Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
(OP)
I've noticed that pressure vessels built in the 1940s and 1950s were often shop-hydrotested at pressures much higher than 1.5X (now 1.3X) required by the Code and was curious to understand why. Some vessels that were carbon steel construction with design temperatures below 650 F (temperature correction factor = 1.0) were hydrotested at more than 2X the listed MAWP. This applies to ASME Section VIII (there were no Divisions I/II/III yet) as well as API-ASME pressure vessels.
Were the higher hydrotest pressures due to special Code requirements in place at the time or was it just a common industry practice during that period?
Thanks.
-Christine
Were the higher hydrotest pressures due to special Code requirements in place at the time or was it just a common industry practice during that period?
Thanks.
-Christine





RE: Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
Cheers,
gr2vessels
RE: Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
I'm not sure if that is relevant to you or not.
RE: Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
RE: Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?
The higher hydrotest pressures were due to the Code requirements in place at that time. Some of the vessels in the 1940's were hydrostatically tested to at least twice the MAWP. Check out Paragraph U-77 on page 77 of the ASME Section VIII 1943 Edition...
https://law.resource.org/pub/us/cfr/ibr/002/asme.u...
RE: Reason for Unusually High Hydrotest Pressure on Older Pressure Vessel?