For flow control which valve is appropiate
For flow control which valve is appropiate
(OP)
For flow control at the outlet of chiller and condenser and at the inlet of cooling tower cells we have been using Globe valve or Balancing valves to set the correct flow across respective equipments.
One of the vendor wants to use butterfly valve as isolation as well as flow control, Is it correct.
One of the vendor wants to use butterfly valve as isolation as well as flow control, Is it correct.





RE: For flow control which valve is appropiate
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RE: For flow control which valve is appropiate
Katmar Software
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http://katmarsoftware.com
RE: For flow control which valve is appropiate
The only reason to use a butterfly valve for any service is installation cost. I find that to be a very short sighted reason to pick equipment since the lowest installation cost is often the highest life-cycle cost when you factor in the cost of lost production while replacing a valve or the cost of extraordinary isolation techniques like "freeze stopple" to get isolation to replace one whos disk has come off.
David
RE: For flow control which valve is appropiate
RE: For flow control which valve is appropiate
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RE: For flow control which valve is appropiate
David
RE: For flow control which valve is appropiate
I have seen butterfly valves used successfully for isolation and control on steam. But this is 30 psig steam in distilleries. You would not use this type of valve as the crown valve on a 1200 psig power boiler, or the control valve to a turbine. But those are not the applications involved in the original question.
I cannot ever remember seeing a globe valve on a cooling water duty. In the old days we used gates, and now we use butterflies.
There is no "one size fits all" in the application of valves and every instance has to be treated on its merits. Perhaps sridhar's application is a very arduous one, but on the face of it I would say it sounds like the correct place to use a butterfly valve.
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: For flow control which valve is appropiate
On land based steam plants the issues are probably less dynamic and a butterfly valve might be the most cost effective answer, I'd have to run the life cycle economics to convince myself of that.
David
RE: For flow control which valve is appropiate
Since you should never have any one of the butterfly valves more than 45% closed, the Cv range is perfect. What happens is that during the year, the operators adjust valves to balance loads and every valve eventually all wind up being partially closed. SO, you go back and reset them open and close just those that require lower flow.
A leaking butterfly on a water system is not a concern. We would slide a paddle in on the exchanger if we needed absolute shut off.
RE: For flow control which valve is appropiate
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