Fabrication of CRA overlay welded pipeline for Sour services 2

[Mateeng]

Hi Fellows,
I have two questions regarding the CS pipeline overly with alloy 825 for sour services:
1.Do we need to use CS NACE comply material (HIC and SCC tested) for base material?
2. After alloy 825 weld overlay does the pipe need to be PWHT?
I did look on the NACE MR0175/ISO 15156 para A.2.1.5 and did not get a clear answer to my questions.
Any comment and clarification refering to NACE and experiances in the past appreciated.

 

[SJones]

1. Refer to ISO 15156-3, A.13.1, paragraph 2
2. Refer to ISO 15156-3, A.13.1, paragraph 2

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[stanweld]

Enjoy the hot cracks when weld overlaying 825 over carbon steel.

 

[Mateeng]

Hi Steve,
Thanks for your post. Actually I was looking to have your interpretation regarding the necessity of NACE comply material where we are using weld overlay in sour services and moreover if stress relief is required for CS overly with alloy 625 for sour services.
NACE MR0175/ISO 1516 part 3 clause A.13.1, paragraph 2 is not clear enough.
Can you provide your interpretation for captioned para more in detail.

Stanweld
We are going to use alloy 625 for weld overlay and not alloy 825. Good point.

Thanks

 

[SJones]

ISO 15156 is not a complete menu of decisions, much as most people would like, and a great deal is left to the 'end user' to make the call on. Thus, I cannot provide an interpretation because I am not the end user and I do not have the complete array of information necessary to judge the risk and make the call. All I would proffer is: having deposited a CRA, think long and hard about potentially damaging it with a heat treatment; on the other hand, achieving compliance for the carbon steel could be the difference between a leak and a rupture should the CRA be breached. Good luck with your deliberations.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[stanweld]

We have had two Customer's order Alloy 625 weld overlayed, line pipe for similar applications. We did the field welding construction. Neither required PWHT or HIC/SCC testing of the base material.

 

[Mateeng]

Stanweld and Sjones,
Thanks for your comments.

 

[OGMetEngr]

Stanweld, if you only did joining of the pipe it may have been buttered, thus requiring no pwht. Completely depends on what strength and alloy is being clad if pwht is required or not.

 

[stanweld]

OGMetEngr,
Per the contract specifications, we field welded with E/ERNiCrMo-3 (I would have up-alloyed for the service). PWHT was not required by B31.3, the applicable Code. Base pipe material was seamless carbon steel. I did review the O.L. WPS of the fabricator and did have the contract specs for the pipe.

 

[pradipgoswami]

Hi Mateeng,

You need to look through clause 5.4,of API-5LD, 2009 for Heat Treatment. PWHT following CRA weld overlay could be asked by the client subject to base materials being used and design requirements . C.S pipes may be exempted from PWHT following weld overlay subject to project requirements.All testing (both mechanical and chemical) requirements are clearly specified in API-5LD and should be met.

Thanks

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299