[MW:25811] RE: 25809] Temporary piping used in hydrotest - ASME B31.1

Hi,

As per general practice,  temporary piping NDT & PWHT is not Mandatory – however for taking the decision so many if's and But's are their…

 

In one of my inspection days, piping material is of higher strength and with joint efficiency of 100% (due to 100% RT), but temporary piping is acquired by our local contractor and we also not monitored properly – neglecting that it is a temporary piping…

 

In the same HT, 6 failures are happen …

 

Failure 1.  - @25% HT Pressure – temp piping joints started leaking (welder used 7018 without baking and with lot of negligence – lot of porosity evident)

Failure 2. – @30 % HT Pressure – one more joint – identified defect is Lack of penetration and joint opened (can assume it's a becomes a simple butt weld)

Failure 3 -  @40% HT pressure – tapping made for the instruments – fillet welding leak – SS nipple  to MS piping – no proper consumable used.

Failure 4 - @50% HT pressure  - Used asbestos gaskets given problem – changed to Neoprene rubber / EPDM

Failure 5 - @75% HT Pressure – few more joints started leaking – all are weld defects

Failure 6 - @ 85% HT Pressure – my seniors warned that the used MS piping can be busted at any time due to low "YS" and recalled the entire activity

 

Finally one more senior joined with me and guided me and trained me for the total issue – later on we had replaced the entire piping and with the proper WPS and all NDE measures implemented and successfully completed the test in one go….

So don't take risk and each failure will cost u to repeat the entire test…

 

Final decision is with the client and contractor only – because NDE will incur some cost and time..

 

Also thickness of dummy – u can take reference of any code – as per ASME, IS or BS – anything is acceptable

 

 

Thanks & Regards,

Lakshman Kumar B,

+91 9440031459.

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Zakaria ghrab
Sent: Saturday, December 10, 2016 8:11 AM
To: materials-welding@googlegroups.com
Subject: [MW:25809] Temporary piping used in hydrotest - ASME B31.1

 

Dear Experts,

 

  Could you advise us: For piping system hydrotests power plant project, we ave to prepare and use some temporary piping. The issue is :

 

- Is it Manadatory to perform NDE in related welds  and also PWhT

- For Flange fabrication, how to use plate thickness, any code or standard reference !

 

Please advise according your experience and with ASME reference .

 

Thank you.

 

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Thanks and Regards, ?

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زكرياء غراب
GHRAB Zakaria 

Tunisia : +216 96 635 805

Yesterday is the past, tomorrow is the future; and today? Today is the present, the gift: Enjoy it!

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