pipe. Different variants to varying degrees.
4. Pipe length. Longer pipes will carry less water per unit of time than shorter pipes. The whole secret is in the force of friction. Just as it delays the movement of objects familiar to us (cars, bicycles, sleds, etc.), the force of friction impedes the flow of water.
5. A pipe with a smaller diameter turns out to have more area contact of water with the surface of the pipe in relation to the volume of water flow. And from each point of contact a friction force appears. Just like in longer pipes, in narrower pipes the speed of water movement becomes slower.
6. Pipe material. It is obvious that the degree of roughness of the material affects the magnitude of the friction force. Modern plastic materials(polypropylene, PVC, metal, etc.) prove to be very slippery compared to traditional steel and allow water to move faster.
7. Pipe service life. Lime deposits and rust greatly impair the throughput of the water supply system. This is the most tricky factor, because the degree of clogging of the pipe, its new internal relief and the coefficient of friction are very difficult to calculate with mathematical accuracy. Fortunately, water flow calculations are most often required for new construction and fresh, previously unused materials. On the other hand, this system will connect to existing communications that have existed for many years. And how will she behave in 10, 20, 50 years? Newest technologies have improved this situation significantly. Plastic pipes do not rust, their surface practically does not deteriorate over time.

Calculation of water flow through a tap

The volume of fluid flowing out is found by multiplying the cross-section of the pipe opening S by the flow rate V. The cross-section is the area of ​​a certain part of a volumetric figure, in this case, the area of ​​a circle. Found by the formula S = πR2. R will be the radius of the pipe opening, not to be confused with the radius of the pipe. π is a constant, the ratio of the circumference of a circle to its diameter, approximately equal to 3.14.

The flow rate is found using Torricelli's formula: . Where g is the acceleration of gravity on planet Earth equal to approximately 9.8 m/s. h is the height of the water column that stands above the hole.

Example

Let us calculate the water flow through a tap with a hole with a diameter of 0.01 m and a column height of 10 m.

Hole cross section = πR2 = 3.14 x 0.012 = 3.14 x 0.0001 = 0.000314 m².

Outflow velocity = √2gh = √2 x 9.8 x 10 = √196 = 14 m/s.

Water flow = SV = 0.000314 x 14 = 0.004396 m³/s.

Converted to liters, it turns out that 4.396 liters per second can flow from a given pipe.

Why are such calculations needed?

When drawing up a plan for the construction of a large cottage with several bathrooms, a private hotel, an organization fire system, it is very important to have more or less accurate information about the transporting capabilities of the existing pipe, taking into account its diameter and pressure in the system. It's all about pressure fluctuations during peak water consumption: such phenomena quite seriously affect the quality of the services provided.

In addition, if the water supply is not equipped with water meters, then when paying for utility services, the so-called. "pipe patency". In this case, the question of the tariffs applied in this case arises quite logically.

It is important to understand that the second option does not apply to private premises (apartments and cottages), where, in the absence of meters, sanitary standards are taken into account when calculating payment: usually this is up to 360 l/day per person.

What determines the permeability of a pipe?

What determines the flow of water in a pipe? round section? It seems that finding the answer should not be difficult: the larger the cross-section of the pipe, the greater the volume of water it can pass in a certain time. At the same time, pressure is also remembered, because the higher the water column, the faster the water will be forced inside the communication. However, practice shows that these are not all the factors influencing water consumption.

In addition to these, the following points must also be taken into account:

1. Pipe length. As its length increases, the water rubs against its walls more strongly, which leads to a slowdown in flow. Indeed, at the very beginning of the system, water is affected solely by pressure, but it is also important how quickly the next portions have the opportunity to enter the communication. The braking inside the pipe often reaches large values.
2. Water consumption depends on diameter to a much more complex extent than it seems at first glance. When the pipe diameter is small, the walls resist water flow an order of magnitude more than in thicker systems. As a result, as the pipe diameter decreases, its benefit in terms of the ratio of water flow velocity to internal area over a section of a fixed length decreases. To put it simply, a thick pipeline transports water much faster than a thin one.
3. Material of manufacture. Another important point, which directly affects the speed of water movement through the pipe. For example, smooth propylene promotes the sliding of water to a much greater extent than rough steel walls.
4. Duration of service. Over time, steel water pipes develop rust. In addition, it is typical for steel, like cast iron, to gradually accumulate lime deposits. The resistance to water flow of pipes with deposits is much higher than that of new steel products: this difference sometimes reaches up to 200 times. In addition, the overgrowth of the pipe leads to a decrease in its diameter: even if we do not take into account the increased friction, its permeability clearly decreases. It is also important to note that products made of plastic and metal-plastic do not have such problems: even after decades of intensive use, their level of resistance to water flows remains at the original level.
5. Availability of turns, fittings, adapters, valves contributes to additional inhibition of water flows.

