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RE: Field welding

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Dave,

 

Are you in a position to propose to the engineer the way it should be done with appropriate reasons and references?  If he also has reasons and appropriate references, it shouldn’t be too difficult to look at them together, sort them all out and come to agreement.  This is part of the open lines of communication between designer and builder that every project should have.  I expect that you would then be able to quickly come to agreement on the procedure that will be used.

 

Nels Roselund, SE

South San Gabriel, CA

njineer(--nospam--at)att.net


From: dave lowen [mailto:jatech(--nospam--at)kwic.com]
Sent: Thursday, September 08, 2005 2:26 PM
To: seaint(--nospam--at)seaint.org
Subject: Field welding

 

This is a note on the contract drawings I am quoting from;

 

“Field welding to existing structural steel.

Prepare serfaces (sic) of existing steel for welding by removing all paint and grinding clean to white metal.

Preheat to a minimum of 200 degrees F. in order to control the cooling rate.

Permissible welding stresses shall be taken as only 50% of normal allowable stresses when welds are performed in shop.”

 

For starters, the cooling rate is controlled by postheat, not preheat.

Secondly, I am assuming when the EOR says “allowable stresses”, s(he) means allowable weld  values.

 

My questions are; can an engineer mandate pre or post heat for welds that only require the material to be at ambient temperature according to AWS?

And, can an engineer mandate a factored allowable weld value when the code allows full values for field welds.

 

 

 

Regards,

Dave Lowen

Jarvis

V 519 587 5797

F 519 587 5138

E jatech(--nospam--at)kwic.com

 

Waterloo

V 519 749 9468

E jatech(--nospam--at)bellnet.ca