how to calculate the thickness for Vacuum condition as per ASME B 31.4
how to calculate the thickness for Vacuum condition as per ASME B 31.4
(OP)
Hi,
I have referred ASME B 31.4 edition 2012, where it is not clearly mentioned about the code or procedure to be followed for straight pipe under external condition .
whereas in ASME B 31.3, stated according to ASME sec VIII UG28.
my queries are.
1. how to verify the pipe thickness for full vacuum condition.
2. In table 403.3.1-1, allowable stress values are given for internal and external pressure, does it mean that code has take care the external load and full vacuum by stress values.
Regards,
Vinayak Nivendkar
I have referred ASME B 31.4 edition 2012, where it is not clearly mentioned about the code or procedure to be followed for straight pipe under external condition .
whereas in ASME B 31.3, stated according to ASME sec VIII UG28.
my queries are.
1. how to verify the pipe thickness for full vacuum condition.
2. In table 403.3.1-1, allowable stress values are given for internal and external pressure, does it mean that code has take care the external load and full vacuum by stress values.
Regards,
Vinayak Nivendkar





RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
http://mycommittees.api.org/standards/ecs/sc5/Tech...
It's up to you to make sure that the stress is <= allowable stress.
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
as per ASME B 31.4, allowable stress considered for thickness calculation are 0.72 x yield stress.
my basic doubt is whether vacuum thickness calculation applicable for ASME B 31.4, if yes then what will the ASME code to be followed.
ASME B 31.3 states ASME Sec VIII UG 28 to be followed for straight pipe under external pressure. like similar will follow in ASME B 31.4
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
B31.4 does not prescribe an exact method, so you may use any method that your experience dictates is appropriate.
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
I would look at either PD 8010-2 which provides some guidance or DNV OS F101.
You often need to decide what your worst out of roundness is before applying the collapse loads.
Unless you have large diameter, really thin pipe, they should normally withstand 1 bar differential from external pressure.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: how to calculate the thickness for Vacuum condition as per ASME B 31.4
At least Tips is usually a better alternative to asking some MBA-brandishing boss.