Back bevel & re weld fittings

By qcrobert (***)

Date 08-10-2011 15:54

What code are you welding to?

By ruero

Date 08-10-2011 18:12

Oh ya 1104

By qcrobert (***)

Date 08-10-2011 18:44

ASME nor AWS Codes address the number of repairs allowed and I am not familiar enough of API 1104. I've heard 1104 allowed only two repairs in same location but that may be a contract specification and not a code requirement. Limitations on repairs would be based on service expectations and base metal.

Even though ASME doesn't specifically address the issue, Sec VIII Div1 part UHT-83 (UHT is for material Q&T steel) states Cautionary Note: "The properties of the base may be adversely affected by excessive local heat inputs". It deals with methods of metal removal such as machining, chipping, grinding, melting (gas cutting or arc-air gouging) of plate edges, welding bevels, chamfering, etc.. IMHO this would include multiple repairs (i.e., excessive local heat inputs.

Someone more familiar with API 1104 will answer your question with more integrity.

QCRobert

By 99205

Date 08-10-2011 21:56

API 1104, 10.2 (20th edition) handles that issue. It doesn't address how many times a repair can be made. Basically it says, the repair needs a procedure that has been "established and qualified". There's more to it, I'm just not typing the whole thing out.

By ruero

Date 08-11-2011 04:54

Sorry guys maybe did not make myself clear, this is not to make a repair it is to reuse the fitting. Starting with new fittings and then cutting pipe off because length needs to be changed. We fab up then of course the gas company changes what they want so we have to reuse the same fitting because it has already been hydro tested, like said i've seen it done up to 4 times on the same fitting. Gas company obviously does not think it is a problem and maybe not, just seems to me it would have some effect on the strength.

By 99205

Date 08-11-2011 07:10

I'm not sure, but because of the accidents lately, I think some Government Agency might have a problem with what you just described.

By qcrobert (***)

Date 08-11-2011 15:07 Edited 08-11-2011 15:12

>Sorry guys maybe did not make myself clear, this is not to make a repair it is to reuse the fitting.<

Ruero, I think we all understand that you are reusing a fitting that was previously welded on to a length of pipe. We are following the logic that "reusing" in this case would be considered a repair, especially since the codes do not address the reusing of fittings, per se. Unfortunately codes cannot not address all aspects of these activities but goes on to state that "those aspects which are not specifically addressed should not be prohibited. The code is not handbook and should not replace education, experience and the use engineering judgments". (taken from ASME foreword)

Bottom line is that the Client/Owner (gas company) is aware of this practice and does not limit the number of times of fitting reuse.

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>so we have to reuse the same fitting because it has already been hydro tested<

I don't understand that statement. Are you saying that after you reweld the fitting on that you do not need to perform hydrostatic testing again because it was tested previously?

Just trying to clear it up in this old brain,
QCRobert