2 replies to this topic

[Monkichi]

All,

 

I had a question in regards to the use of either diaphragm valve vs. butterfly valves in an ion exchanger water treatment service. We have a WAC and an Ion Exchanger and both are currently using diaphragm valves to control regeneration / backwash cycles. WAC is the new system that provides BFW to one unit while the ion exchanger is older and providing BFW to a different unit.

 

My objective is to replace the piping to the ion exchanger unit which includes the control valves. Since existing WAC control valves are diaphragm valves and we haven't had any major problems with it, I wanted to continue to use diaphragm type valves in the Ion Exchange system. If it is not broken than don't fix it, right?

 

Anyway, someone recommended going towards the butterlfy valve instead because their justification was that the leakage rate is better and it is cheaper. Since it is a water service I don't think leakage rate is a concern and based on my research on this forum butterfly valves do not provide good tight shut off anyway (contradicting the recommendation).

 

Does anyone have any experience in this area to provide advice?

 

I currently graduated last year so my knowledge is fairly limited.

 

Any comments will help.

 

Mike.

 

 

[augusto]

Dear Mike,

 

PFA Teflon lined and elastomer lined butterfly valves provide tight shut-off and zero steam leakage for all type of process applications and are very suitable for Water Treatment in general. Generally speaking Diaphragm Valves are old fashion today.

 

Rgds., Augusto SAVIO

[Monkichi]

Augusto,

 

Thank you for your response. From a cost perspective, how do these butterfly valves compare to diaphragm valves?

 

I was told that certain specialized butterfly valves provide tight shut-off but you will be paying a premium for them.

 

Mike N.