weldolets 2

[sftyvlv]

Can someone tell me where in the B31.1 code weldolets must be used and why. To me "olets" in many cases seem to be overkill especially when a 3M forged coupling with a full penetration and fillet weld would do the job, unless the pipe wall thickness is excessive.
Sftyvlv

 

[doct9960]

Nowhere.

The use of an "olet" is an option, not a mandatory code requirement.

 

[GregLamberson]

DOCT9960 is correct. One company's rule of thumb I worked with was they should not exceed 2 inches with a maximum branch size of one nominal pipe size smaller than the run.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[deanc]

http://www.bonneyforge.com/

I would say it depends what you want to do. Do you have a 2500# item with a 2" wall? I would rather use a "olet" the trying to insert a coupling.

There is no requirement for weld fill to the outer edge of the fitting only min. size.

Cost and time vs item. The Code is flexible.

 

[davefitz]

I seem to recall that extra reinforcement must be provided if the branch is greater than 70% of the main run.

 

[davefitz]

see B31.1 par 127.4.8 . Regardless of diameter ratio, adequate reinforcement must be proven.

 

[MJCronin]

Davefitz, as always, is correct...

Sftyvlv, the ASME code mandated pressure reinforcement at piping joints is not a matter of "whatdya think" judgement...

It is well defined in ASME B31.1 and B31.3. Tees, elbows weldolets and other components are "pre-qualified" for the piping wall thickness to which they must be attached.

Pressure reinforcement of connections is discussed in the "Piping Handbook" by Nayyar.

My opinion only..

MJC

 

[DSB123]

deanc,
Can you elloborate on your statement

"There is no requirement for weld fill to the outer edge of the fitting only min. size."

I am intrigued as to what you are meaning.

 

[LSThill]

Tean Members:

Regards to deanc (Specifier/Regul)

Reference Libary has the

http://www.bonneyforge.com

technical paper showing the detail calculations for weldolets.

you may woan to contact

http://www.bonneyforge.com

by email and request technical papers.

 

[deanc]

DSB123

Isthill has pointed you to the web site and they do have info. on this. davefitz also has some insight.

However, I will attempt to explain. I have seen many manufactuers and welders take the attachment weld to the OD of the fitting. They fill the entire bevel with filler.

This is not needed. If you meet the Code requirements for min. weld size and reinforcement you are finished.

This may be your open groove root and a fillet or two. You may be using this as a "stick on" so those rules would apply. Keep your eyes open for next Code issue....UW-16(f) is changing and speak with your AIA.

 

[jte]

Take a look at

http://www.bonneyforge.com/OletCat.PDF

and go to page 35 (catalog page number, or page 34 of the pdf) which is titled Installation Procedure. The top middle picture provides the definitions of weld line and rib. What deanc is saying, and I've seen it too, is that often the welders think they have to weld all the way up to the rib. The weld required by the manufacturer of the fitting is only to the weld line. This is what has been qualified by testing. Any additional weld doesn't add value.

jt

 

[LSThill]

jte (Mechanical) & deanc (Specifier/Regul)

I did not mean reference to catalog page number information but the detail technical paper showing the detail calculations for weldolets.

Ask for bonney forge technical papers showing the detail calculations for weldolets.



L S THILL

 

[DSB123]

jte,
What you say is what I beleive to be the requirement i.e. The attachment weld should be to the weld line on the weldolet. From reading deanc's original post I assumed he was stating that the weld does not need to be filled out to the weld line of the o'let which is not the case. All o'lets should be welded such that the weld is large enough to reach the weld line on the weldolet.

deanc,
If I have mis-interpretted your original post then appologies but in your second post you say " If you meet the Code requirements for min. weld size and reinforcement you are finished.

This may be your open groove root and a fillet or two."

I think this is not the case and the weldolet should be fully welded out to the weld line in order to use the SIF's from the Code or manufacturer (in the case of Bonney Forge).

If you just weld an open groove root plus a fillet or two then you cannot use the Code SIF's.

 

[jte]

LSThill-

Thanks, but I'm not looking for calc's - the point is that in many cases weldolets are mis-installed (unnecesserely large weld). So the Installation Procedure is enough to explain to folks how much weld needs to be laid down. Ever tried to get a welder to go through and understand a calc?

jt

 

[sftyvlv]

jte
As a matter of fact in Canada, specifically Ontario our welders are finding out welding is not a "stupid" mans trade. In Ontario welding is a trade and believe it or not some can read a PQR and WPS.
Our QC at the power plant has our welders flush the olet out then weld the proper fillet. As per code if the legs of the fillet exceed 3/4" manditory PWHT is called for. Many welders weld a fillet to the transition point of the olet and thus overwelding and repair is neccesary to avoid PWHT.
sftyvlv

 

[jte]

sftyvlv-

No intent to offend welders! I've dealt with too many good ones to do so. But I don't expect to be a good welder, and I don't expect a welder to be a good engineer. We specialize for a reason.

I don't quite follow when you state that "... overwelding and repair is necessary..." Just not visualizing what you're describing- can you restate what you said?

jt

 

[LSThill]

jte (Mechanical)

Instade of the World Calculation; I should have said Bonney Forge Technical Bulletin or Tehcnical Paper's which is the technical reference you may be looking for.

 

[deanc]

jte is pointing to the easy path. Should be acceptable.

sftyvlv,I poke at welders too. That is where I started,well lets just say,a couple of years ago. Most are good folks...but welders are welders. Kinda like engineers and AIs.

I have emailed bonneyforge and asked them to post the calcs. or a direct link here.

Thanks jte and Isthill.

 

[sftyvlv]

jte
There should have been a period after "overwelding" and a new sentence started with "Repair from overwelding would be neccesary to avoid PWHT".
sftyvlv