4 replies to this topic

[rohollah]

hi
I work in a petrochemical company.our inspection department has prepared a program for our safety valves calibration.
according to this program each psv must be moved to workshop in order to calibration, once in a year.
is it correct or not?
is there any standard to determine the exact time between two calibration for a psv?

regards
rohollah

[jrtailor09]

Rohollah ,

Do u have safety valve one working & one standby ?

If yes then, I think it is provided with the nozzle for online testing of relief valve. Why it is required to take to workshop ?

One year testing time is correct.

Regards,

[Lowflo]

rohollah - the info you need is found in API 510. I think you'll find that it answers all of your questions regarding setting up an inpection/testing program.

There's no requirement that sets the inspection interval at 1 year. The inspection interval is a risk management decision for the equipment owner to make. The key input variable for determining the inspection frequency is the specific service conditions. If a PSV is in a heavily fouling service, then it might need to be inspected every 6 months, whereas a PSV on a N2 header might only need to be inspected every 10 yrs.

For new process services, for which there is no service history, it's a good idea to start off with relatively frequent inspections (generally folks start at once per yr). Then proceed with extending the frequency based on past inspection results. On the other hand, if subsequent inspections show that a PSV was somehow impaired due to corrosion, plugging, etc, then you need to reduce the inspection interval until that problem goes away - or it may mean there's a fundamental problem with the relief design itself.

[rohollah]

Dear lowflo

Thanks for your explanation.

regard
rohollah

[breizh]

You may have regulation like in China and Thailand to follow .
This will give you the period time , in China it was once a year .

Breizh

Edited by breizh, 01 December 2011 - 07:08 PM.