Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
(OP)
Lifting lugs designed for -45 °C MDMT vs meet impact req 20ft-lbs at
As a new guy in this industry, I just want to know what's the difference of these two statements. Which is right? Our QC staff ask me to change the 1st one to 2nd statement in the datasheet... But I always use the 1st one before...
Thanks.
As a new guy in this industry, I just want to know what's the difference of these two statements. Which is right? Our QC staff ask me to change the 1st one to 2nd statement in the datasheet... But I always use the 1st one before...
Thanks.
3 years industry experience;
Oil & Gas industry in Canada.





RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
I have seen this -45C requirement on some Owner specs. I usually ask why, but I can't get a reasonable answer. The usual answer is "it's in the specs for years" or "lifts will be done during winter". For sure there's a good reason. But until I hear one, I think the -45C requirement on lifting lugs is just a waste of money.
Let's say the ambient temperature is -45C. With winds at 15 kph, the wind chill factor could be -60C. Would rigging folks be willing to perform lifts on a brutally cold day? And surely the cold weather will affect the performance of the lifting equipment or crane (re: shock loading, hydraulics). Doing lifts on a -45°C day is just insane.
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
In Canada, I think -45C is routine requirement for outdoor equipment.
Duwe6:
What I think is that 20ft-lbs at -45°C is a fixed requirement. But the ft-lbs at -45C should be changed per material. Some are 15 ft-lbs. Thus, I think just mention -45 °C MDMT is a reasonable clause and the vendor need to verify the detail. Not sure if this is correct.
3 years industry experience;
Oil & Gas industry in Canada.
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
Where in Canada?
In Alberta, we don't routinely design vessels for -45°C MDMT. Most of them are designed for -29°C MDMT. But we do require that supports such as skirts be designed for -45°C.
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
- Insulated or indoor components : -29°C (please confirm it to your client)
- Uninsulated components : -45°C
Most lifting lugs, skirt, saddles, supports, and steel structures are operating under uninsulated condition.
Even though ASME BPV codes do not cover the non-pressure boundary components, most end-users are using the requirements (including mitigation and exemption) of impact test for pressure parts in ASME BPV for them.
In your case, the impact test evaluation (requirements, mitigation and exemption) per the ASME code for the vessel should be considered for the welds [-29°C (when confirmed) for insulated and -45°C for uninsulated] as well as the base metal.
Thomas Eun
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
You are correct.
I also checked with some senior engineers in house.
They told me the general rule in Alberta is
- Insulated or indoor components : -29°C
- Uninsulated components : -45°C
Both of them may be changed per process condition. Normally the client will specify their requirement.
The 20ft-lbs impact test requirement for lifting lug is a general rule we used before, even it is not in any standards or codes as you mentioned it is not within the scope of ASME SEC VIII.
3 years industry experience;
Oil & Gas industry in Canada.
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
"designed for -45 °C MDMT" = meets required MDMT but possibly exempted from impact test by some means
"meet impact req 20ft-lbs at" = base metal and perhaps weld procedures etc actually tested at the temp of interest
Depending on what's actually wanted, could be a world of difference:)
Regards
Mike
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
Yes, thanks. It makes sense.
The interesting thing is that, I cannot find any clauses, neither in codes nor our client's standards, to request the 20ft-lb test.
If that is a extra requirement, it should be in a standard or specification whatever from our client or ourselves..., Right?
I also asked someone else in our company, but did not get any clue yet.
3 years industry experience;
Oil & Gas industry in Canada.
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
If it is indeed a requirement, it must be written down somewhere, right? Make whoever is requesting produce it:)
Regards
Mike
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
Regards
rhg
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
regards
rhg
RE: Lugs designed for -45 ¦C MDMT vs meet impact req 20ft-lbs at -45¦C
Besides, test labs are notoriously inaccurate with grain size assessment.