High Pressure valves for Potable Water Use

[torq6]

I recently requested quotations for very high pressure (~600 psi) gate valves for use with potable water. Most companies replied that they could not quote because their valves for these pressures did not have the protective epoxy coating in accordance with AWWA C550. I, however, received one quote on some "cast carbon steel gate valves flanged and drilled to BS4504 metric PN40." I called the supplier to verify if the valves were suitable for potable water use and mentioned the refusal of other suppliers to quote due to the absence of the epoxy lining. He replied that the operating pressures I was dealing with are not usually encountered in potable water applications thus valves for these pressures would not be expected to be to AWWA specs. He added that I would not get valves at these pressures with the epoxy lining and would have to make do with the carbon steel valves as is. I would like to know what would be the implications of using the cast steel valves for potable water. Thanks.

 

[dicksewerrat]

rust . why 600 psi?

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[torq6]

This is for a gravity flow water system in Dominica, the Caribbean's most mountainous island. The water must come from very high elevations, come down to sea level, travel along the coast and then go back up to various storage tanks at high elevation, thus the high pressures. At present, AWWA valves are being used but these have to be changed regularly due to damage from these pressures.

 

[dicksewerrat]

The uncoated valve will work as long as you operate them often.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[joetbear]

There are companies that make stainless steel valves of that pressure and size, that would take care of the both of you needs.

 

[JStephen]

Look at steam valves?