Does the PSV recalibration test at site necessary for all PSV types

[PDHPP]

Dear All,
I'm a commissioning engineer and have a problem with my client at site regarding recalibration and/or live test of ALL PSVs. The client would like to see PSVs recalibrated at work-shop (before installation) or make a live test, if the PSVs already installed in a package unit like as Chemical-Dosing Stations.
Is there any limitation or definition in the related API / ASME / ANSI standards ?
Which type of PSVs must be checked and which type not ?
Thanks a lot in advance
Hamid

 

[don1980]

API 576 (Inspection of Pressure Relieving Devices) states that all spring-loaded safety valves should be tested before they are put into service. Refer to paragraph 6.5.2. This is a recommendation - not a hard requirement. In my experience, most companies do this.

You mention chemical dosing packaged units. Perhaps you are referring to positive displacement dosing pumps which have an interal relief valve. Those internal relief devices are non-standard devices, and they are not easily accessible or easily serviced by a PSV valve shop. For that reason, they are generally excluded from the pre-start-up testing mentioned in API 576.

 

[e43u8]

I think by "...PSVs already installed in a package unit like as Chemical-Dosing Stations." OP means the external PSV which is normally installed on discharge line of a positive displacement pump to protect the pump and/or downstream facilities against overpressure. Then,if so it is included in the pre-start-up testing mentioned in API 576.

 

[PDHPP]

don1980 and e43u8: Thanks a lot for your reply.