Fwd: Tension test requirement of Girth flanges as per UW-13 (f) for SA-266-2N
Raghuram Bathula
From: Janak Patel
[mailto:janak...@patelsairtemp.com]
Sent: Saturday, July 07, 2012 10:19 AM
To:
Cc
Subject: Advice requried for one Technical matter - Janak Patel
I
Dear Sir
Good Morning.
In one of the order for refinery equipments (H.E.), we had a technical issue on which I need your help / advice.
Question is related to Girth Flanges of Shell / Shell Cover / Channel.
1) Whether G.F. made of SA-266 requires Tension Test? Is it mandatory or supplementary?
2) If we have to do tension test (if applicable), then what is the location of the tension test piece?
3) Can G.F. be made by machining? Can we take ring forging (with OD x ID x total thk. including hub length) and then machine to get hub & other dimensions?
4) Is it allowed as per CODE? If yes, is it good engineering practice?
Small background on the matter :
Client has written in their document “Tension test required as per UW-13 (f) for SA-266-2N G.F.” I had replied that it is applicable for Tubesheets & Flat End Covers & not G.F.s. Then client had said that it is required as per “Section II Part A SA 266, Cl. No. 3.4 and SA 788, Cl. No. S12”. Also they had asked us to procure Ring forging and then machine it to make hub. They had also given sketch of it and shown tension test piece location (attached herewith for immediate reference). They had said that option b) in the sketch is preferred.
As per our understanding, Tension test is not required for SA-266 G.F.s. Also making a G.F. from a ring forging (by machining) is not a good engineering practice as it cuts the grain flow lines and makes it vulnerable to stress concentration / failures. I had also given literature on this to client (attached herewith for immediate reference).
Request to spare 5-10 minutes and give your valuable advice on the issue.
Many thanks in advance for your valuable advice.
Regards,
Janak Patel
Manager – Projects & Business Development
___________________________________________
PATELS AIRTEMP (INDIA) LIMITED
ASME “U”, “U2”, “R”, “S”, “NB” AUTHORIZED COMPANY
HTRI MEMBER (HEAT TRANSFER RESEARCH, INC. USA)
ISO 9001:2008 CERTIFIED
805,806,807 & 810, RAKANPUR - 382 721,
VIA : SOLA - BHADAJ VILLAGE,
TAL. : KALOL, DIST. : GANDHINAGAR,
GUJARAT, INDIA.
TEL : 91-02764-286634/35, 286480/81
FAX : 91-02764-286301
E-mail : janak...@patelsairtemp.com
Mob : +91-9904406059
Guru
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<SKMBT_C65012062814350.pdf>
<Forging Advantages from Scot Forge..pdf>
<what is grain flow.pdf>
Gurunathan R
Dear Patel;
Your Question with description of the flange:
You are going to purchase a SA 266 Gr.4 WNRF flange, which is designed as
per Appendix 2 of ASME Sec VIII Div.1, the query is does this forging needs to
meet the ordering requirement of SA266 Gr.4 specification which calls for,
hubbed flanges needs to be tensile tested as per SA 788 specification. Does
this requirement is mandatory even if it is supplied as forged WNRF flanges
Supporting Section II Part A Information for SA-266 and A-788 specifications:
SA-266 Grade 4 SPECIFICATION FOR CARBON STEEL FORGINGS FOR PRESSURE VESSEL COMPONENTS
3. Ordering Information and General Requirements
3.4 For hubbed flanges and tube sheets ordered for ASME Boiler and Pressure Vessel Code application, Supplementary Requirement S12 of Specification A 788 shall be specified in addition to Supplementary Requirement S8 of this specification.
S8. Specimen Location on Forged Hubs
S8.1 Forged hubs to be butt-welded to shells shall be:
forged in such a manner as to provide in the hub the full minimum tensile strength and elongation specified for the material, in a direction parallel to the axis of the vessel. A tension specimen (subsize if necessary) shall be taken in this direction and as close to the finished hub outside diameter as practical.
SA-788 SPECIFICATION FOR STEEL FORGINGS, GENERAL REQUIREMENTS
S12.1 For hubbed tube sheets and flanges to be used in ASME Boiler and Pressure Vessel Code construction, an axial tension specimen shall be taken as close as possible to the hub and either inboard or outboard of it, using a sub size specimen if necessary. The longitudinal axis of the specimen shall be parallel to the length of the hub, as shown in Fig. S 1.
S12.2 By agreement with the purchaser, this test orientation
may replace a specified tension test specimen, provided
that other location criteria are met.
Supporting information from Section VIII, Div. 1 Appendix 2:
Figure 2-4 Sketch 6 Illustrates a weld neck raised face (WNRF) flange.
The three sketches in Fig. 2-4 Sketches 6, 6a, and 6b locate the dimensions “h”, “g1” and“go” which are defined in 2-3 Notation as follows:
The term “h” denotes hub length,“go” denotes thickness of hub at small end and “g1”denotes thickness of hub at back of flange.
The final determination that this is a hub flange is the value of “”h” used in the flange calculations. Should any value of “h” be used which is larger than zero (0.0) the calculation will have taken credit for the hub.
The flanges shown in Fig. 2-4 Sketches 6, 6a, 6b and 7 are integral hub flanges and are calculated as such.
It is my opinion that your question may be answered as follows:
Reply: The flange described in your question is a hub flange as defined in ASME Section VIII, Div. 1 Appendix 2, designed using a value of “h” larger than zero.
Specification SA-266 calls in Specification A-788 and establishes the supplemental requirement S12 to be part of the specification requirements.
Based on this the tensile tests stated in S12 of A-788 are mandatory requirements for the described flange.