Weldolet Thickness Consideration

[gkvengat]

Dear Friends,
I am having station piping work in pipeline.the piping system do not have PWHT.I am having 2 question inthis case

1.I qualifed the WPS with GTAW+SMAW upto the maximum thickness of 18.7 mm.My run pipe thickness is 15.09vmmm maximum.so i dont have any propblem in thickness range.Butin welding the Weldolets of size 20 X 2 SCH 40,18 X 2 SCH 40 & 24 X 4 SCH40 with run pipe,i am having the doubt,is my WPS will support or not?.During weldolet welding with Run pipe which thickness i will consider?

2.How can we measure the thicknes of a weldolet at the branch end (means,the mating part of weldlot with run pipe)?

Please answer me.In in trouble to justity this issue.

 

[pennpiper]

One of the problems when dealing with "O-Let" fittings is they do conform to MSS SP97 for the basics (and ASME B16.9 and B16.25 for Beveled Ends). However these Standards allow some flexibility to the manufacturers. These flexibilities include the body shape and wall thickness.

Theoretically you can do calculations based on a typical fitting but if you do not have the specific O-Let fitting in your hand and can insure that specific one will in fact will be used in the fabrication you are on a fools errand.

My recommendation: Locate an Authorized Inspector (AI) and discuss the issue with them and get an opinion.

prognosis: Lead or Lag

 

[gkvengat]

Dear pennpiper,
How can i calculate the thickness any formulae is available?

 

[pennpiper]

You don't need to "Calculate" it, Bonny Forge and WFI publish (see below) the basic dimensions. However they do not always follow their own numbers.

Dimension Chart;
Weld-O-Let -

http://www.wermac.org/fittings/dim_weldolet_sos.html

Sock-O-Let -

http://www.wermac.org/fittings/dim_sockolet.html

Thread-O-Let -

http://www.wermac.org/fittings/dim_thredolet.html

prognosis: Lead or Lag

 

[gkvengat]

Which dimension i will take.shall I consider B-C for thickness measurement in this chart.20 x 2 sch 40 is the dimension my weldolet means which NPS I have consider in the chart?20 or 2

 

[XL83NL]

There's a chart by, I think, bonney forge, showing weld thickness at the branch.
Furthermore, there's a useful article from an older ABSA newsletter, detailing for what thickness you need to be qualified.
Those two documents may help u further.

Ill post them 2morrow when Im back at work.

 

[pennpiper]

According to your original post your outlet sizes are 2" & 4" therefore use the 2" dimensions for the 2" branch and and the 4" dimensions for the 4" branch.

prognosis: Lead or Lag

 

[DekDee]

gkvengat,
This is from "Typical weld section profile of the Bonney Forge Weldolet"
2" Sch 40 Thickness - Longitudinal view (0.453" / 11.5 mm) Transverse view (0.312" / 7.9 mm)
4" Sch 40 Thickness - Longitudinal view (0.609" / 15.4 mm) Transverse view (0.375" / 9.5 mm)

IMHO you are fine to use a WPS with maximum WT of 18.7 mm.
Hope that helps,
Regards,
DD

 

[XL83NL]

gkvengat, try this link. Its from a previous post at eng-tips.com where I uploaded the weldprofile.pdf, which shows the wall thicknesses of olets.

Furthermore, check this and this (errata) link @ ABSA for details on qualifications on set-through and set-on (olets) connections.