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Backflow preventer and check valve difference, check valve and backflow prevention

Label: reverse flow, prevent, check valve, differential add time: May 25, 2021 click 1293 second

Backflow preventer and check valve are two common concepts in the fire industry. Literally speaking, both of them are used to prevent the backflow of medium and force one-way flow, but for the relationship between the two Hebei personnel examination Central network, most beginners are a little vague. First of all, the definitions of them are briefly introduced
Check valve: also known as check valve or check valve Baidu SEO In order to prevent the backflow of medium, the valve disc should be opened and closed actively. Backflow preventer: an assembly consisting of check-in components to prevent backflow of water supply pipe
The difference between the backflow preventer and the check valve is difficult to find out from the definition alone. The differences between the two are compared in terms of structure, function and location.
I. The structure of backflow preventer and check valve is different
1. Check valve: single check sealing mechanism
2. Backflow preventer: two check valves + drain
The function of backflow preventer and check valve is different
1. Check valve: it is important to ensure one-way flow of medium and prevent backflow of medium. However, it has no antifouling performance. When the check sealing surface fails, it can not be used to prevent the backflow pollution of medium.
2. Backflow preventer: to prevent the backflow of the medium (even if all possible internal seals fail, it can still ensure no backflow pollution accident), and prevent the upper and lower media from contacting.
3. The position of backflow preventer and check valve is different
1. Check valve:
① Wet alarm valve group
② Inlet of deluge valve
③ Fire pump outlet
(4) outlet pipe of high fire water tank
⑤ Water pump adapter
(6) liquid inlet pipe, liquid phase return pipe and gas phase return pipe of LPG storage tank
(7) outlet pipeline of LPG compressor
(8) on the branch pipe of ventilation and air conditioning system
2. Backflow preventer
(1) the fire pump outlet pipe pumped from the municipal pipe network
(2) on the outlet pipe of the fire pump in series
Generally speaking, the backflow preventer can realize the function of check valve, otherwise, it is not true.
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