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

Modern life is impossible to imagine without running water in the apartment. Water supply is a complex and multifunctional process, the work of which for normal human life should be provided around the clock and with the required pressure. Although the latter can often cause problems.

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

Supplemented material is illustrated with photo materials and video tips for installing equipment to increase the pressure in the water supply.

Water pressure standards

In the regulatory documents governing the standards related to the water supply system, such parameters as water pressure and minimum free pressure are found.

Values ​​for pressure measurement

In order to correctly understand the standards indicated in the documents, which prescribe the pressure with which water should be supplied to the water supply system of an apartment building, it is necessary to present the relationship of these values.

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

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

Found in regulatory documents pressure indicator means the smallest height to which water is required to be raised, taking into account losses to overcome the resistance of the pipes, above ground level to reach the point of drawing it.

Both of these quantities can pass into each other.

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

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

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

Normative indicators of pressure in pipelines

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

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

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

Decree No. 354 regulates the quality requirements for the supplied utility services, including the setting of pressure standards in residential buildings for hot water supply and hot water supply at sampling points.

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

To do this, 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 on the water intake in the apartment.

Having agreed all these documents with each other, it is possible to derive the basic regulatory values ​​for water pressure.

At the input of a one-story house, the minimum water pressure should be at least 10 m. In an apartment building, 4 m is added to each floor

For example, for a house on 8 floors, the input pressure of water according to the calculations 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 should be provided:

• Hvs in the range from 0.03 MPa (0.3 atm) to 0.6 MPa (6.0 atm);
• DHW - from 0.03 MPa (0.3 at.) To 0.45 MPa (4.5 atm).

No less than what size should be the free pressure of water in the apartment for specific plumbing fixtures having mixers is also regulated by SNiP:

• wash basin - 0.2 at;
• bath - 0.3 at;
• Dushcabin - 0.3 at.

Given the above indicators, when choosing a plumbing fixture, you must pay attention to the value of the minimum pressure at which it is designed to work.

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

Therefore, the devices, the characteristics of which the parameters are specified below the standard, can be talked about as not intended for installation on specific utility networks and to be replaced.

It is necessary to take into account such a nuance - the given building standards determine the admissible possible minimum or limit limits for water pressure, and this allowed range is quite large.

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

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

Methods of taking readings

Theoretical knowledge of the normative values ​​related to water pressure allows us to move on to a practice that provides an answer to the question of how to measure the pressure of water in a tap or other water points of an apartment at home.

Method # 1 - the use of stationary pressure gauges

The main instrument for measuring pressure in water communications is a manometer. There are several types of devices for this purpose, which differ structurally and by the principle of operation.

The most common type of instrument for reading water pressure is a mechanical pressure gauge. It is reliable in operation, has an easily readable scale of values ​​and an information dial

Often the control of the water pressure in the apartment is limited to the readings of the device installed on the border of the cut-off intra-apartment and central pipelines. However, in reality, the readings of such a pressure gauge will be not entirely correct and accepted with some errors.

This is due to the fact that all pressure losses on the elements of the internal wiring of the apartment (filters, tees, valves and control valves) are not taken into account. In addition, bends and sections with a change in the cross sections of pipelines affect the free pressure of water.

Therefore, the best option is to equip with gauges all the inlets of water consumption points in the apartment. It 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 draw-off point in other ways.

Method # 2 - use a portable pressure gauge

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

The application of this method allows you to measure water pressure directly at the inlet of each plumbing fixture, affecting its pressure.

You can assemble a mobile pressure gauge with your own hands, having improved the purchased factory device. For this it is necessary: ​​1 - a conventional water pressure gauge with a scale of up to 6 bar; 2 - threaded extension; 3 — adapter with 3/8 inch 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 a 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 tap on the shower opens.
4. The pressure is measured.

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

If there is no corresponding adapter, then instead of it you can choose a hose with a diameter that allows you to connect it to a pressure gauge. In this case, the connection to the shower hose is through a fitting with a ½ inch thread.

The water pressure during the day can fluctuate, therefore, for the reliability of the readings, it is recommended to measure several times, including during the peak water analysis.