All of the above factors must be taken into account, because we're talking about not about some small errors, but about a serious difference of several times. As a conclusion, we can say that a simple determination of the pipe diameter based on water flow is hardly possible.

New ability to calculate water consumption

If the water is used through a tap, this greatly simplifies the task. The main thing in this case is that the size of the water outflow hole is much smaller than the diameter of the water pipe. In this case, the formula for calculating water over the cross-section of a Torricelli pipe v^2=2gh is applicable, where v is the speed of flow through a small hole, g is the acceleration of free fall, and h is the height of the water column above the tap (a hole having a cross-section s, per unit time passes water volume s*v). It is important to remember that the term “section” is used not to denote the diameter, but its area. To calculate it, use the formula pi*r^2.

If the water column has a height of 10 meters and the hole has a diameter of 0.01 m, the water flow through the pipe at a pressure of one atmosphere is calculated as follows: v^2=2*9.78*10=195.6. After taking the square root, we get v=13.98570698963767. After rounding to get a simpler speed figure, the result is 14m/s. The cross-section of a hole having a diameter of 0.01 m is calculated as follows: 3.14159265*0.01^2=0.000314159265 m2. As a result, it turns out that the maximum water flow through the pipe corresponds to 0.000314159265*14 = 0.00439822971 m3/s (slightly less than 4.5 liters of water/second). As you can see, in this case, calculating water across the cross-section of a pipe is quite simple. There are also freely available special tables indicating water consumption for the most popular sanitary products, with a minimum value of the diameter of the water pipe.

As you can already understand, the universal simple way there is no way to calculate the diameter of the pipeline depending on the water flow. However, you can still derive certain indicators for yourself. This is especially true if the system is made of plastic or metal-plastic pipes, and water consumption is carried out by taps with a small outlet cross-section. In some cases, this calculation method is applicable to steel systems, but we are talking primarily about new water pipelines that have not yet become covered with internal deposits on the walls.

Water consumption by pipe diameter: determination of pipeline diameter depending on flow rate, calculation by cross-section, formula for maximum flow rate at pressure in a round pipe

Water consumption by pipe diameter: determination of pipeline diameter depending on flow rate, calculation by cross-section, formula for maximum flow rate at pressure in a round pipe

Water flow through a pipe: is a simple calculation possible?

Is it possible to make any simple calculation of water flow based on the diameter of the pipe? Or the only way is to contact specialists, having previously depicted detailed map all the water pipes in the area?

After all, hydrodynamic calculations are extremely complex...

Our task is to find out how much water this pipe can pass

What is it for?

1. When independently calculating water supply systems.

If you plan to build big house with several guest baths, a mini-hotel, think over a fire extinguishing system - it is advisable to know how much water a pipe of a given diameter can supply at a certain pressure.

After all, a significant drop in pressure during peak water consumption is unlikely to please residents. And a weak stream of water from a fire hose will most likely be useless.

1. In the absence of water meters, utilities usually bill organizations "by pipe flow."

Please note: the second scenario does not affect apartments and private houses. If there are no water meters, utilities charge for water according to sanitary standards. For modern well-maintained houses this is no more than 360 liters per person per day.

We must admit: a water meter greatly simplifies relations with utility services

Factors affecting pipe patency

What affects the maximum water flow in a round pipe?

The obvious answer

Common sense dictates that the answer should be very simple. There is a pipe for water supply. There is a hole in it. The larger it is, the more water will pass through it per unit of time. Oh, sorry, still pressure.

Obviously, a column of water 10 centimeters will push less water through a centimeter hole than a column of water the height of a ten-story building.

So, it depends on the internal cross-section of the pipe and on the pressure in the water supply system, right?

Is anything else really needed?

Correct answer

No. These factors affect consumption, but they are only the beginning of a long list. Calculating water flow based on the diameter of the pipe and the pressure in it is the same as calculating the trajectory of a rocket flying to the Moon based on the apparent position of our satellite.

If we do not take into account the rotation of the Earth, the movement of the Moon in its own orbit, the resistance of the atmosphere and the gravity of celestial bodies, it is unlikely that our spacecraft will reach even approximately the desired point in space.

