Points Should Be Considered When Installing Gas Valves

Gas valves are a type of compulsive sealing valves. Nevertheless, when closing valves, pressure should be applied on disc in case of leakage in compulsive sealing. When medium enters into body through the bottom of disc, resistance which should be overcome is the thrust caused by friction between stem and packing and the pressure of medium. The pressure used for closing valves is larger than that used for opening valves. So, the diameter of stem must be large. Otherwise, stem may be bended and result in obstacle.
 
Points need to be considered when installing gas valves:
 
(1)    Bellows check valves operated by handwheel or handle can be installed at any position in pipe.
(2)    Handwheel, handle and actuator cannot be used for craning.
(3)    Flow direction of medium should be in accordance with the direction of arrow marked on valves.
 
Gas valves also called as check valves are one of most commonly used valves. They are popular, because they have advantages of low friction between sealing faces when turn on or off, long service life, low height, easy manufacturing and convenient maintenance. Gas valves are not only suitable for medium or low pressure, but also suitable for high pressure. Its closure principle is that depend on pressure on stem to make sealing face of disc to seat the sealing face of seat and stop medium from flowing through.  
 
Gas valves allow medium to flow in only one way. They have directivity when installed. Their face-to-face dimension is larger than gate valves. Meanwhile, they has less reliability of sealing for high fluid resistance when long-time running.
 
Gas valves are classified into straight-through check valves, angle check valves and straight-flow check valves. 
 
Points Should Be Considered When Installing Gas Valves