Standards for water pressure in the water supply in an apartment, methods for measuring and normalizing it

Modern life cannot be imagined without running water in an apartment.Water supply is a complex and multifunctional process, the operation of which for normal human life must be provided around the clock and with the required pressure. Although the latter can often cause problems.

In this material we will look at what standards exist for water pressure in the water supply in an apartment and what can be done if the prescribed standards are not met. This information will be useful to consumers of water supply services in an apartment building.

We will supplement the presented material with visual photographs and video tips on installing equipment that allows you to increase the pressure in the water supply.

Water pressure standards

In regulatory documents regulating standards relating to water supply systems, parameters such as water pressure and minimum free pressure are found.

Pressure measurement values

In order to correctly understand the standards specified in the documents, which prescribe at what pressure water should be supplied to the water supply system of an apartment building, it is necessary to understand the relationship between these quantities.

In short, then water pressure characterizes the force acting on an obstacle in the path of the flow. Thus, pressure has potential energy.

In a moving fluid there is no pressure, but the pressure, comparable to kinetic energy and representing a linear unit, is maximum.

Found in regulatory documents free head indicator means the smallest height to which water needs to be raised, taking into account losses to overcome the resistance of the pipes, above ground level in order to reach the water collection point.

Both of these quantities can transform into each other.

For example, a pumping station of an apartment building that raises water to a height of forty meters creates a water column pressure at the outlet equal to 4 atm or 4 bar

Water pressure can be measured in different units. Since 1 bar ≈ 0.99 physical atmosphere (atm), these values ​​are conventionally equated. 1 atm or 1 kg/cm technical atmosphere (at) corresponds to the pressure created by a 10 meter water column.

In the metric system of measures, the Pascal is the base unit for measuring pressure. For water, the measurement is carried out in megapascals (MPa). Non-systemic units include: bars, atmospheres, kgf/cm².

Standard indicators of pressure in pipelines

The main regulatory documents defining the water pressure values ​​guaranteed by the water supply organization in the utilities of an apartment building are:

1. Set of rules SP 30.13330.2016.
2. Decree of the Government of the Russian Federation dated May 6, 2011 No. 354.

The first document established the standard water pressure at the level of the lowest sanitary equipment located in the house.

Resolution No. 354 regulates the quality requirements for supplied utilities, including defining pressure standards in residential buildings for cold water supply and hot water supply at the points of collection.

However, to find answers to questions about what the pressure and pressure of water should be in the water supply system in an apartment, being guided only by these documents, especially when making calculations for installing a pressure-increasing pump in an apartment, will not be enough.

To do this you need to use the following methods:

• SNiP 2.04.02-84 — determines the norms of water pressure at the entrance to the house;
• SNiP 2.04.01-85 — normalizes the pressure at the water supply in the apartment.

By coordinating all these documents with each other, it is possible to derive the main standard values ​​​​for water pressure.

At the entrance to a one-story building, the minimum water pressure must be no less than 10 m. In an apartment building, 4 m is added to each floor

For example, for a house with 8 floors, the input water pressure should be at least: 10 m + (4 m × 7 floors) = 38 m or 3.8 atm (kg/cm2).

The pressure at the water intake point at the entrance to the apartment of the house must be ensured:

• HVS ranging from 0.03 MPa (0.3 atm) to 0.6 MPa (6.0 atm);
• DHW - from 0.03 MPa (0.3 atm.) to 0.45 MPa (4.5 atm).

No less than the value of free water pressure in an apartment for specific plumbing fixtures that have mixers is also regulated by SNiP:

• washbasin—0.2 at;
• bath - 0.3 at;
• shower cabin—0.3 at.

Taking into account the above indicators, when choosing a plumbing fixture, you need to pay attention to the minimum pressure value at which it is designed to operate.

Some old geysers can only operate with a minimum water pressure of 0.9 atm, while the lower limit of the standard is 0.3 atm

Therefore, devices whose characteristics indicate parameters below the standard can be considered as not intended for installation on specific utility networks and subject to replacement.

This nuance should also be taken into account - the given building standards determine the permissible minimum or maximum limits for water pressure, and this permitted range is quite large.

In practice, the optimal value of water pressure in the intra-apartment network, which ensures its comfortable use and correct operation of household appliances, is 4 atm.

If you live in a private house or use a summer house with an autonomous water supply, we recommend that you familiarize yourself with the pressure standards in the system private water supply and ways to improve it.

Methods of taking readings

Theoretical knowledge of standard values ​​​​relating to water pressure allows us to move on to practice, which gives an answer to the question of how to measure water pressure at home in a tap or other water points in an apartment.

Method #1 - using stationary pressure gauges

The main device for measuring pressure in water supply lines is a pressure gauge. There are several types of devices for this purpose, differing in design and operating principle.

The most common type of water pressure reading device is a mechanical pressure gauge. It is reliable in operation, has an easy to read scale of values ​​and an information dial

Often, monitoring the water pressure in an apartment is limited to the readings of a device installed at the boundary separating the intra-apartment and central pipelines. However, in reality, the readings of such a pressure gauge will not be entirely correct and will be accepted with some errors.

