The water pressure regulator in the water supply system automatically reduces and maintains a constant pressure in the consumer’s network. The operation of the device does not depend on the water flow and the initial pressure in the main (distribution) pipeline. The need to install a regulator for domestic and drinking (hydrostatic pressure at the lower point of the water abstraction more than 45 m) and separate fire water supply (pressure in the lower fireplug more than 90 m) is noted in the regulatory literature.
Note! The regulator is installed on the input to the microdistrict, building, sectional riser of a residential building with a height of more than 40 m or an apartment.
The use of water pressure reducers in water supply systems
The device stabilizes pressure and flow in centralized, distribution and autonomous networks of cold water supply. The reduction of parameters is necessary for the operation of technological commercial and domestic hydraulic equipment. In addition, the reducer suppresses hydraulic shocks, eliminates the risk of formation of cavitation zones in pumping equipment, reduces the level of vibration and noise.
The use of regulators in cold water systems:
- utility and technological water supply networks;
- fire extinguishing systems and fire water supply;
- booster pump installations on the main water supply networks;
- water stations;
- irrigation and land improvement systems.
Classification of pressure regulators (general specifications):
- working body – piston, valve;
- actuator – spring, membrane;
- control method – electronic, mechanical;
- throughput capacity – household 0,5? 3 m ?, commercial 3? 15 m ?, industrial more than 15 m ?;
- body material (cast iron, nickel-plated or chrome-plated steel, brass);
- fastening method – thread (from 15 to 50 mm), flanges (from 50 to 450 mm);
- temperature and type of working environment – cold water with a temperature of 0? 40 ° C;
- case diameter, thread pitch, flange standard.
The device is placed at the input to the microdistrict (building), behind the stop valve of the water metering unit or step-up pumps. Different models of the gearbox adjust the head in the direction of flow in the line, before or after the installation of the regulator.
A device in which the degree of opening of the valve is directly proportional to the pressure deviation relative to the tuning parameters is called the water pressure reducer in the water supply system.
Before the regulator of large diameter is mounted coarse water filter. After the regulator, a shut-off valve is installed for maintenance, repair or replacement of the device. Adjustment and visual monitoring of the operation of the device is carried out on the manometers, which are mounted on the pipeline before and after the regulator.
The method of choosing the device takes into account the capacity (flow, m? / H) and the allowable pressure loss (bar) in the case. Local resistance should not have a critical impact on the operation of the water supply system.
The interval of the adjustable setting depends on the degree of compression of the spring and the sensitivity of the material of the membrane. The regulator, equipped with a single spring, has one pressure setting range. Devices with a set of springs of different rigidity, respond to the operating conditions of the system more accurately. The optimal position of the operating pressure of the regulator is the middle third of the regulation range.
The reason for the noise during operation of the device is cavitation, which occurs due to exceeding the permissible flow rate at the inlet to the regulator. The optimal value of the speed of the flow of 3 meters per second. The narrowing of the flow area between the valve and the seat increases the risk of cavitation zones in the gearbox housing.
Important! When selecting a regulator, it is necessary to pay attention to the cavitation coefficient and the recommended speed in the inlet nozzle, which are indicated by the manufacturer in the instrument passport.
Below we consider the devices of the following water pressure regulators:
- lever flange regulator;
- domestic water pressure regulator RDV;
- direct acting water pressure regulator;
- electronic water pressure regulator;
- water pressure reducer Honeywell.
The hydraulic lever device of direct action maintains the set pressure before and after the installation site or regulates the flow (pressure drop).
Structural elements of the regulator:
- housing (cast iron, steel);
- cover with gland device;
- stem with two valves;
- leverage system with cargo and supports to maintain access control;
- diaphragm actuator.
The models of lever regulators “before” and “after themselves” are distinguished by the position of the working body relative to the saddle. Valves that open the passage under the action of the load, are designed to adjust the pressure after the installation site. In the gearbox, which reduces the pressure before the installation site, the valve closes the passage in the saddle under the action of the load. Adjusting the pressure of the regulator includes calculating the mass and selecting the location of the load on the lever.
Industrial, commercial and domestic pressure regulators of the WRD brand are produced by a Russian manufacturer of safety plumbing fittings Pascal LLC from Tatarstan. Household water reducers help reduce pressure, noise and vibration, increase the service life of hydraulic equipment of pipelines and valves. The installation of regulators WFD reduces energy consumption, saves the cost of municipal water supply.
The pilot-type flanged valve is distinguished by the design of the RFE, an industrial water pressure reducer. The principle of operation is to reduce and maintain a given pressure mode using the energy of the network flow.
The design of the device RDV 150-1G:
- housing with flanges (input-output);
- guide bushings and stem;
- main valve;
- pilot valve body with mechanism and diaphragm (main valve control component);
- pulse tubes.
With increasing pressure in the pipeline above the setting value, the pulse flow of water through the tube tends to the body of the pilot valve. The spring-loaded element opens the channel, the medium enters the chamber above the diaphragm. Curved membrane overlaps the flow area of the regulator. Reducing the pressure in front of the valve returns the spring to its original position, the membrane opens the passage of the device.
An electronic device (press control) starts up a low-power pump if water is taken from the system. The silent mode of operation allows you to use the device in an apartment, private house or at the cottage. The electronic sensor prevents operation of the pump without water, prevents water hammer, responds to incorrect pressure and flow rates.
The inlet on the housing allows you to install a regulator on the pump housing or in the water supply line. Installation is made to the first point of the selection of water. The working (installation) position is always vertical. The direction of the arrow on the body follows the direction of flow of water. The check valve is mounted in an electronic regulator. Before turning on the device pump is filled with water.
The design of the electronic controller:
- plugs from technological polymer for connection of a cable;
- inner diaphragm (EPDM);
- electronic board in a special flame retardant casing.
The starting pressure (1.5 bar) is set by the manufacturer. The nominal pressure of the pump must exceed the starting value of the gearbox by 0.8 bar. Changes in the tuning parameters are made as necessary, depending on the operating conditions of the pump. The starting pressure setting regulator is turned with a screwdriver.
Important! The nominal pressure of the pump must exceed the starting value of the electronic gear by 0.8 bar. Press control set in the event that the water circuit of the system does not exceed 15 meters.
Honeywell Water Pressure Reducer
Household water pressure regulator brand Honeywell 1/2? lowers the excess pressure in the water supply system, maintains constant parameters of the network, allows the economical use of water. Stable pressure through the flow area provides a silent mode of operation of the device.
Prices for domestic pressure regulators for cold water supply differ from the cost of imported instruments. Competition manufacturers affect the range and properties of the proposed product. Domestic counterparts of foreign safety valves are inferior in terms of design and operating comfort, not at the expense of the quality of regulators.