Hydrotest Requirement per ASME B31.1

[Meck91]

Folks,

I need some information with respect to hydrotesting of piping per B31.3. Do we have any reference to below in code?
1) Test medium temperature,
2) Minimum equipment or pipe temperature,
3) Rate of pressure increase (??? PSIG/Min.)
4) Hold time,
5) Rate of pressure decrease (???? PSIG/Min.)
6) Is this standard practice, to isolate PSV's during hydrotest or depends on owner's specifications.

Would appreciate your help.

Regards,

Meck91

 

[davefitz]

For B31.1 see paragragh 137, or look in the index uner "pressure testing"

 

[JohnGP]

Or if you really meant B31.3 as referenced in the post, then refer to para 345 in that code, for all the requirements.
(Owner's specs will likely go into the detail that you are seeking though.)

Regarding isolation of PSVs during hydrotest - they are set at not more than design pressure (well at least one will be), so testing piping at 1.5 times design pressure means that any PSVs must be isolated in order to achieve that pressure.

Cheers,
John

 

[ak1965]

Please refer 345.4 in B31.3-2004


1) Test medium temperature,

The fluid shall be water unless there is the possibility of damage due to freezing or to adverse effects of water on the piping or the process. In that case another suitable non-toxic liquid may be used. if the liquis flammable,its flash point shall be at least 49 deg c, and consideration shall be given to test environment.


2) Minimum equipment or pipe temperature,

Refer as above

3) Rate of pressure increase (??? PSIG/Min.)

Not specfied in para 345.4 of B 31.3...however in 345.5 and 345.6 of B 31.3 for leak test , it specifies the pressure shall be gradually increased in steps until the operating pressure is reached.


4) Hold time,

Nothing specified in standar....however, we prefer 30 minute hold time.

5) Rate of pressure decrease (???? PSIG/Min.)

Not specified in B31.3...but should be reduced gradually

6) Is this standard practice, to isolate PSV's during hydrotest or depends on owner's specifications.

Yes, PSV must be gagged or removed and blinded.

 

[cjw81]

Hello gentlemen, would you please tell me what code is B31.3 referring to?

 

[JohnGP]

B31.3 is a code - full name is ASME B31.3 ASME Code for Pressure Piping

 

[Naif1981]

ASME b31.3
345.2.2
other test requirements
a)examination for leaks. A leak test shall be maintain for at least 10 min. and all joints and connections should be examined for leaks.

and this is a minimum time if you want to increase as ak1956 for 30 min it is ok
for me I preffer 1 hr min