k1_m_a,
This is a serious issue and you should be very careful with your decision. I will confirm Al's remark that PWHT is not something done to a selection of welds. If it is required it is done to ALL welds. I also understand the concern of the client. If Amine service causes failures that can be solved by PWHT then I would also want it done if I were them. I believe you are talking to the wrong people. A metallurgist (or materials science person) makes the decision on whether welds need post weld heat treated in a particular service, in this case Amine service. I think you will find that the people in this group are pipe designers who design the piping system. Pipe designers very seldom have the qualifications required to make the very important metallurgical decisions about materials of construction required for complex chemical service. I strongly advise you to look around for a metallurgist or materials expert in your organisation, or in an organisation you can trust, to help you with this one. I personally would not take advice on an important issue like this from people I do not know on the internet. Over the years I have learned that when it comes to serious issues it is important to take advice from people you absolutely know to be experts in the field you require advice in. I have seen many failures resulting from advice taken from people who are amateurs who think they understand an issue but in fact do not have a deep down understanding of the real issues at stake. Please seek the advise of a qualified and practising metallurgist or materials expert. If you do not have one in house, or you do not have access to an organisation that has one I suggest you contact companies that specialise in non destructive testing (NDT). They normally have qualified metallurgists on their staff. Also, be prepared to pay for the advice. This is important because if the advice given you is wrong you will have recourse to legal action. If you take advice from an amateur on the web and the advice turns out to be wrong, you will be left holding the candle.
"k1_m_a" <k1_m_a@yahoo.com>
17/02/2004 11:02 PM
Please respond to PipingDesign
To: PipingDesign@yahoogroups.com
cc:
Subject: [PipingDesign] PWHT for wled joints in Amine services
Hi,
Can anybody help me making a good decision regarding the necessity of PWHT for weld jionts in Amine services?
We are in construction part of a Gas Sweetening EPC project
containing three type of Amine services. A (Amine), AL ( Lean Amine)
and AR (Rich Amine).
Based on the criteria defined by the Amine plant designer engineer,
we have done PWHT only for weld jionts in AR ( Amine Rich) lines. But
now, we are under pressure by the Client that in any Amine service
including A, AL and AR all the weld jionts shall be Post Weld Heat
Treated.
Your kind answer based on your engineering practices, helping me to convince the Client that PWHT is not needed for A and AL services (or can be done only for some limited number of welds) is most appreciated.
I will be glad to give any more necessary information if needed, e.g. Gas composition, etc.
Thanking you,
Keivan Mashayekh
[Non-text portions of this message have been removed] Received on Tue Feb 17 17:53:00 2004
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