How much water will flow out of a pipe with diameter x at line pressure y is influenced not only by these two factors, but also by:

• Pipe length. The longer it is, the more the friction of water against the walls slows down the flow of water in it. Yes, the water at the very end of the pipe is affected only by the pressure in it, but the following volumes of water must take its place. And the water pipe slows them down, and how.

It is precisely because of the loss of pressure in a long pipe that pumping stations are located on oil pipelines

• The diameter of the pipe affects water consumption in a much more complex way than it suggests. common sense» . For small-diameter pipes, the wall resistance to flow movement is much greater than for thick pipes.

The reason is that smaller pipe, the less favorable in terms of water flow rate is the ratio of internal volume and surface area at a fixed length.

Simply put, it is easier for water to move through a thick pipe than through a thin one.

• Wall material is another important factor on which the speed of water movement depends.. If water slides on smooth polypropylene, like the loin of a clumsy lady on a sidewalk in icy conditions, then rough steel creates much greater resistance to flow.
• The age of the pipe also greatly affects the permeability of the pipe.. Steel water pipes rust; in addition, steel and cast iron become overgrown with lime deposits over years of use.

An overgrown pipe has much greater resistance to flow (resistance to a polished new steel pipe and rusty differ 200 times!). Moreover, areas inside the pipe due to overgrowth reduce their clearance; even in ideal conditions Much less water will pass through an overgrown pipe.

Do you think it makes sense to calculate the permeability by the diameter of the pipe at the flange?

Please note: the surface condition of plastic and metal-polymer pipes does not deteriorate over time. After 20 years, the pipe will offer the same resistance to water flow as at the time of installation.

• Finally, any rotation, diameter transition, varied shut-off valves and fittings - all this also slows down the flow of water.

Ah, if only the above factors could be neglected! However, we are not talking about deviations within the error limits, but about a difference by several times.

All this leads us to a sad conclusion: a simple calculation of water flow through a pipe is impossible.

A ray of light in a dark kingdom

In the case of water flow through a tap, however, the task can be dramatically simplified. Basic condition simple calculation: The hole through which the water flows must be negligibly small compared to the diameter of the water supply pipe.

Then Torricelli's law applies: v^2=2gh, where v is the flow rate from a small hole, g is the acceleration of free fall, and h is the height of the water column that stands above the hole. In this case, a volume of liquid s*v will pass through a hole with a cross-section s per unit time.

The master left you a gift

Don't forget: the cross-section of a hole is not a diameter, it is an area equal to pi*r^2.

For a water column of 10 meters (which corresponds to excess pressure one atmosphere) and a hole with a diameter of 0.01 meters, the calculation will be as follows:

We extract Square root and we get v=13.98570698963767. For simplicity of calculations, we round the value of the flow speed to 14 m/s.

The cross-section of a hole with a diameter of 0.01 m is equal to 3.14159265*0.01^2=0.000314159265 m2.

Thus, the water flow through our hole will be equal to 0.000314159265*14=0.00439822971 m3/s, or slightly less than four and a half liters per second.

As you can see, in this version the calculation is not very complicated.

In addition, in the appendix to the article you will find a table of water consumption for the most common plumbing fixtures, indicating the minimum diameter of the connection.

Conclusion

That's all in a nutshell. As you can see, universal simple solution We have not found; however, we hope you find the article useful. Good luck!

How to calculate pipe capacity

Calculating throughput is one of the most complex tasks when laying a pipeline. In this article we will try to figure out exactly how this is done for different types pipelines and pipe materials.

High flow pipes

Bandwidth – important parameter for any pipes, canals and other heirs of the Roman aqueduct. However, the throughput capacity is not always indicated on the pipe packaging (or on the product itself). In addition, the layout of the pipeline also determines how much liquid the pipe passes through the cross-section. How to correctly calculate the throughput of pipelines?

Methods for calculating pipeline capacity

There are several methods for calculating this parameter, each of which is suitable for a particular case. Some symbols important when determining pipe capacity:

Outer diameter is the physical size of the pipe cross-section from one edge of the outer wall to the other. In calculations it is designated as Dn or Dn. This parameter is indicated in the labeling.

Nominal diameter is the approximate value of the diameter of the internal section of the pipe, rounded to the nearest whole number. In calculations it is designated as Du or Du.

Physical methods for calculating pipe capacity

Pipe throughput values ​​are determined using special formulas. For each type of product - for gas, water supply, sewerage - there are different calculation methods.

