Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations IDS on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Proof Pressure. What is it anyway? 1

Status
Not open for further replies.
dacoach

dacoach

Mechanical
Mar 29, 2007
2
Is Proof Pressure a different test than a hydrostaic or pneumatic test for pressure vessel? What is it governed by with regards to testing requirements? 1.5 X MAWP or is it greater than that?

We bought an accumulator last year with the nameplate listing a MAWP of 3000psi and a proof pressure of 6000psi and a hydrostatic test rating of 4500 psi.

This year we are buying the same accumulator with a MAWP of 3000 but the proof pressure is said to be 4500 PSI (We haven't recieved it yet). Is their a std. with regards to proof pressure testing? Is it supposed to be 2X the MAWP? or can it be Lower or equal to say the hydrostatic test?


 
Replies continue below

Recommended for you

Sort by date Sort by votes
dacoach,

Refer to UG-99, UG-100, and UG-101 of ASME VIII Div. 1.

Is your vessel a hydraulic accumulator?
 
Upvote 0 Downvote
Yes it is a nitrogen over oil accumulator with floating piston. From what i am gathering from 1976-1989 proof test was synonomous with hydrostatic pressure test until ASME now defines it as a destructive test since it can cause deformation (i.e. burst test) so they don't want it used to refer to a hydro test.

Apparently hydro test to 1989 code year is 1.5 X MAWP and 1.3 X MAWP to 2004 code year but i guess you are also supposed to multiply some stress intensification factor ration to these to get your hydro test number..
 
Upvote 0 Downvote
dacoach,

That factor you are referring to is in UG-99(b). It is the lowest ratio of the stress value for the test temperature to the stress value for the design temperature.
 
Upvote 0 Downvote
In Italy gas cylinders (forged) in accordance with national safety requirement were hydrostatic tested at 1.5 MAWP and one sample each lot (max 200 pcs)was required to be burst tested and bursting could not occur at less than twice the MAWP. I presume other european standard required the same. Now, with the PED (Pressure Equipment Directive), things have changed. Probably your accumulators show those two pressures. According to ASME not the hydrostatic, nor burst test pressures shall be stamped: your uncertainity demonstrate ASME are right. Don't argue about other pressures stamped: trust on MAWP only. Mauro
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

YuJie_PV
  • Question
under what situation, the creep analysis is mandatory? 1
Replies
4
Views
2K
TGS4
TGS4
YuJie_PV
  • Locked
  • Question
is it allowed to avoid fatigue analysis by raising design pressure?
Replies
10
Views
260
XL83NL
XL83NL
V
  • Question
Is pressure retaining fillet weld qualification by fillet weld possible under ASME IX. 2
Replies
3
Views
2K
IdanPV
IdanPV
S
  • Question
Inquiry about pressure vessels
Replies
0
Views
152
Simon Aku
S
E
  • Question
Thin Walled Pressure Vessel
Replies
4
Views
1K
TGS4
TGS4

Part and Inventory Search

Sponsor

Back
Top Bottom