CREEP TEST TEMPERATURE AND STRESS

[Fizza453]

Dear Experts

How to decide test temperature and stress (i-e test matrix) for creep rupture stress test (also sometimes referred as accelerated creep testing). Material is SA-213-T22, operating temperature 500C, OD 31.8 mm, Thickness 4.0 mm. Boiler is in-service since 1983. Original Code of Construction is ASME Section I. Purpose of the creep testing is to determine creep life on the basis of actual testing data. Theoretically creep life assessment has already been performed as per API-579-1 Part 10.

Javed Nasir
Inspection Engineer
Technip-France Abu Dhabi

 

[DriveMeNuts]

Appendix H of API 530 might give you some tips.
I expect time would be the third consideration for the test.
Can you really get useful information from an accelerated creep rupture test of less than 20,000 hours?

 

[Dhurjati Sen]

Dear Fizza453,

Are you doing remnant life assessment for the boiler? Your procedure says to carry out creep test for the s/h tubes?

Regards.

DHURJATI SEN

https://www.nace.org/people/dhurjatisen

 

[Fizza453]

@DriveMeNuts: Thank you, I see Appendix H of API-530 and now searching the ASTM DS6S2 that is behind the Figure E.5 of API-530. I hope I can derive average stress rupture at test temperature and test duration (Test temperature and duration are embedded into LMP). Test less than 20000 hours generally not very useful information, testing on the basis of 1000 hours shows a greater scatter when compared with ASMT creep curves.

@Dhurjati Sen: yes we are doing remnant life assessment for the boiler. We have already conducted creep life assessment as per Part No 10 of API-579-1 and in addition to that client is also interested to see creep life assessment on the basis of actual creep testing.

Javed Nasir
Inspection Engineer
Technip-France Abu Dhabi