Skip to main content

[MW:3696] RE: 3694] damage of packing material of SW valve after PWHT at site

By Materials & Welding
hi Vinayak,
 
You are very much right regarding damage to the valve packing .
These SW valve shall be procured with 100 or 150 mm Puff ( a piece of pipe ) welded on both side by.
 
PWHT at valve end shall be done by manufacturer.
 
hope it clarifies.
 

Kind regards

Rahul


From: Nivendkar Vinayak (Mumbai - Piping) [mailto:V.Nivendkar@ticb.com]
Sent: vrijdag 20 november 2009 7:34
To: piping_valves@yahoogroups.com; materials-welding@googlegroups.com
Subject: [MW:3694] damage of packing material of SW valve after PWHT at site

Dear all,
 
In the piping class of alloy steel, we have SW end small bore gate, globe valves. And as per the client requirements all Alloy steel piping joints shall be PWHT after welding.
 
Now , if we performed the PWHT at site at temp. 704-760 Deg C (As per ASME B 31.3 Table 331.1.1 Requirements for heat treatments), then is there any possibility of damage to packing material which is normally graphite due to heat dissipate during PWHT.
 
What type special consideration to be taken in this case. Members are requested to give suggustions.
 
Thanks in advance..
 
Regards,
Vinayak


____________________________________________________________________________
This email has been scanned for Viruses and Spam. For more information
please contact your local Business Unit Information Security representative.
____________________________________________________________________________

--
To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

Comments

Post a Comment

Popular posts from this blog

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

By Materials & Welding
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
Post a Comment
Read more

[MW:5202] RE: 5200] NDT after PWHT

By Materials & Welding
------------------------------------- Interpretation:  I‑89‑14 Subject:         Section I (1986 Edition, 1987 Addenda), PW‑11,                  NDE Prior to PWHT Date Issued:     December 15, 1988 File:            BC88‑393   Question: Does PW‑11 require that NDE be performed on welds after they have been subjected to the postweld heat treatment required by PW‑39?   Reply: No, unless the conditions described in PW‑11.2.2 exist. ---------------------------------------------- Interpretation:  VIII-1-98-09 Subject:         Section VIII, Division 1 (1995 Edition, 1996 Addenda); NDE                 ...
Post a Comment
Read more

Materails FAQs

By Materials & Welding
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...
21 comments
Read more