This is due to the fact that all pressure losses on the elements of the apartment’s internal wiring (filters, tees, shut-off and control valves) are not taken into account. In addition, the free water pressure is affected by turns and sections with changes in pipeline cross-sections.

Therefore, the best option is to equip all entrances to water consumption points in the apartment with pressure gauges. This is quite accessible at the stages of housing construction or during repair work to replace water supply pipelines.

The absence of permanently installed devices does not deprive the consumer of the opportunity to measure water pressure at any water point by other means.

Method #2 - using a portable pressure gauge

A special feature of the portable measuring device is its versatility and the possibility of simple installation on pipelines and equally simple dismantling.

The use of this method allows you to measure water pressure directly at the inlet of each plumbing fixture that affects its pressure.

You can assemble a mobile pressure gauge with your own hands by improving a purchased factory device. To do this you need: 1 - a regular water pressure gauge with a scale of up to 6 bar; 2 - threaded extension; 3—adapter from 3/8-inch pressure gauge thread to half-inch extension thread

Fum tape is used to seal threaded connections.

The most convenient connection point for measuring water pressure is the shower.

The measurement algorithm is as follows:

1. The shower head is unscrewed from the hose.
2. A pressure gauge is mounted on the hose.
3. The shower tap opens.
4. The pressure is measured.

To take correct readings from the device, it is necessary to get rid of the air plug during the measurement process. It can be eliminated by several switches of the mixer from the tap to the shower or by opening and closing another tap in the water supply system.

If there is no appropriate adapter, then instead you can select a hose with a diameter that allows you to connect it to a pressure gauge. The connection to the shower hose in this case is made through a fitting with a ½-inch thread.

The water pressure may fluctuate during the day, therefore, to ensure the reliability of the readings taken, it is recommended to take measurements several times, including during the period of peak water collection.

Method #3 - non-instrumental pressure determination

This method allows you to measure water pressure at the point of connection to plumbing fixtures with a certain degree of error without the use of special measuring devices.

To take measurements, you need to purchase a transparent PVC hose/tube about two meters long and with a diameter that allows you to connect it to a water tap

An experiment using a transparent PVC hose is carried out according to the following method:

1. One end of the hose is connected to the disassembly point, positioned and, preferably, fixed in a vertical position.
2. The tap opens and the tube is filled with water to the mark corresponding to the bottom of the tap (zero level).
3. The top hole is hermetically sealed.
4. The water tap is opened to maximum pressure.
5. The height of the water column is measured from the zero level to the lower boundary of the air plug (H).
6. The height of the air plug (h) is fixed.

Distance measurements should not be carried out immediately, but after 1-2 minutes, after an air plug forms in the hose under water pressure from an open tap.

The formula for calculating the approximate value of water pressure from an open tap, when using a transparent hose as a pressure gauge, will be as follows. P=Ratm × (N + h) / h

The value of Ratm is taken to be the value of the atmospheric pressure in the tube before the start of the experiment - 1 atm.

Causes of low pressure and prevention

The responsibility for ensuring the required pressure in the water supply system of an apartment building rests with the organization that maintains the house. As a rule, this is a management company, but also, an agreement for a water supply service can be concluded directly with the supplier of this service.

Therefore, the first thing that needs to be done when there is a general decrease in water pressure in the house or in the riser is to inform the responsible organization in accordance with the established procedure, preferably in writing, to take response measures.

But, unfortunately, very often residents have to deal with water pressure in apartments that does not meet the required standards on their own.

In most cases, the main problem is low water pressure.

In order to make the right technical decision to correct the situation, without damage to the water system and consumers, it is necessary, first of all, to establish the reasons causing its decline.

Such factors may include:

• malfunctions, in the form of leaks and ruptures on utility networks, shut-off valves, fittings;
• slagging pipelines, resulting in a reduction in their throughput.

Elimination of faults on public building networks by the management company and implementation of a set of measures for their timely maintenance can sometimes completely solve this problem.

A local decrease in water pressure in the apartment indicates a malfunction of the plumbing, and one of the reasons may be clogged water purification filters

In addition to coarse filters, as a rule, fine filters are installed for all household appliances that consume water in the apartment. And the prevention of failures in the operation of these devices due to a decrease in pressure is to clean all filter elements.

Consequences of pressure deviations from the norm

One of the important technical characteristics that determine the normal functioning of the water supply system is water pressure. Non-compliance with its established values ​​in either direction can cause a number of problems.

High blood pressure poses a threat:

• violation of the integrity of threaded connections, couplings, fittings;
• damage to ceramic valves;
• failure of valves and other equipment of household appliances connected to the water supply.

Insufficient water pressure can cause not only everyday inconveniences that arise, for example, when washing dishes, taking a shower, but also a complete failure of operation - in the worst case, some sanitary appliances, geysers and instantaneous water heaters.

