testing seats in trunnion valves

[ezepecker]

Hi,
according to API608 trunnion valves shall have a test plug to test seats. So I'm wondering how to test a seat. Is there anyting I have to look at?
Thanks in advance.

 

[gerhardl]

Oh yes! Relevant valve test procedures according to the plant or local authorities or end user, which again should refer to the international recognized authorities standard tests.

Also relevant for fluid application type and pressure. Emissions through stem sealings?

Even if the valves are produced to the API requirements local end users could require tests according to other standards, depending where you are in the world.

If tested mounted in pipelines other procedures may prevail.

If you are the buyer, buy valves already factory tested, and if overhaul include tests in your inquiry / specification for overhaul.

 

[ezepecker]

Thank you gerhardl.
But where can I find these tests? I need to do a periodical check of valves already installed. Does any API about this subject exist?
Thanks in advance.

 

[najem86]

i just want to share how seat test is done coz we often make a test pressure for the offshore valve.regarging API standard usually we make low test pressure or hydro test and depend on the valve characteristic.

for the seat test we only focus on the inlet n sometime we dont have to flange the oulet.its depend on the customers required.hence seat test can be done easily.

 

[rneill]

As a start you can look at API 598 "Valve Inspection and Testing". As mentioned by gerhardl, many end users have their own test standards that go beyond the requirements of API 598.

There may also be some testing requirements specified in the standard to which the valve is made (e.g., ISO, CSA, etc.) that you could reference. The valve standards published by API just reference back to 598.

 

[ezepecker]

Thank you,
I appreciate very much your help.