Reinforcing Pad Vent Hole Location
Reinforcing Pad Vent Hole Location
(OP)
Is there a standard location to orientate the vent hole on a reinforcing pad for ASME Section VIII, Div.1? ASME B31.3 says to put it on the horizontal centerline (not at the crotch). API-650 same thing. The Dennis Moss Handbook says at least 45 degrees from horizontal centerline. My shop says on the vertical centerline of the shell. Does it really matter?
Moss also indicates that an air test should be done on the reinforcing pad. My understanding is that this has never been the intent of ASME Section VIII, Div.1 and is not required.
Thank you,
Wes
Moss also indicates that an air test should be done on the reinforcing pad. My understanding is that this has never been the intent of ASME Section VIII, Div.1 and is not required.
Thank you,
Wes





RE: Reinforcing Pad Vent Hole Location
I also don't believe air test is required by Code either, but it is pretty much universally done. To me, it's money not worth saving...
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Reinforcing Pad Vent Hole Location
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
I don’t know the ASME codes as well as you guys should, so take this with a grain of salt. If there are no significant repad stress implications, I would put the vent hole as low as practical on the repad. I would like it to drain rather than take on and store water, if this can happen.
RE: Reinforcing Pad Vent Hole Location
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
What is the purpose of this test?
RE: Reinforcing Pad Vent Hole Location
See Process Industry Practices PIP VESV1002 Vessel Fabrication Specification
"Reinforcing pad attachment welds and accessible surfaces of inside nozzle to vessel wall welds shall be tested for the absence of leaks with a gauge pressure of 15 psig (100 kPa) dry air or nitrogen and bubble forming solution.
This test shall be prior to the final hydrostatic or pneumatic test as applicable"
Also this test is made when pad is over vessel weld seams.
Inspection is made from inside of vessel (if possible)
Also see ASME V for bubble solution test.
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
RE: Reinforcing Pad Vent Hole Location
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
As an exmaple, see the attached repad for a lifting lug.
Im not criticizing the application of vent hole, I strongly suggest them myself too, but whats the rationale on air testing that repad?
RE: Reinforcing Pad Vent Hole Location
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
Interpretation: VIII-1-13-10
Subject: UG-37(g), Split Reinforcement Pads (2010 Edition, 2011 Addenda)
Date Issued: April 25, 2013
File: 13-115
Question: Is the compressed-air and soapsuds test mandatory for split reinforcement pads?
Reply: No.
RE: Reinforcing Pad Vent Hole Location
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
What if there's 1 small crack in the (continuous) fillet weld? i dont see why the repad would fail then.
RE: Reinforcing Pad Vent Hole Location
Try to understand that defects are not allowable and shall be repaired, like cracks.
Please see in my sketch “WELD TO BE TESTED”: fillet weld around pad in nozzle is not the objective for examination. Air test is the objective to detect leaks in the weld between nozzle neck and shell.
Same concept to pad over a weld seam. Think about in service inspection too.
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
RE: Reinforcing Pad Vent Hole Location
Never I will sign a Manufacturer´s Data Report of Pressure Vessel if a crack is present.
Regards
r6155
RE: Reinforcing Pad Vent Hole Location
RE: Reinforcing Pad Vent Hole Location
Now then, as the vessel ages in service this pad may be monitored, by visual means (grease or sealer squeezing from the vent hole) or by actual pressure test for condition of vessel components beneath the pad.
If leakage at the pad were permitted at fabrication this would not be possible.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Reinforcing Pad Vent Hole Location