RE: [MW:3701] damage of packing material of SW valve after PWHT at site

Dear Vinayak,

 

The normal practice is to remove all packing material from valve, before pre heating, welding and PWHT operations. Once NDT of valves completed the same will be re fitted to the valves. The valve manufacturers additionally supply the packing material with valves. In case of critical lines, even the valve manufacturers are called for re packing, assembly operations. The leak tightness will be checked along with the line hydro.

 

 

Regards,

 

JIGNESH R RANA

---

From: Nivendkar Vinayak (Mumbai - Piping) [mailto:V.Nivendkar@ticb.com]
Sent: 20 November 2009 12:04
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

--
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.
Messages sent by email can be manipulated by third parties and are therefore generally not legally binding. This message contains confidential information that may be privileged or protected from disclosure. If you are not the intended recipient, please be advised that you have received this email by mistake. You are requested to notify us immediately by return email and delete this email from your system. Any use, copying, distribution or printing of information by the unintended recipient is strictly prohibited. Thank you.

Regd. Office: Uhde House, Vikhroli (West), Mumbai 400 083, India
Tel: 91-022-6796 8000, Fax: 91-022-2578 4327 Website: www.uhdeindia.com