Double Disk vs. Resilient Wedge 3

[Roadwork]

Can anyone provide some insight on the pros/cons of one gate valve over another for water distribution systems? If I remember right, when I worked for a county water utility (along time ago), they almost exclusively specified double disk gate valves in new construction.

 

[rconner]

fyi see

http://eng-tips.com/viewthread.cfm?qid=223891

 

[sjohns4]

I recently redesigned the piping in a booster station to allow the installation of a meter. The existing valves in the station were double disk valves. The out of 4 valves in the station, only three would shut the flow off. The operator told me this was typical of his experience.

Of course, any valve that doesn’t get exercised regularly will become problematic.

 

[greggy]

For potable water, nothing beats the tight shut off, simplicity, and operability of a resilient seated gate valve. Double disk valves are expensive and prone to leaks and mechanical failure in their later years. In larger diameter double disk valves with higher pressure on one side of the gate, a bypass (another valve to go bad) around the valve is required to decrease the torque required to move the gate. RSWs have less moving parts, no groove seat to catch debris, and stay better longer with proper care and feeding.