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RE: [MW:32578] SA 516 GR 70- AVOIDANCE OF PWHT - 40 mm thickness

By Materials & Welding

Hi Vishwas,

Your query does not indicate the thickness , which is most critical aspect of choosing the PWHT cycle.

Irrespective of that, it's not advisable to leave one joint, especially the closing joint without PWHT and commission the vessel in service. You may better perform a LOCAL PWHT at the site.

Also using dissimilar consumable is encouraged , only if dissimilar metal welding is involved. In this case use of dissimilar welding consumable is not desired, that may add undue thermal stress in service on the joint welded.

 

Thanks.

 

Pradip Goswami.P.Eng, IWE.

Cell/Whasapp:1-905-9793232

 

From: james gerald <gerry_tup@yahoo.com>
Sent: October 29, 2021 6:46 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:32577] SA 516 GR 70- AVOIDANCE OF PWHT - 40 mm thickness

 

Please experts to share on Designer's view with respect to different lateral expansion though Design temperature is +250degC

 

Thanks & Regards

J.Gerald Jayakumar

 

 

 

On Friday, 29 October, 2021, 11:53:02 am GMT+4, Vishwas Keskar Welding Manager WELDING <vvkeskar123@gmail.com> wrote:

 

 

The vessel details are 

MOC - SA 516 GR 70 

DIAMETER- 4020mm

LENGTH - 37 MTR

MDMT = - 50 Deg C to  + 250 Deg C 

SERVICE - Non lethal /No Hydrogen Service 

 

We are proposing Vessel length build up as per FURNACE LENGTH CAPACITY(24 m maximum) and one joint WITHOUT PWHT  ( JOINING PWHTed sections earlier at site )

Proposal - 

1.MOC - SA 516 GR 70 

2.BUTTERING - ENiCrFe2 on 24 m section end and other at 13 m section end)

3,PWHT (section PWHT - One of 24  length and other 13 m)
 of  - 620 Deg C - 125 MINUTES 

4.Bevel preparation 

5.NDT - DPT 

Welding at site ( 24 m section with 13 m section) - ENiCrFe2 OR E309 

6.NDT - DPT AND UT

 

Expert opinion please  and share experience if any 

 

Vishwas 

 

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