The compliance of water pressure in the pipelines of an apartment building with established regulatory values ​​and standards must be monitored by the management company or the provider of this service. If necessary, adjustment work is carried out on the system

Any deviation of water pressure from the normatively prescribed one requires determining the cause of this malfunction and urgently taking measures to normalize the pressure.

Ways to increase pressure in the system

The problem with water pressure, especially in old houses, may be of a structural and technical nature, over which utility workers are powerless. Also, to save energy resources, suppliers often turn off one or more general house booster pumps. Due to redundant circuits, the water supply does not stop completely, but the pressure in the system is significantly reduced.

In such a situation, it becomes necessary to use one of two or two simultaneous methods of equipping the water supply network with additional equipment to increase the pressure and pressure of water.

Method #1 - flow pump

Pumps of this type increase water pressure without additional intake, and no permits are required for their installation in apartments.

There are several types of these devices, differing in characteristics such as:

• type of control (manual, automatic);
• permitted water temperature;
• cooling method.

The built-in sensor of the device automatically reacts to a drop in pressure in the system and raises it to the optimal value.

Structurally, a flow pump consists of a wet rotor, which is located in the pumped water. The rotor is separated from the starter by a thin stainless steel sleeve

Units of this type are classified as surface circulation pumps. They are easily and quickly installed on existing utility networks. As a rule, additional reconstruction of the system to install flow pumps is not required.

The pressure pumped by the pump can be adjusted either manually or automatically.

At pump selection it is necessary to compare its performance with water consumption in the apartment, so that when several household appliances that consume water are used simultaneously, the unit’s throughput is sufficient for their normal operation.

For example, a pump with a capacity of 3.5 m will be sufficient for three water collection points.³ /hour.

Flow-through circulation pumps, small in size and weight, can be installed at the entrance of the central main line to the apartment, as well as directly in front of the water-consuming plumbing household appliance or geyser.

Among the most popular models of units for this purpose, we can highlight the device from the Belgian manufacturer Grundfos UPA 15-90, which has great market demand and a decent price-quality ratio.

The pump has a very good noise characteristic - 35 dB, which does not require additional sound insulation in residential areas. Despite the low power consumption - 120 W, the water pressure in the system increases by 0.6 - 0.8 bar.

An important specification of the unit is automatic blocking when water flow is less than 90 liters per minute and wet rotor protection (simultaneous cooling and lubrication).

The pump can be installed in both vertical and horizontal positions.

Method #2 - pumping station

If there is no effect from using a flow pump, a more radical measure would be to install a pumping station in the apartment to increase the pressure.

Often only such a forced measure can solve problems with water pressure for residents of the upper floors of high-rise buildings.

Structurally, the storage station consists of a pump and a water accumulator - a membrane tank. The pump pumps water into the tank and then delivers it to the water points

By using pressure switch water is supplied to the consumer with the required, predetermined pressure. When the receiver is full, the pump turns off.

The station resumes operation after the water has been consumed in hydraulic accumulator.

The advantages of such a device:

• the ability to use water even if it is not available in the water supply system;
• resistance to changes in water pressure.

But it should be borne in mind that such units have relatively large dimensions and are noisier than flow pumps. This imposes certain inconveniences in using them in apartments.

In addition, a powerful pumping station can suck air from apartments located on the same water supply risers, which will lead to the pump turning off and the need to fill the system with water.

Pumping stations are more widely used in private houses on autonomous water supply systems.

We have provided recommendations for choosing a pumping station for increasing pressure and a review of the best ten proposals in next article.

Stabilization of water pressure in the system

In high-rise buildings, although less frequently, the problem of not only low, but also high water pressure occurs.

Gearboxes are available for sale, equipped with pressure gauges to monitor the pressure in the system during water tapping and allowing precise adjustment of the water pressure

To stabilize it on intra-apartment water supply networks, protect the system itself with measuring devices and household appliances connected to it from increased pressure, and water hammer Pressure reducers/regulators are used.

Installation pressure reducers It is recommended to carry out this on pipelines immediately after the inlet shut-off device in front of the water supply meters.

Conclusions and useful video on the topic

The video shows how to take water pressure readings in an apartment at three water points:

Video, the author of which offers an accessible way to measure water pressure in a water supply system using a pressure gauge made from improvised means:

Video with tips for proper installation of a circulation pump on utility networks:

Knowledge of the norms prescribed by law for water pressure in an apartment’s water pressure system and the correct procedure for measuring it are very important for the common consumer. This will allow you to argue your legal demands against the management company in case of violations of social standards for water supply..

But most importantly, even if left alone with this problem, following the instructions given, it is quite possible to independently ensure comfortable use of water and protect household appliances and sanitary devices that use water from failures and premature failure.

Have you repeatedly observed low pressure in the water supply network and want to increase it yourself? But do you still have doubts about choosing the best option for increasing your blood pressure? Ask advice from other users and our experts in the comments section.

Or maybe you yourself installed pressure-increasing equipment and now want to share your experience? Write your recommendations, add a photo of your pump/station under this article.