Tabular calculation methods

There is a table of approximate values ​​created to make it easier to determine the capacity of pipes in apartment wiring. In most cases high accuracy is not required, so the values ​​can be applied without complex calculations. But this table does not take into account the decrease in throughput due to the appearance of sedimentary growths inside the pipe, which is typical for old highways.

There is an exact table for calculating capacity, called the Shevelev table, which takes into account the pipe material and many other factors. These tables are rarely used when laying water pipes in an apartment, but in a private house with several non-standard risers they can be useful.

Calculation using programs

Modern plumbing companies have special computer programs at their disposal to calculate pipe capacity, as well as many other similar parameters. In addition, online calculators have been developed, which, although less accurate, are free and do not require installation on a PC. One of the stationary programs “TAScope” is a creation of Western engineers, which is shareware. Large companies use "Hydrosystem" - this is a domestic program that calculates pipes according to criteria that affect their operation in the regions of the Russian Federation. In addition to hydraulic calculations, it allows you to calculate other pipeline parameters. average price 150,000 rubles.

How to calculate the capacity of a gas pipe

Gas is one of the most difficult materials to transport, in particular because it tends to be compressed and therefore is able to leak through the smallest gaps in pipes. To calculate throughput gas pipes(as well as for design gas system in general) have special requirements.

Formula for calculating the capacity of a gas pipe

The maximum throughput of gas pipelines is determined by the formula:

Qmax = 0.67 DN2 * p

where p is equal to the operating pressure in the gas pipeline system + 0.10 MPa or absolute gas pressure;

Du – conditional diameter of the pipe.

There is a complex formula for calculating the capacity of a gas pipe. It is usually not used when carrying out preliminary calculations, as well as when calculating a household gas pipeline.

Qmax = 196.386 DN2 * p/z*T

where z is the compressibility coefficient;

T is the temperature of the transported gas, K;

According to this formula, the direct dependence of the temperature of the moving medium on pressure is determined. The higher the T value, the more the gas expands and presses on the walls. Therefore, when calculating large highways, engineers take into account possible weather conditions in the area where the pipeline runs. If the nominal value of the pipe DN is less than the gas pressure generated by high temperatures in summer (for example, at +38...+45 degrees Celsius), then damage to the main line is likely. This entails the leakage of valuable raw materials and creates the possibility of an explosion in a section of the pipe.

Table of gas pipe capacities depending on pressure

There is a table for calculating gas pipeline throughputs for commonly used pipe diameters and nominal operating pressures. To determine the characteristics of the gas main non-standard sizes and pressure will be required engineering calculations. The pressure, speed and volume of gas are also affected by the outside air temperature.

The maximum speed (W) of the gas in the table is 25 m/s, and z (compressibility coefficient) is 1. The temperature (T) is 20 degrees Celsius or 293 Kelvin.

Sewer pipe capacity

Bandwidth sewer pipe– an important parameter that depends on the type of pipeline (pressure or non-pressure). The calculation formula is based on the laws of hydraulics. In addition to labor-intensive calculations, tables are used to determine sewer capacity.

Hydraulic calculation formula

For hydraulic calculation of sewerage, it is necessary to determine the unknowns:

1. pipeline diameter Du;
2. average flow velocity v;
3. hydraulic slope l;
4. degree of filling h/Dn (calculations are based on the hydraulic radius, which is associated with this value).

In practice, they are limited to calculating the value of l or h/d, since the remaining parameters are easy to calculate. Hydraulic slope in preliminary calculations is considered to be equal to the slope of the earth's surface at which the movement Wastewater will not be lower than the self-cleaning speed. Speed ​​values, as well as maximum h/DN values ​​for household networks can be found in Table 3.

In addition, there is a normalized value minimum slope for pipes with small diameter: 150 mm

(i=0.008) and 200 (i=0.007) mm.

The formula for volumetric fluid flow looks like this:

where a is the open cross-sectional area of ​​the flow,

v – flow velocity, m/s.

Speed ​​is calculated using the formula:

where R is the hydraulic radius;

C – wetting coefficient;

From this we can derive the formula for hydraulic slope:

This parameter is used to determine this parameter if calculation is necessary.

where n is the roughness coefficient, having values ​​from 0.012 to 0.015 depending on the pipe material.

The hydraulic radius is considered equal to the normal radius, but only when the pipe is completely filled. In other cases, use the formula:

where A is the area of ​​the transverse fluid flow,

P is the wetted perimeter, or the transverse length of the inner surface of the pipe that touches the liquid.

