Valve Selection
In the pipe system, valve serves the purpose of controlling, and because of different structure and materials, valves are produced in a variety of valve types. In order to make sure the pipe system achieve in most efficient, cost-effective and long service, valve selection is very important.
1. Valve Function
The valve has four principal functions:
a. Opening and shutting off the flow
b. Regulating (throttling) the flow
c. Preventing return of the flow
d. Regulating or relieving the pressure of the flow
2. Pipe System Main Factors
a. Pressure or class rating
b. Pressure
3. Medium type
a. Liquid
b. Gas, steam, air
c. Dirty
d. Corrosive
4. Medium flow
a. On-off throttling
b. Non-return
5. Flow velocity
6. Operating conditions
7. Condensation
8. Frequency of operation
9. Space available
10. Manual or automated control