Pressure in the pipes of water supply: understand the

The pressure in the water pipe is one of the most important parameters determining the operation of the entire system. Although most of us have a very superficial idea about the principles of its adjustment, it’s still worth reading the nuances. At a minimum, this way we will be able to effectively design a water supply system and select the appropriate equipment for it.

Rationing indicators

For the apartment as a whole

Very often, especially in the morning and evening hours, the residents of the upper floors of apartment buildings instead of the flow of water from the tap observe a rather thin stream. Typically, this situation is caused by a one-time selection of a large amount of water - literally not enough for everyone.

But if the lack of fluid is observed at another time, then this most likely indicates an insufficient head: the pressure in the pipes is too low, and the water simply does not rise to a certain height. (See also the article Pipe Capacity: Features.)

However, both “high” and “low” pressure are conventions.

What is the norm in this case?

Note! The “official” unit for measuring the pressure of water in pipes is 1 bar, but in practice they usually use signs in atmospheres. In principle, these values ​​are equivalent, since 1 Bar = 1, 019 atmospheres, which corresponds to approximately 10 m of the water column. Also in some cases, the designation is used in megapascals (MPa)

• According to construction standards, the optimal pressure in the pipes of the water supply system is up to 4 atmospheres (0.4 MPa).
• At the same time, the actual value of this indicator at a particular point is largely determined by its location, and for household appliances it ranges from 2 to 5.5 atmospheres.
• As an upper limit of pressure, SNIP 2.04.01- 85 indicates a value of 6 bar. With such loads, there is a probability of failure of sensitive plumbing, and the risk of leakage also increases.

• At the same time, it should be noted that, according to the already mentioned standard, the water supply system itself must withstand at least 10 atmospheres - it is with this pressure indicator that the pipe system is pressure tested annually.

The calculation of pressure in the system in this case is carried out according to the following formula:

Р = 10 + height of one floor (m) * (h - 1), where h is the number of floors of the tallest building in the microdistrict that the system serves.

Naturally, only professionals with access to stop valves of central highways can use this formula in practice, but everyone needs to understand the mechanism of calculations. Then, at a minimum, we will be able to reasonably demand compliance with the standards for pressure in our cranes.

Note! The flow of water through the pipe at a pressure of a certain value can also be established by calculation. However, for this, quite complex formulas are used, because experts recommend either using calculator programs, or simply taking measurements using suitable containers.

For various household appliances

The pressure itself is not critical: if necessary, just wait, and the bathroom will fill even with the thinnest jet. But modern household appliances are usually developed with the expectation of a certain water pressure, and at smaller values ​​simply will not be able to work effectively.

The values ​​of the optimal pressure for different devices are given in the table:

If you are planning to buy household appliances, it is advisable to determine in advance whether it will be able to function effectively when connected to your water supply system. Usually, the device manual contains all the necessary information, but in some cases expert advice may be needed.

For a private house

If you decide to design the water supply system of a private house with your own hands, then in the matter of adjusting the pressure in the system you will encounter such nuances:

• First of all, we will have to organize the rise of water from the source (well or well) to the water intake points. Pumps are commonly used for this, but their capacity is limited by the well’s flow rate.
• If there is a free-flow source on the site, then our task is to increase the pressure. And since the daily need for water may exceed the flow rate, to reduce the risk of drying, it is recommended to install high-capacity accumulators that will act as a reservoir.

Tip! To determine how much water your family consumes per day, preferably in the summer during the peak irrigation season.

• With pressure (artesian) wells, the problem is somewhat different.. As a rule, they are characterized by a large flow rate, and therefore are able to raise the pressure in the system to 6 atmospheres and above. Exceeding the optimal level can lead to deterioration of plumbing and leaks, because here we will have to equalize the pressure, ensuring its reduction.

Ways to increase pressure

If there is a need to increase the head, then such measures should be taken:

• First, at the entrance to the apartment, you can install a small pump that operates on the network. Of course, he will not be able to fundamentally correct the situation, but usually it provides a minimum level of 1.5 bar.
• In a private house, an automatic pumping station that regulates water intake from a source becomes a solution. The installation of a large-capacity pumping tank can increase its efficiency: a reserve corresponding to the daily water demand is sometimes very useful.

Note! Pumping stations with a tank can be installed in apartments, but they take up quite a lot of space. Yes, and the price of the device is large enough, so before buying it is worth to weigh all the risks.

• Another requirement for increasing the pressure in the system is proper arrangement of the wellhead. In case of violation of its tightness, problems with the operation of water-lifting equipment begin, and the pressure decreases.

Conclusion

Information on how to calculate the pressure of water in a pipe for a given situation may be useful both for owners of private houses and apartment residents. And even if you do not plan to do the laying of pipelines on your own, it’s still worth exploring the nuances to control the work of the masters.

The video in this article will help you to understand a number of difficult moments, so if possible carefully review it.