UW-21 External fillet size 1

[RBKN]

I have a nozzle with slip on flange and the required thickness as per design calculation is satisfied by a pipe with 1/2" Nominal wall thickness. We have a pipe with wall thickness of 1.031" in stock. If I decide to use this thicker wall pipe, do i still have to comply with UW-21 for the exterior Fillet weld?
design thickness: 0.353"
Required Tn: 0.5

but my Tn = 1.031".

Please advise.

 

[SnTMan]

Yes, you have to comply w/ UW_21, but see definition for Xmin. Note you are working with corroded thicknesses. Don't know the hub thickness? You can put a godawful drawing note such as "Lesser of (your calculated thickness, 1.4 tn) or hub small end thickness."

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[RBKN]

@SntMan

Yes, the Hub Thickness is 0.85" so i have to put 0.85" fillet as per UW-21.

I wont be using this thick a pipe if i have to make a 0.85" fillet. And I like to put minimum words on a drawing.

It's just that in the definition, t[n] is used and not design thickness. but generally if required thickness is 0.31" ( for instance) we can safely use a 3/8" wall ( no Corrosion Allowance ). And applying UW-21 will give a 0.525" fillet size. Now if someone uses 1" thick wall there instead of 3/8", and puts a 0.525" fillet, can we say it is in accordance with UW-21 ?

 

[SnTMan]

I's say no. The wording is what it is. Not that I agree with it, but still...




The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[RBKN]

Okay. Thanks @SnTMan