Water pressure reducer in the water supply system: purpose, device, adjustment rules
The water supply system consists not only of pipes that carry out the transportation of water to the supply points. It includes devices and mechanisms to stabilize the operation of the pipeline.
One of these elements is a water pressure gear in the water supply system. the device solves problems associated with changes in the pressure of the liquid. It is differently called the reduction valve.
We will figure out in what cases the gearbox must be used, how the device works, and what are the design features of different modifications. In addition, we describe the installation technology and give an example of adjusting the reduction valve.
Water pressure reducer principle
The gearbox is a regular valve with a spring drive. In effect, it is driven upon a certain pressure mark in the water supply. Due to the regulation of the opening width of the valve, the pressure is normalized.
The gearbox is installed in the following cases.
- Too low water pressure in the water supply. The jet from the mixer is very weak, which causes certain discomfort when using it (or the bath has to gain too long). In this case, the system with the gearbox is supplemented by pomp, which increases the speed of watercress. Even with low water pressure, a “automatic” type washing machine may not work: with too low, the powder is not washed out fully from the tray.
- Unstable water pressure. When opening the crane, a powerful stream is obtained, which after 5. 10 seconds significantly weakens. Adjusting the watercock of optimal temperature (mixing hot and cold water) in this case it is difficult. The gearbox allows you to solve this problem.
- Too high pressure in the water supply. Most often, residents of the first floors of a large number of robes are faced with this phenomenon. If there is only one riser in the entrance, then overestimated pressure is made in order to provide the upper floors with water.

The gearboxes are also installed to protect devices connected directly to the water supply: boilers, washing machines, running water heaters, dishwashers, hydromassage boxes.
The arrow indicates the direction of water movement. If you install it incorrectly, then the gearbox will work as a shut.off valve

How and where to put a reduction valve for water
The issue of installing the valve remains debatable, although everything is clear to the specialists.
Firstly, “how”, unless otherwise specified in the instructions, then you can install the reduction valve on horizontal, vertical and inclined areas of water supply. However, it is impossible to put it “upward”, the spring valve spring cannot work in an inverted state.
Secondly “where”. I repeat, the task of the water reducer to reduce the pressure of water in the system, and not become a damper. It can reduce water pressure, both for the entire system and for a separate device (for example, a boiler or shower).
- reduce the pressure of the static (closed) system for all valves and mixers in the apartment;
- regulate the pressure on the output of the dynamic system when water is consumed.
It is important to note once again here, not all gearboats can immediately perform two listed tasks. Gearboxes that not only lower, but also maintain pressure in the system are much more expensive.
Where to put a pressure gear in the apartment?
So, for the entire apartment, the gearbox should be placed immediately after the pair of the input overlapping valve with a rough cleaning filter (watch the circuit).
On the valve body there is an arrow indicating the direction of water movement. This must be taken into account when installing.
How to Install a Water Pressure Reducing Valve | This Old House
Tips for choosing a valve model
As mentioned above, water heaters go on sale with a safety valve. In this regard, when buying a new model, especially branded, you do not need to take care of the selection.
The need for purchase arises in three cases:
Knowing the boiler model, you can easily select a new element. In the instructions for the operation of equipment, you can find parameters of the maximum pressure. the same should be knocked out on the case of a new part.
A valve with a lower value of maximum pressure or, on the contrary, a product with a margin does not need to buy. In the first case, you will observe a constant leak from the tank, in the second. the valve simply will not work when an emergency arises
The diameter of the thread should coincide with the dimensions of the mounting fitting and the pipeline of the CVS. In addition to the device itself, you will need a linen thread on a pipe or rubber gasket if a flexible eyeliner is used.
Sometimes a valve is installed between the boiler pipe and the fuse to drain the water. This is a permissible, permitted binding scheme, but on one condition. the valve must be mounted on a horizontal withdrawal from the highway of water supply. No locking devices between the safety valve and the water heater should not be.
Features of choice
Adjusting the water pressure reducer in the water supply system allows you to prevent hydraulic boards, selected taking into account:
- permissible pressure loss in the range with a small water removal from 1 to 2.5 bar, and with a large water consumption from 4 to 7 bar;
- bandwidth within the limits for a private house from 0.1 to 0.15 m3/h;
- internal diameter. usually mount a water pressure gear with a passing cross section from 1/2 to 1/4 inches;
- connection method. through carving or flanges.
Owners of residential facilities must be installed by a water pressure regulator in the water supply system, the adjustment of which prevents the formation of watercomers. Thanks to their absence, the work of plumbing devices, washing machine and other similar household appliances will not be violated. In addition, the gearbox does not make noise and even save money, because after installing it, water consumption will decrease.
Protection from the accident
The water pressure above the maximum for the boiler can lead to a gap or crack in its case. Should we talk about what financial and moral costs this can lead. Especially if the neighbors from below only made repairs.
The manufacturer of boilers may refuse warranty service if he finds that the product breakdown occurred due to increased water pressure and there was no water pressure reducer for the boiler in the system.
Is it possible to install a water pressure reducer vertically: features of the installation work
The installation of a water gearbox is recommended to be performed on a horizontal pipeline. At the same time, the manometer of the device should be vertically. However, sometimes cases are allowed when the gearbox is installed in vertical sections of the pipes. Before installing the device, it is necessary to install a filter that provides gross cleaning. If this is not done, then small grains of sand and dirt from the water will fall into the inside of the gearbox. The life of the device, while decreasing several times.
Installation of a water pressure regulator in the system is comparable to the installation of the counter itself. It is initially necessary to block the water and cut part of the pipe. Next, the locking valves are installed, with which, if necessary, water is blocked. The regulator is installed strictly vertically. Use fumlant to compact connections.
The gearbox is installed behind the counter, a valve with a filter is mounted between them. After installation of the gearbox, the second valve is installed. With the help of valves, it is possible to control the condition of the pressure reducer and carry out its dismantling, if necessary.
Next, you should set the gearbox. The first entrance valve must be opened, and the second is closed. To increase and reduce pressure by a special key, it is necessary to rotate the adjustment screw. In order to work correctly and efficiently, periodically clean it from dirt and check its condition.
The position of the water gearbox during installation
The reduction valve can be installed horizontally and vertically. The only restriction. He cannot be mounted in an inverted position. The setting spring can be directed up, to the right, left, but not down.
Consider the ICMA ICMA options for the reducer installation. Actually, they cover practically options that may arise with apartment owners.The following conventions are used in the schemes:
Hydronic Boiler Feed Line Build
All this reinforcement is presented in our store.
Option 1
Horizontal connection of the counter and gearbox.
Option 2
Connection of the meter horizontally, the reduction valve of the water. Vertically.
Option 3
Connection of the counter is vertically, the gearbox is horizontal.
Option 4
Horizontal connection of the gearbox without a water meter.
Option 5
Vertical connection of the gearbox without a meter.
Recommendations for operation
During the operation of the gearbox, it is necessary to pay attention to the stability of the pressure of the water. The presence of differences indicates a malfunction of the membrane.
If there are any malfunctions in the work of RDV, it is necessary to dismantle and disassemble the structure. Preliminary it is necessary to block the water supply at the input.

So, the gearboxes are designed to stabilize the water flow in order to protect the pipeline and the equipment connected to it from high pressure. In addition, they reduce water consumption and reduce noise in the water supply system.
Incorrect selection of the device, the assumption of errors in the process of its installation and settings can lead to the opposite result and provoke an emergency situation. The recommendations given in this article will help to avoid these problems.