Thanks to all for your help.
I am trying to understand the cause of the failure rather than just change to another type of valve/liner etc (due to the 12month period before I know if the change has been successful).
Therefore some more info.
The flowrate is 800-1000 litres/min
SG's range from...
I have a problem with some 3 inch butterfly valves. The body is made from polypropylene, with a butterfly made of HDPE. It contains a circumferential nitrile seal.
The system pumps wine up to a dynamic pressure of 80kPa. The valve is tested to 100kPa and passes. However, after approx 12...
