Hello ,
In our plant, we have a pressure control valve PCV installed on the boiler feedwater line to reduce pressure from 70 bar to 5 bar. This valve experiences frequent failures, particularly during plant startup, where the diaphragm is often damaged. As a result, we've had to rely on isolating valves to control pressure, which is not an ideal solution.
The concerned about the root cause of these failures and are exploring alternative valve types that can reliably handle the high-pressure.
Could please provide insights into potential reasons for not reducing to the required pressure 5 bar and suggest suitable replacement valve types?

BR

 

@HHASN,

It would really help if you would provide more details about the device and it's actuator (you mention a diaphragm, so we could guess that it's a pneumatic actuator, but we could be wrong--without details).

 

@HHASN,

It would really help if you would provide more details about the device and it's actuator (you mention a diaphragm, so we could guess that it's a pneumatic actuator, but we could be wrong--without details).

WTF Thank you for your reply
You mean you need data sheet for valve or information about diaphragm?

 

@HHASN,

"It would really help if you would provide more details about the device valve and it's actuator ..."

Valve Manufacturer
Actuator Manufacturer
Device (Valve AND Actuator) Data Sheet(s)

A photo of the device (Valve AND Actutor) would be helpful.

If I posted for help with my watch and you were knowledgeable about watches and I wrote, "My watch isn't working, what could be the problem?" how would you respond? Would you need to know if the watch is analog or digital, if it had been would recently or had the battery replaced recently, if all the hands were working or all the elements of the watch display were working properly, if the watch had gotten wet--possibly even submerged for some period of time maybe at a deep location?

What you've done above is very similar. We only know you have a pressure regulating valve which is failing actuators and being unreliable. That's ALL you told us.

Me? I'm guessing the valve is not the correct valve for the application. A good way to verify that would be to establish contact with the manufacturer, describe the situation and the valve (providing the valve nameplate data--at a minimum the model number and size and temperature of the feedwater during normal boiler operation and during start-up--perhaps a picture, even) and see what they respond/recommend. Specifically ask to speak with one of the manufacturer's application or service engineers.

OR, call a local valve supplier and have them come and have a look and see what they say (there may even be a valve supplier that sells the valve you are having the problem with and a knowledgeable sales representative and/or application engineer who could help with assessment and troubleshooting).

But, just saying, "It's broke; how do I fix it and what do you recommend?" without any other information--well, that's not going to get you any meaningful responses--except the two paragraphs above.

Blessed day!

 

Data sheet

 

Data sheet

Was wondering about problem of diaphragm failure. From specs , It looks like A PRV rather than control valve, One solution could be to use a regular control valve with hardened micro flute trim, due to high pressure and required low CV. Other solution could be to consider self regulating PRV which is similar to control valve but without requiring pneumatic signal for control valve. Emerson , Measoneilan are some of the reputed vendors for these types.
Thanks

 

I understood you mean Actuator's Diaphragm has had high failures during startup. Burden pressure to this diaphragm is 70-5=65 barg at feed water temp 100 Deg.c cause it failure frequently during transition from cold to hot media. Suggest to use Pressure TX. with Globe control valve( EQ% type) is one solution to avoid damage of Diaphragm. I believe Production loss 's cost to your Boiler is higher than replacement cost as mentioned.

 

Was wondering about problem of diaphragm failure. From specs , It looks like A PRV rather than control valve, One solution could be to use a regular control valve with hardened micro flute trim, due to high pressure and required low CV. Other solution could be to consider self regulating PRV which is similar to control valve but without requiring pneumatic signal for control valve. Emerson , Measoneilan are some of the reputed vendors for these types.
Thanks

Thank you for reply , how can i contact with you ?