Valve testing in high temperature

[GB67]

Hello

do anyones know an intenrational standard for valve testing in high temperature for metal seated valves?

Both API 598 and EN 12266 specifiy fluid temeprature between 5°c and 50°C

Then I expect that the leakrates specified in API 598 cannot be applied also at high temperature test. I'm wrong?

(Note: I'm not speaking about fire test)

Thank you

bye

 

[valvit]

API 6A PR2 test specifies 20 cycles at both minimum and maximum rated temperature.

Valvit

 

[bcd]

There is no international standard for high temperature leak testing of valves. They do not exist because they are not necessary. Leak testing per API-598, ISO-5208, etc. is a quality check. Confirms the valve was built correctly. If you need a high temperature leak test to confirm the valve will not excessively leak in your process, this is not a quality check. It is a test of the specific valve design and needs to be performed in a laboratory. You will need to define your test parameters and your allowable leak rates.

 

[Danlap]

Hi GB67,

Align with bcd, there is no international standard for high temperature testing. You need to define the test parameter by referring to several standards and create your own test requirement. example such as ISO 15848-1 for Fugitive Emission testing, ASME B16.34 for what testing pressure should be applied @500 degree Celcius, what is the heat rate to be applied on the valve (normally after 200 degC, ones should apply 100 degC/hour for heating up the valve), etc.

Then I expect that the leakrates specified in API 598 cannot be applied also at high temperature test? Yes, you can expect this result (Class B tightness for new Metal Seated valve).
And maybe No for some low-tech valve

I personally think this is necessary depending on its criticallity to proof test its design concept since valve may have different "behaviour" when introduced to high temperature (assuming this represent your actual operating temperature), such as:
Note that high temperature test should be combined with multiple cycle of the valves
a. Galling, maybe due to uneven thermal expansion between Spindle and housing, etc
b. Leakage through gland packing. Common causes: packing extrusion due to too many PTFE (not 97% Graphite), too big clearance (more than 0.5 mm) between spindle and housing
Etc.

I would not feel confident shall my High temperature 400 degC Hydrogen gate valve only to be Hydrotested at ambient.
Company like Shell have define this in their own Type Approval Test, and some manufacturer Shell related have this testing capabilities as well. Of course there would be significant price adder shall you want perform such test against valve prototype

Regards,
MR


All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected