Impact Test Exemption
Impact Test Exemption
(OP)
Dear All,
I need a clarification from expertise in here regarding impact test exemption.
This is regarding UCS-66(b)(2), Code says that minimum design metal temperature colder than -48 degree C, impact testing is required for all material. My question is on the minimum design metal temperature (MDMT) above. Is MDMT above refers to system MDMT of the vessel or calculated MDMT after considered Fig. UCS 66 and Fig. UCS 66.1?
For example, based on client datasheet the MDMT is -50 degree C. I will go thru Fig. UCS 66 and Fig. 66.1 in order to get exemption on the impact test. Let say i get -60 degree C. The material right now is colder than client's MDMT, then no impact test require. However, based on UCS-66(b)(2), should i impact test this material?
I need a clarification from expertise in here regarding impact test exemption.
This is regarding UCS-66(b)(2), Code says that minimum design metal temperature colder than -48 degree C, impact testing is required for all material. My question is on the minimum design metal temperature (MDMT) above. Is MDMT above refers to system MDMT of the vessel or calculated MDMT after considered Fig. UCS 66 and Fig. UCS 66.1?
For example, based on client datasheet the MDMT is -50 degree C. I will go thru Fig. UCS 66 and Fig. 66.1 in order to get exemption on the impact test. Let say i get -60 degree C. The material right now is colder than client's MDMT, then no impact test require. However, based on UCS-66(b)(2), should i impact test this material?





RE: Impact Test Exemption
In my opinion, since the MDMT you are tyring to reach is -50C, unless you meet either of the conditions in UCS-66(b)(3), that is, ratio less than or equal to 0.35, or PWHT when not otherwise required (UCS-68(c)), you will have to impact test.
Regards,
Mike
RE: Impact Test Exemption
Thanks a lot for your reply.
If that is the case and by not considering conditions in UCS-66(b)(3) and UCS-68 (c), i still need to do impact test even though i can reduce (using Fig. UCS-66 and Fig. UCS-66.1) the MDMT below than -48 deg C?
RE: Impact Test Exemption
Regards,
Mike