API 610 (Hydrotest pressure concerns)
API 610 (Hydrotest pressure concerns)
(OP)
Hi,
I am currently working on OH2 type pump that is in compliance with API 610 11th Edition.
Connection sizes are as follows : Suction : 6" /300lb/RF
Discharge : 4" /300lb/RF
Material of construction selected for this application is A351 CF8M.
I have a concern in terms of hydrotest pressure.
Now,with reference to API 610 11th Edn,6.3.5b)MAWP is equivalent to 40barg at 38 degC.In this regard,Hydrotest pressure should be equal to 1.5 times MAWP,that is 60 barg at 38 degC.
But when i referred to ASME B16.5 for flange fittings,in table 2.2.2,maximum working pressure for flange rating of 300 lb at 38 deg C is 49.6 bar
Having outlined that above,my question is
- Is it feasible to perform hydrotest at a pressure ( 60 barg ) in excess of max working pressure (49.6 barg) of flange fittings at the said temperature ?
Thanks for your reply in advance.
I am currently working on OH2 type pump that is in compliance with API 610 11th Edition.
Connection sizes are as follows : Suction : 6" /300lb/RF
Discharge : 4" /300lb/RF
Material of construction selected for this application is A351 CF8M.
I have a concern in terms of hydrotest pressure.
Now,with reference to API 610 11th Edn,6.3.5b)MAWP is equivalent to 40barg at 38 degC.In this regard,Hydrotest pressure should be equal to 1.5 times MAWP,that is 60 barg at 38 degC.
But when i referred to ASME B16.5 for flange fittings,in table 2.2.2,maximum working pressure for flange rating of 300 lb at 38 deg C is 49.6 bar
Having outlined that above,my question is
- Is it feasible to perform hydrotest at a pressure ( 60 barg ) in excess of max working pressure (49.6 barg) of flange fittings at the said temperature ?
Thanks for your reply in advance.





RE: API 610 (Hydrotest pressure concerns)
Just for your future reference, referring to "ASME B16.5 Class 300" flanges as "300 lb" has led to no end of confusion on this site and in the world. Calling it ANSI 300 class, while obsolete, causes less confusion. When you say "300 lb" most people flip that in their mind to "300 psi" which it certainly isn't. I've been doing this stuff for over 30 years and I kind of stumbled over the "300 lb" in your post even though I've been warning people about it for years.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. —Galileo Galilei, Italian Physicist
RE: API 610 (Hydrotest pressure concerns)
Johnny Pellin
RE: API 610 (Hydrotest pressure concerns)
Johnny Pellin