Bandwidth tables without pressure pipes sewer

The table takes into account all the parameters used to perform the hydraulic calculation. The data is selected according to the pipe diameter and substituted into the formula. Here the volumetric flow rate of liquid q passing through the cross-section of the pipe has already been calculated, which can be taken as the throughput of the line.

In addition, there are more detailed Lukin tables containing ready-made throughput values ​​for pipes of different diameters from 50 to 2000 mm.

Capacity tables for pressure sewer systems

In the capacity tables for sewerage pressure pipes, the values ​​depend on the maximum degree of filling and the design average speed waste water.

Water pipe capacity

Water pipes are the most commonly used pipes in a home. And since they are subject to a large load, calculating the throughput of the water main becomes an important condition for reliable operation.

Pipe patency depending on diameter

Diameter is not the most important parameter when calculating the patency of a pipe, but it also affects its value. The larger the internal diameter of the pipe, the higher the permeability, and also the lower the chance of blockages and plugs. However, in addition to the diameter, it is necessary to take into account the coefficient of friction of water on the pipe walls (tabular value for each material), the length of the line and the difference in fluid pressure at the inlet and outlet. In addition, the number of elbows and fittings in the pipeline will greatly influence the flow rate.

Table of pipe capacity by coolant temperature

The higher the temperature in the pipe, the lower its throughput, since the water expands and thereby creates additional friction. For plumbing this is not important, but in heating systems is a key parameter.

There is a table for calculations of heat and coolant.

Table of pipe capacity depending on coolant pressure

There is a table describing the capacity of pipes depending on pressure.

Table of pipe capacity depending on diameter (according to Shevelev)

The tables of F.A. and A.F. Shevelev are one of the most accurate tabular methods for calculating the throughput of a water pipeline. In addition, they contain all the necessary calculation formulas for each specific material. This is a lengthy piece of information that is most often used by hydraulic engineers.

The tables take into account:

1. pipe diameters – internal and external;
2. wall thickness;
3. service life of the water supply system;
4. line length;
5. purpose of pipes.

Pipe throughput depending on diameter, pressure: tables, calculation formulas, online calculator

Calculating capacity is one of the most difficult tasks when laying a pipeline. In this article we will try to figure out exactly how this is done for different types of pipelines and pipe materials.

When laying water mains, the most difficult thing is to calculate the throughput of pipe sections. Correct calculations will ensure that the water consumption is not too high and its pressure does not decrease.

The importance of correct calculations

Calculating water consumption allows you to choose the right pipe material and diameter

When designing a cottage with two or more bathrooms or a small hotel, one must take into account how much water the pipes of the selected section can supply. After all, if the pressure in the pipeline drops due to high consumption, this will lead to the fact that it will be impossible to take a normal shower or bath. If the problem arises in a fire, you could lose your home altogether. Therefore, the calculation of the trafficability of highways is carried out even before the start of construction.

It is also important for small business owners to know throughput rates. Indeed, in the absence of metering devices, utility services, as a rule, present an invoice for water consumption to organizations based on the volume passed through the pipe. Knowing the data on your water supply will allow you to control water consumption and not pay extra.

What determines the permeability of a pipe?

Water consumption will depend on the configuration of the water supply system, as well as the type of pipes from which the network is installed

The permeability of pipe sections is a metric value that characterizes the volume of liquid passed through the pipeline over a certain time interval. This indicator depends on the material used in the production of pipes.

Plastic pipelines maintain almost the same permeability throughout the entire operational period. Plastic, compared to metal, does not rust, so the lines do not become clogged for a long time.

For metal models, throughput decreases year after year. Due to the fact that pipes rust, inner surface gradually peels off and becomes rough. Because of this, much more plaque forms on the walls. Hot water pipes in particular clog quickly.

In addition to the material of manufacture, cross-country ability also depends on other characteristics:

• Pipeline lengths. The greater the length, the lower the flow velocity due to the influence of friction, and the pressure decreases accordingly.
• Pipe diameter. The walls of narrow highways create more resistance. The smaller the cross-section, the worse the ratio of flow velocity to internal area will be over a section of a fixed length. Wider pipes move water faster.
• Presence of turns, fittings, adapters, taps. Any shaped parts slow down the movement of water flows.

When determining the throughput indicator, it is necessary to take into account all these factors in combination. In order not to get confused in the numbers, you should use proven formulas and tables.

