About the test temperature for CTOD test in warm water.

[liuyuxi]

We know that CTOD test can be used to waive the PWHT. For offshore platform in high latitude, we normally use DNV requirement to determine the CTOD test temperature:For members above water should be the lowest air temperature, For members below water should be zero(freeze point of water).

This time we are working on a platform in a warm area(lowest air temperature 20 Celsius degree, lowest water temperature about 10 Celsius degree). If we still use the DNV rules, then a zero degree test have to be performed, but it is unreasonable(too low).
So which one should be used:15,10 or zero?
Any other codes have relative requirements?

 

[pipelinermike]

Per API 1104 (19th edition), Appendix A, the CTOD testing should be performed at or below the lowest anticipated service temperature (LAST). The 18th edition required testing at 15 deg C below LAST. You could also look to BS 7448 for guidance.

 

[grampi1]

0C should not be too hard to achieve with good welding practices.