What pressure is the norm in the water supply network?

Working pressure in the water supply system performs a difficult task. The efficiency of many household appliances depends on the efficiency of the pressure. In the shower, a high indicator is most important, otherwise the water will just ooze out of the watering can, not being able to climb the riser.

City and private pipeline pressure

According to GOST, the pressure in the water supply network should be 4 bar

Pressure optimization in the city water supply system is impossible, in addition, accurate information about the pressure force is not currently provided. If the line meets the established GOST, the pressure will be 4 bar. However, this indicator often drops to 2.5-2.7 bar. Therefore, water consumption can be minimal.

In a private (autonomous) water supply, the water pressure is calculated individually. It depends on the type of plumbing chosen, as well as the resistance indicator when passing a resource through pipes from a source. A huge role is played by the selected pumping equipment. The optimal indicator in the private sector is a pressure of 1.5-2 bar. This can be checked with a manometer.

Regulatory requirements

Measurements of water pressure in apartment buildings and in the private sector have practically no differences. Each type of pipeline has its own limit. For example, a normal indicator corresponds to 1 bar, i.e. 1.0197 Atmospheres.

In communication water mains, an excess of 4 bar is not permissible. They are able to supply water to a height of risers up to 10 meters. With such data, the water pressure will be the same on all floors. However, such high pressure is rare. A typical water supply construction has a mark of 2.5-7.5 bar, the latter being considered high for ordinary water supply for private and multi-apartment buildings.

If the mark in the city pipeline exceeds 6.5 bar, this can damage a number of electrical appliances: washing machine, boiler, dishwasher. Values ​​up to 10 bar are used only in industrial pipelines having suture and threaded joints.

If a jacuzzi is installed in the house, the pressure indicator for hot water supply of 4 bar is enough for him. The washing machine and shower will operate at a stable pressure of 1.5 bar. Thus, the same standard for urban and private water supply is a pressure indicator of 4 bar. During the initial water supply, it is necessary to find out what exactly the indicators will be.

Pressure unit

When the owner of a house or apartment notices that household appliances are not doing their job, the suspicion falls on poor-quality water supply. It is necessary to carry out measurements, for which it is necessary to know exactly the unit by which the pressure force in water systems is determined. Different units of water pressure in the water supply can be used.

  • The value of the water column, which is determined for hydraulic calculations. It corresponds to hydrostatic pressure with a column size of 1 mm and a simultaneous temperature of 4 degrees.
  • Bar. Its value is equated to one atmosphere or is replaced by a rise of 10 meters of water. In this case, uninterrupted operation of the dishwasher will be carried out only at a pressure indicator of at least 2 bar. This can be calculated using a special formula. Raise or lower it is permissible in extreme cases.
  • The technical atmosphere. It is determined using the value of the oceans.For example, 1 atmosphere is fully consistent with the pressure at the time of applying a force equal to 1 kg per area of ​​1 cm2.
  • Pascal. Its value implies 1 Newton, multiplied by 1 sq.m. Such a unit belongs to international systems, therefore it is used less often in our country.
  • PSI psi square. One PSI unit corresponds to a constant value of 6894.75729 Pa, can be calculated in MPa. Most often used on automobile pressure gauges, but sometimes on devices for determining water pressure.

SNiP indicates that the maximum pressure should be no more than 6 atmospheres, while the lower limit should correspond to 0.2 atmospheres or more. The standard table provided by each supplier will help to verify this.

If the pressure meets regulatory requirements, water can be provided to all residents of apartment buildings without exception.

Water pressure calculation

Pressure depending on pipe diameter

If there is an installed pressure gauge on the pipe entering the house or apartment, the pressure will be measured automatically without manual calculations. Otherwise, you have to calculate this value. This procedure takes no more than five minutes. How much will be the indicator, you can understand without calculations. Prepare a toolbox:

  • removable pressure gauge;
  • a hose having a similar diameter as on a pipe;
  • ½ ”threaded fitting;
  • plumbing tape and clamp.

A pressure gauge is fixed on one side of the hose with a clamp, a fitting is inserted into the opposite hole and fixed in the same way. The shower head is removed, a fitting is inserted in its place and the water is switched several times: shower faucet. This will help drive out the accumulated air. If smudges appear at the joints, it is necessary to eliminate them by wrapping plumbing tape. After that, on the manometer, the arrow will show the pressure level in the pipeline.

Ways to increase and decrease the pressure of the pipeline

Pump to increase water pressure

Inconsistency with the pressure standards in the pipeline often leads to trouble, so you have to fix this problem with your own hands if the water utility does not provide such a service. There are several methods that help to increase and, if necessary, reduce the water pressure in the line.

Options for increasing pressure in an autonomous and apartment pipeline

There are two ways to increase pressure and use water for your own pleasure without pressure drops. For such purposes, residents can create special conditions: install apartment pumps or pumping stations.

  1. Ordinary pump. Installation is carried out on a water supply pipe in houses or apartments at the point where the resource is taken - not far from the faucet or shower head. This device can be used if you need to increase the indicator pressure to 1.5 bar. The equipment is easily maintained and does not require additional components. To improve performance, it is necessary to select a more serious device.
  2. Pumping station. More suitable for owners of private homes with autonomous water supply. For the operation of such a design, it is necessary to have additional space, since the pump station is installed in conjunction with a storage tank. For such purposes, a basement is suitable. Due to the presence of an expansion tank, even when the centralized cold water supply is turned off, the pressure will be maintained and the owner will have enough resource for a day.

Any pump in the system has built-in sensors and control mechanisms that start / stop the device in case of lowering the optimal pressure indicator or increasing it. Thus, it turns out to reduce or increase indicators.

Methods of reducing the pressure in the water supply

To lower the water pressure in the water supply network, it will be necessary to install a reducer in the main at the place where the pipe enters the house or apartment. Such a mechanism is a small design with two threaded connections. They perfectly protect household appliances from water hammer and reduce the load on the home pipeline as a whole.

The principle of operation of the regulator is to equalize the force of the diaphragm and the holding spring. As soon as the intake takes place, the pressure drops, so the action of the spring is amplified. In this case, the hole opens until the pressure in the pipeline stabilizes. Accordingly, if pressure builds up, this will not affect the opening and closing of the built-in valve, so the user will receive a resource with a stable pressure.

Causes of weak pressure in the pipes

A number of cases have been recorded due to which the pressure of water in any type of pipeline can decrease.

  • The presence of large blockage in the cross section of the pipeline, sediment and other sediments. Over time, the lumen of the nozzles decreases, respectively, and the pressure can drop.
  • Accident at the pumping station. If the equipment is not working properly, there may be some problems with the rate of water supply to houses. This may be accompanied by a decrease in pressure or its complete absence for a long time.
  • There is no electricity. The pumping station works from the mains, so when it is turned off, there is a decrease in water supply to multi-apartment and private houses.
  • Leakage. If there is a loss of life in the line suitable for the house, this significantly affects the pressure. In such circumstances, the pressure decreases, and water can flow in a thin stream.
  • Increased water intake. This problem is observed in late spring, summer and autumn. Most of the population is gardening, making preparations for the winter. In many, fruits grow directly on the house plot, even in multi-storey residential areas.

Residents can only endure interruptions in the supply of water. In the best case, you can write a collective letter to an organization that provides water supply services. A prerequisite for this is the requirement to regularly measure the water pressure in the pipeline.

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