Gear Pump

[a1987]

Dear Sirs
i have received some process data sheet for gear pumps. i have notice that in three of ten data sheets is not expressed at what pressure is set internal relief valve...

in your opinion why is not defined set value for internal relief valve of this three pumps??
is this a value that process have to indicate? do i ask for this value at my process department??

best regards

 

[LittleInch]

It's probably an over sight, but depends on what the system is that the pumps are connected to. If they have a common or individual pressure relief or bypass set-up already included in the pipework dwnstream of the first isolation valve then you don't need one in the pump itself.

Just ask the same question and hopefullly you'll get a sensible answer.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[a1987]

ok thank you for the answer!!

at the same time i think that the presence of internal relief valve doesn't involve the assence of PSV on the recirculation line..

in my opinion the second one is a protection for the line, infact is set in function of the line rating.

do you agree?

 

[Pumpsonly]

You are correct. The external PSV if, used is usually determine by the pressure rating of the piping system.
The internal or integral relief valve set pressure in the pump is usually determine by the pump vendor to protect the pump
or preventing the motor from overloading due to a closed discharge valve.

In the absence of internal/ integral relief valve,the external PSV must be installed before the discharge valve.