Method # 3 - non-instrument pressure determination

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

For measurements, it is necessary to purchase a transparent PVC hose / tube with a length of about two meters 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 procedure:

1. The hose is connected at one end to a point of disassembly, is exposed and, preferably, is 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 upper hole is hermetically sealed.
4. The water tap opens to the maximum pressure.
5. The height of the water column is measured from the zero level to the lower boundary of the air plug (N).
6. The air plug height (h) is fixed.

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

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

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

Causes of low pressure and prevention

The responsibility to ensure the required pressure in the water supply system of an apartment building is assigned to the organization, the service of which is the house. As a rule, this is a management company, but also, a contract for a water supply service can be concluded directly with the provider of this service.

Therefore, the first thing that needs to be done with a general decrease in water pressure in the house or riser is the established procedure, it is better to inform the responsible organization in writing for taking response measures.

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

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

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

These factors may include:

• malfunctions, in the form of leaks and gusts on utility networks, valves, fittings;
• slagging pipelinesas a result of which their throughput is reduced.

Management company troubleshooting on common-house networks and the 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 the clogging of the water filters

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

The consequences of pressure deviations from the norm

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

With increased pressure, a threat is created:

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

Inadequate water pressure can cause not only domestic inconveniences that arise, for example, when washing dishes, taking a shower, but also a complete refusal to work - in the worst case, some sanitary appliances, gas water heaters and instantaneous water heaters.

The compliance of water pressure in the pipelines of an apartment building with the established regulatory values ​​and standards should 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 normative stipulated requires the determination of the cause of this malfunction and urgent measures to normalize the pressure.

Ways to increase the pressure in the system

The problem with water pressure, especially in old houses, can have a structural and technical character, before which public utilities are powerless. Also, saving energy, suppliers often turn off one or more common-house booster pumps. Due to the duplicate circuits, the water supply does not completely stop, but the pressure in the system is significantly reduced.

In such a situation, it becomes necessary to use one of two or two simultaneously 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 the water pressure without additional intake, and no permits for their installation in apartments are required.

There are several varieties of these devices that differ in such characteristics as:

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

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

Structurally, the 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 belong to surface circulation pumps. They are easily and quickly mounted on existing engineering networks. As a rule, additional reconstructions of the system for installing flow pumps are not required.

The pressure pumped by the pump can be regulated both in manual and automatic mode.

At pump selection it is necessary to compare its performance with water consumption in the apartment, so that while using several household appliances consuming water, the unit's capacity is enough for their normal operation.

For example, a pump with a capacity of 3.5 m will be enough for three points of water analysis³ /hour.

Small in size and weight, flow-through circulation pumps can be installed at the entrance of the central line to the apartment, as well as directly in front of the water-consuming plumbing appliance or gas boiler

Among the most popular models of units for this purpose, one can single out a device from the Belgian manufacturer Grundfos UPA 15-90, which has a large 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 premises. Despite the low power consumption - 120 W, the water pressure in the system rises by 0.6 - 0.8 bar.

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

The pump can be installed both vertically and horizontally.

Method # 2 - pumping station

In the absence of the effect of using a flow pump, a more radical measure will be the installation of a pump station in the apartment to increase the pressure.

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

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

Via pressure switch water enters the consumer with the required, predetermined pressure. When the receiver is full, the pump shuts off.

The work of the station resumes after running out of water in accumulator.

The advantages of such a device:

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

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

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

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

Recommendations on choosing a pumping station for increasing pressure and an overview of the top ten proposals we gave in next article.

Stabilization of water pressure in the system

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

Reducers are available for sale, equipped with pressure gauges for monitoring the pressure in the system during tapping and allowing fine tuning of the water pressure

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

Installation pressure reducers It is recommended to produce on pipelines immediately after the input shut-off device in front of the water meters.

Conclusions and useful video on the topic

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

The video, the author of which offers an affordable way to measure the water pressure in the water supply system using a manometer made from improvised means:

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

Knowledge of the norms prescribed by law for water pressure in the apartment’s water system and the correct procedure for measuring it are very important for a simple consumer. This will allow arguing their legal requirements for the management company in case of violations of its social standards for water supply.

But most importantly, even being left alone with this problem, following the instructions given, it is quite affordable to independently provide comfortable use of water and protect household appliances and sanitary-technical devices that use water from failures in work and premature failure.

Do you repeatedly observe a weak pressure in the water supply network and want to increase it yourself? But you still have doubts about choosing the best option for increasing pressure? Ask for advice from other users and our experts in the comments section.

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