[MW:4115] FW: 4105] Pitting acceptance criteria

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

Email-pradip.goswami@opg.com.

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

Email-pgoswami@sympatico.ca

Email-pgoswami@quickclic.net

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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