Calculation methods

The friction coefficient is affected by the presence locking elements and their number

To determine the permeability of a water supply system, you can use three calculation methods:

The last method, although the most accurate, is not suitable for calculating ordinary household communications. It is quite complex, and to use it you will need to know a variety of indicators. To calculate simple network for a private home, you should use an online calculator. Although it is not as accurate, it is free and does not need to be installed on your computer. You can achieve more accurate information by checking the data calculated by the program with the table.

How to Calculate Bandwidth

The tabular method is the simplest. Several calculation tables have been developed: you can choose the one that is suitable depending on the known parameters.

Calculation based on pipe section

SNiP 2.04.01-85 proposes to find out the amount of water consumption by the girth of the pipe.

In accordance with SNiP standards, daily water consumption by one person is no more than 60 liters. This data is for a home without running water. If a water supply network is installed, the volume increases to 200 liters.

Calculation based on coolant temperature

As the temperature rises, the permeability of the pipe decreases - the water expands and thereby creates additional friction.

You can calculate the necessary data using a special table:

Pipe section (mm)	Bandwidth
	By heat (hl/h)		By coolant (t/h)
	Water	Steam	Water	Steam
15	0,011	0,005	0,182	0,009
25	0,039	0,018	0,650	0,033
38	0,11	0,05	1,82	0,091
50	0,24	0,11	4,00	0,20
75	0,72	0,33	12,0	0,60
100	1,51	0,69	25,0	1,25
125	2,70	1,24	45,0	2,25
150	4,36	2,00	72,8	3,64
200	9,23	4,24	154	7,70
250	16,6	7,60	276	13,8
300	26,6	12,2	444	22,2
350	40,3	18,5	672	33,6
400	56,5	26,0	940	47,0
450	68,3	36,0	1310	65,5
500	103	47,4	1730	86,5
600	167	76,5	2780	139
700	250	115	4160	208
800	354	162	5900	295
900	633	291	10500	525
1000	1020	470	17100	855

For summing up plumbing system this information is not extremely important, but is considered the main indicator for heating circuits.

Find data based on pressure

The water flow pressure of the common main is taken into account when selecting pipes

When selecting pipes for installing any communication network, you need to take into account the flow pressure in the common line. If pressure is provided high pressure, it is necessary to install pipes with a larger cross-section than when moving by gravity. If these parameters are not taken into account when selecting pipe sections, and a large water flow is passed through small networks, they will begin to make noise, vibrate and quickly become unusable.

To find the highest calculated water flow, use a table of pipe capacity depending on the diameter and various water pressure indicators:

Consumption		Bandwidth
Pipe section		15 mm	20 mm	25 mm	32 mm	40 mm	50 mm	65 mm	80 mm	100 mm
Pa/m	Mbar/m	Less than 0.15 m/s			0.15 m/s					0.3 m/s
90,0	0,900	173	403	745	1627	2488	4716	9612	14940	30240
92,5	0,925	176	407	756	1652	2524	4788	9756	15156	30672
95,0	0,950	176	414	767	1678	2560	4860	9900	15372	31104
97,5	0,975	180	421	778	1699	2596	4932	10044	15552	31500
100,0	1000,0	184	425	788	1724	2632	5004	10152	15768	31932
120,0	1200,0	202	472	871	1897	2898	5508	11196	17352	35100
140,0	1400,0	220	511	943	2059	3143	5976	12132	18792	38160
160,0	1600,0	234	547	1015	2210	3373	6408	12996	20160	40680
180,0	1800,0	252	583	1080	2354	3589	6804	13824	21420	43200
200,0	2000,0	266	619	1151	2488	3780	7200	14580	22644	45720
220,0	2200,0	281	652	1202	2617	3996	7560	15336	23760	47880
240,0	2400,0	288	680	1256	2740	4176	7920	16056	24876	50400
260,0	2600,0	306	713	1310	2855	4356	8244	16740	25920	52200
280,0	2800,0	317	742	1364	2970	4356	8568	17338	26928	54360
300,0	3000,	331	767	1415	3078	4680	8892	18000	27900	56160

The average pressure in most risers varies from 1.5 to 2.5 atmospheres. The dependence on the number of floors is regulated by dividing the water supply network into several branches. Injecting water through pumps also affects the change in flow speed.

Also, when calculating the water flow through a pipe using a table of pipe diameter and pressure values, not only the number of taps is taken into account, but also the number of water heaters, bathtubs and other consumers.

Hydraulic calculation according to Shevelev

To most accurately identify the indicators of the entire water supply network, special reference materials are used. They define the running characteristics for pipes made of different materials.