leak in welded joint

[raouf salhi]

Dear experts;

We have a skid of piping 10 " and 2 " API 5L welded and inspected according B 31.3.

we made already the internal hydro test (  two houres at 375 bar) in workshop and the result was satisfactory , we repeat the same hydrotest in the client workshop and we found a leak in one 2 " joints.

the RT report for this weld mention only undercut ( acceptable).

how we can explain this ?

regards

SALHI Raouf

QA/QC Engineer

[george....@gr.bureauveritas.com]

The detection of defects by RT is limited by a certain number of factors like:

Density
Penetration
Geometrical unsharpness
 
You have to thoroughly review your RTs for Code compliance
best regards

Dr. Georgios Dilintas

Authorized Nuclear Inspector
Authorized Inspector Supervisor

I&F REGIONAL TECHNICAL MANAGER
BUREAU VERITAS PIRAEUS - GREECE

Tel: +30 210 40 63 113 /4 /5
Fax: +30 210 40 63 118
Cell: +30 69 44 64 62 04


"'raouf salhi' via Materials & Welding" ---03/02/2015 05:10:16---Dear experts; We have a skid of piping 10 " and 2 " API 5L welded and inspected according B 31.3.

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[César Alexis Viteri Pérez]

Make a Failure Analisys, include macro and micrography of failed zone and fracture surface and all evidence available. Then try to find the failure mechanisms among all the tasks performed in the construction, transportation and test, in this order: test, transportation, construction/assemble/welding, materials.

Example: just imagine that the skid was lifted by the 2" pipe wich joint failed.

 Regards,
César Alexis Viteri Pérez

---

Date: Mon, 2 Feb 2015 13:50:25 +0000
From: material...@googlegroups.com
To: material...@googlegroups.com

Subject: [MW:22791] leak in welded joint

[Tadic, Miroslav]

Agree with Georgios.

 

As complement you could inspect your welded joint with advance ultrasonic testing (phased-array). This is a volumetric inspection method too, and with correct transductor and personnel, you  could have a good precision to evaluated and categorize the indication using acceptable and non-acceptable criteria from B31.3

 

regards

 

Miroslav Tadic
Integrity Enginner
CEE
Gerencia de Producción - Mantenimiento
YPFB Chaco S.A.

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/OF67436E33.0532C53D-ONC2257DE1.002CA9BF-C2257DE1.002CDBBE%40LocalDomain.

[Sergio Antonio Muñoz Pinzón]

Hello,

Defects can survive an hydrotest, then it can grow and appears as a leak, as César Vitero wrote some defects could grow during logistics or assembling.

Sergio Muñoz
IWE-IIW
http://Weld-ING.tk