Area Replacement Calc IAW Asme B31.3 - Help!

[Artois]

Hiya All,

I'm trying to work out the area replacement calculation IAW Asme B31.3, for a contoured body weldoflange, with a flat connection to a blank.

I have worked out the A1, A2 & A3 IAW Asme paras 304.3.3, but am stumped as to how to ascertain the A4 value.

I have got as far as the weld reinforcement area, but i cannot work out the barrel reinforcement, in the 'reinforcement zone'.

304.3.3 (d) states that reinforcement zone is "a parallelogram whose length extends a distance d2 on each side of the center line of the branch pipe and whose width starts at the inside surface of the run pipe (in its corroded condition), and extends beyond the outside surface of the run pipe a perpendicular distance L4"

Any clues?

 

[BigInch]

This isn't my spreadsheet and I don't remember where I got it, so "buyer" beware. Maybe it will help anyway.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[BigInch]

Try this link,

http://rapidshare.com/files/330712988/thickness_and_weld_branch_calc_to_ASME_B31_3.xls.html

Again, be sure to check it.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[ColonelSanders83]

The A4 value is the "area of other metal provided by welds and properly attached reinforcment" [para. 304.3.3(3)].

The picture on pg 23 [fig 304.3.4] shows shaded areas allowable for reinforcement. In your case the A4 value will be as shown in the file attached, a small rectangle that fits inside the reinforced portion of the weld. In your case this is not going to be a big number.

As to your other questions please study the figures and the nomenclature carefuly, the code is very discriptive here.

Just out of curiosity, why are you using a weld-o-flange? Would it not be cheaper to buy a weld-o-let and weld a standard weld neck flange to it? Weld-o-lets and weld neck flanges are reaily available, cheap, and require no calculations to use.

Just my two cents worth

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

 

[Artois]

Thanks guys! Fast replies cheers!

In response to Big inch - i don't think this covers contoured body connections, but thanks for the spreadsheet - useful all the same.

In response to your post Colonel Sanders - isnt that figure for an extruded outlet as opposed to a welded branch connection?

Using weldoflanges due to them requiring less weld than the more conventional method (a high number of units having vent connections) & thusly less NDT, time was of the essence to get these units out the door, so to speak. I'm told the flanges are self reinforcing (with type approval to justify), but i want to prove that it myself and iof the third party question it. So far it is massively over compensated, but i just want to finish the calc off accurately.
Your two cents is greatly appreciated

 

[ColonelSanders83]

Artois,

There is no figure for your particular application. You might notice there is no figure for a weld-o-let either. However, the reinforcement for the backup weld on a weld-o-let is closer to the taper on an extruded branch than it is to a fillet weld for a repad (with equal leg lengths) If the fitting is already grossly overcompensated, simply state in the calc that any additional reinforcement (A4) was neglected as a conservative assumption due to the uncertain nature of its calculation. It is not cost effective for you to waste your time in gaining an extra 5% of area reinforcement if you already have 150% plus.

You could also simply request proof test from the manufacturer. See para. 304.7.2 Which directs you to 304.7.2. Section (C) is all you need. Chances are the vendor meets at least one of the proof test requirements.


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

 

[eliebl]

If you have access to the MSS-SP standard that covers olet type fittings it calls for the manufacturer to have proof tested them. If memory serves the standard is MSS-SP97.

EJL

 

[ColonelSanders83]

eliebl,

MSS SP-97 Integrally Reinforced Forged Branch Outlet Fittings covers Socket Welding, Threaded and Buttwelding Ends fittings, not Flange Outlet Fittings.

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

 

[LSThill]

BigInch (Petroleum) your file is not current with the 2008 code

RE: missing: W = weld joint strength reduction factor per para. 302.3.5(e)

ASME B31.3 2008 304.1.2 Straight Pipe Under Internal Pressure (equation 3a & 3b) page 20.
W= wld joint strength reductio factor per para. 302.3.5(e) Page 19.

http://rapidshare.com/files/330712988/thickness_and_weld_branch_calc_to_ASME_B31_3.xls.html

L S THILL

 

[Artois]

Thanks all - Appreciate your time in helping me out.
Got it sussed now