Maintenance and management of pressure reducing valve

1. Dirt and sundries must be avoided in the pressure reducing system of the pressure reducing valve. Sand, hemp and sundries may be left behind in the pipeline network of decompression system of newly-built or rebuilt projects. Before it is put into operation, it should generally be washed with water. After meeting the cleaning requirements, finally install the pressure reducing valve and filter element to prevent sundries from flowing into the pressure reducing valve and preventing the pressure reducing valve from being stuck. After the system enters into operation, ensuring the smooth water flow in the pressure relief system is closely related to the circulating ability of the filter installed on the system. If the filter element is seriously adsorbed by sundries, it will affect the work of the pressure reducing valve. Therefore, it is necessary to check the filter regularly to remove pollution in time. Practice shows that this work must be done every two to three months. Some adjustable (spring-type, diaphragm-type) pressure reducing valves have their own filters in the main valve or pilot valve, and the filter elements need to be disassembled and cleaned regularly.

2. 1 1 The prepared pressure reducing valve group shall be rotated regularly. The pressure relief system of domestic water supply pressure relief valve in high-rise buildings is mostly located in vertical water supply zones, generally located in the main pipeline of each water supply zone. Considering the reliability and safety of water for many users (there are dozens to hundreds of households in each community, and each community has dozens of rooms for hotels, restaurants and other public buildings ...), two sets of pressure reducing valves should be installed in parallel during design (1 standby). Gate valves or butterfly valves are arranged on both sides of the decompression channel, which can open and close any decompression channel. In order to make the two parallel decompression channels work normally, they are exchanged in turn once a month. If the decompression channel is left for too long, the stagnant water will scale and the valve core of the decompression element will be stuck and fail.

3. The gas accumulated in the pipeline should be eliminated in time. When air enters the decompression pipe network or changes with the pressure in the pipe network, gas and water are separated, and the water pressure of users in the area is extremely unstable; At the most unfavorable water supply point, the pressure suddenly changes, sometimes there is a false peak pressure, sometimes the water is pumped away, and the pipe network will be accompanied by a collision sound. This phenomenon will affect the stable work of gas water heaters and electric water heaters, and will be destroyed in serious cases; It also has great destructive power to the water inlet connecting pipes of various sanitary wares, so tube explosion incidents occur from time to time; Some water meters are inaccurate, and when users don't use water, the water meters will keep turning. In order to prevent such accidents, it should be checked whether the water storage elevation of the main domestic water supply pipe of the roof water tank meets the requirements. If it is not satisfied, water vortex will appear at the outlet of the water tank and air will be sucked in. Troubleshooting can adjust the minimum water level of the liquid level controller in the water tank. Experience shows that the general minimum water level should be no less than 0.3m from the outlet. You can also repeatedly open the pressure gauge deflation cocks on both sides of the partitioned decompression system to slowly discharge the air that has entered the pipe network. If the above measures are taken, the above phenomenon still occurs in some water users below the tip of the main pipe in the residential area, and automatic exhaust devices can be installed in these parts.

4. Pay attention to the pressure relief system of the pressure relief valve. No matter whether proportional pressure reducing valve or adjustable pressure reducing valve is selected, the pressure reducing ratio P 1∶P2 should not be too large, but should generally be controlled within 5∶ 1. Exceeding this range is easy to cause cavitation, damage valve parts and produce howling noise. For some piston-type pressure reducing valves, the manufacturer processes a small hole with a diameter of about 1.5mm on the valve body, and its function is to let the valve core play the role of inhaling and exhaling when moving. Care should be taken not to block the small hole during maintenance and management, otherwise it will affect the normal work of the pressure reducing valve.

5. Strengthen the management patrol of the safety system of the safety valve, and pay attention to the working dynamics of the safety valve itself. The pressure values before and after the valve are close, indicating that the pressure reducing valve itself is faulty. That is, the plane sealing rubber between the piston pressure reducing valve core and the valve body is damaged; The diaphragm of the main valve of the diaphragm-adjustable pressure reducing valve is cracked, the O-ring is damaged, and the connecting pipe of the pilot valve is blocked, which leads to the weakening or failure of the pressure reducing function of the pressure reducing valve. This is extremely harmful to the residential pipe network, especially many water-using equipment may burst under overpressure and must be repaired in time. If the small hole on the valve body of proportional (piston) pressure reducing valve keeps leaking, it means that several O-ring seals on the valve core have worn out and should be replaced. However, when repairing and disassembling the pressure relief element, be careful and replace the internal seal; When cleaning up sundries, we should make the best use of the situation. Do not pry the moving parts of the valve with metal bars and hard bars. Knock the vibration with a wooden hammer and handle, and slowly remove the internal parts of the valve. When reinstalling after repair, it must be consistent with the flow direction indication on the valve.

6. Pay attention to check the installation position of proportional pressure reducing valve. Improper design and installation of pressure relief valve in high-rise building will lead to high and low pressure behind the pressure relief valve, serious deviation of pipe network pressure from the allowable range, shower damage, water pipe burst, water meter damage and other accidents. Sometimes the water flow is not smooth, and the partition has irregular water cut, which affects the user's water use. If a similar accident happens, check the whole water supply system in the decompression area of the pressure reducing valve, which can be found without doubt; When removing the filter and other parts of the pressure reducing valve, there is nothing unusual; Some property management units even doubt the technical performance of the pressure reducing valve, and often replacing it with a new one can't solve the problem. At this time, you can check whether the design and installation position of the proportional pressure reducing valve is reasonable, and carefully check whether there is equal inverted siphon phenomenon in the pipe network system, that is, whether the elevation of the output pipeline of the partition is similar. This situation is easy to appear in the same roof water tank and water supply system of the main and auxiliary buildings. When these problems are found, we can consider raising the installation position of proportional pressure reducing valve to a higher level (not too high, we must consider the pressure-bearing specification requirements of water equipment in the whole region); The main and auxiliary buildings can also be equipped with two independent proportional pressure reducing valve water supply systems.