Mr Kader,
A-860 fittings have to conform to requirements of A/SA-960 specification (Spec for Common requirements for Wrought Fittings). As per A/SA-960 clause 15.3.2 fittings may be ground to sound metal ,repaired and blended to the smooth. Some specific restrictions apply for fittings corresponding to MSS-SP-75.
In course of grinding, if the wall thickness is reduced below the nominal wall thickness , fittings may be rejected or repaired. However if the fittings are intended for sour-gas transmission or any other hydrocarbons, the repair has to be very selective and controlled.
If there is no choice but to use the damaged fittings, you may perform a Fitness for Service Evaluation, as per API-579 (Chapter-6). A Level-1, or 2 assessment may predict the safe service life of the components.
Thanks.
Pradip Goswami,P.Eng , IWE
Senior Engineer/Specialist(Welding-Metallurgy)
Engineering & Training Services Division
ONTARIO POWER GENERATION Inc.
PO Box-2000, RR-55(South)
Nanticoke, Ontario,N0A1L0
Tel:-(519) 587-2201, Ext 3107--in Nanticoke
(416) 231-4111, Ext 5925--in Kipling,Toronto
Fax: (519) 587-6814
From: pgoswami [mailto:pgoswami@quickclic.net]
Sent: Saturday, February 20, 2010 6:28 AM
To: GOSWAMI Pradip -THERMAL
Subject: FW: 4105] Pitting acceptance criteria
Pradip Goswami
88,Garth Trails Crescent
Hamilton, Ontario, L9B2X1,Canada
Tel-905-679-9677
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Gulam kader
Sent: Wednesday, January 20, 2010 4:52 AM
To: materials-welding@googlegroups.com
Subject: [MW:4105] Pitting acceptance criteria
Dear all,
We received one 40" elbow (ASME 16.9) ASTM A 860 material having so much pitting on full external surface. Which standard we can refer for the acceptance criteria?
I referred in ASTM A 860, its talks about only depth of surface discontinuity(5% of the nominal thickness), there is no detail about the area of the pitting allowance.
Please help me on this issue. Very urgent
Regards,
Gulam Kader
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