Branched reinforcment calculation when using a weldolet

[fizzy]

Hi,

Can someone please tell me how to calculate a branched reinforcement when using a weldolet to connect the header to the branch. Secondly how can i determine the thickness of the weldolet to be used in my calculation.

Many Thanks in advance

Fizzy

 

[DSB123]

When using a weldolet you do not need to perform branch reinforcement check calculations. The reason why you use a Weldolet is that it automatically provides sufficient reinforcement (provided the correct schedule is chosen for your application)and hence calcs are not required. The only thing you need to watch is that the Weldolet is "fully welded out" during construction. If it is not then the Code SIF's cannot be used in Stress analysis.

 

[fizzy]

Many thanks, DSB123.

I've got a 20" sch 60 header and a 4" sch 80 branch connection; from ur explanation, i take it that a 20"x4"WOL sch 80 will do. Is the header pipe the basis for the weldolet selection?

 

[StevenHPerry]

Bonney requests that both the header and the branch schedule be specified. Bonney Forge's print catalog is pretty good with the explanations on how to order and then how to install, but their website seems to be lacking details.

"Weldolet, 20NPS S-60 x 4NPS S-80, ASTM A???, MSS SP-97" is an example spec, from memory. The MSS number may be off.

I bet it's the same everywhere, though substitute their brand name for "Weldolet."

- Steve Perry

http://www.linkedin.com/in/stevenhperry

This post is designed to provide accurate and authoritative information in regard to the subject matter covered. It is offered with the understanding that the author is not engaged in rendering engineering or other professional service. If you need help, get help, and PAY FOR IT.

 

[ColonelSanders83]

Depending on which code you are using there will be line exempting you from being required to perfrm a branch reinforcment calculation on a Integrallt reinforced branch connections in accordance with MSS SP-97.

The reason behind this is that Inegrally reinforced branch outlet fittings have thier design verified through destructive testing. This requires that the pipe fails before the branch and therfore reinforcing areas are not a concern.

For stress at the branch the appropriate figgur in the SIF table in your applicable code should be used.

Just my two cents worth.

A question properly stated is a problem half solved.

Always remember, free advice is worth exactly what you pay for it!

http://www.ap-dynamics.ab.ca/

 

[MJCronin]

Fuzzy...

Do you have a piping line specification for your project ? This document would define branch connection requirements for various line classes.

What is the design pressure, temperature and material of the header pipe ?

Is this work being done to ASME B31.3 ? If so, please consult the chapter and verse of this code for a more complete explantion of weldolet acceptability.

 

[fizzy]

Thanks guys for your replies,

MJCronin, the design code is B31.4, the design pressure:172.4barg, design temp: 57.4C/-41C, the header and branch material is API 5L X60.

I know weldolets are acceptable but wanted to confirm standard thicknesses and possibly if branch replacement calculations are needed. I'm not a piping lad and dont come along weldolets often.

Cheers.

 

[Duwe6]

fizzy, MJCronin is talking "Line Spec" and you are talking 'pipe spec'. A Line Spec is a 'cookbook' of the acceptable pipe materials, sizes, connections, type & rating of valves and flanges, etc. for a particular range of process fluids at a specific range of temperature & pressure. All the engineering calc's have been done on each size/schedule/spec & grade of pipe, and the allowed branch connections on that particular type of pipe have also been precalculated.

Without a Line Spec, you have to do a full set of calc's for all possible combinations, permutations, and corrosion rates *every* time you install a pipe circuit. Try to find a copy of a good, developed set of Line Spec's that will cover carbon steel. 304 and 316 stainless steel, both 150# and 300# flanges That's 6ea. individual Line Spec's, just for a basic set.