Maximum fillet weld leg size

[Paulettea]

Dear All,

I am working on a vessel as per SEC VIII Div.1 and I am having problem with a nozzle area calculations. The problem is that if I want to pass the area calculations per UG-37 I have to increase weld leg size. Here comes the question "what is the maximum weld leg size in a fillet weld?" for example if the nozzle neck thickness is 16mm and the shell is 26 mm can I use a weld leg size more than 16 mm?

Warm Regards

 

[SnTMan]

Paulettea, there is really no maximum fillet size as far as I know. You don't normally want to use a fillet that is very much larger than the thinnest member, but you can exceed that to make your calculations work.

I wouldn't cut it too fine though. Thicken up the neck?

Regards,

Mike

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

 

[DSB123]

The larger the welds the greater the chance of distortion

 

[DekDee]

I will quantify this statement by clearly stating I am not an engineer so not conversant with weld size calculations.
What I can say is my understanding is the CJP weld is your "sealing" weld and your fillet weld is your reinforcement.
Why would you need reinforcement thicker than the thinnest member ?

SnTman,
Interested to learn - how do you thicken the neck ? - use a thicker nozzle wall thickness ?
Regards,
Shane

 

[JStephen]

On the weld vs thickening the neck- mainly an economic issue, time versus material.
DekDee- the welds seal, reinforce, etc., but there is not a specific function applied to each weld in the ASME code. "Reinforcement" as used here refers to reinforcement of the nozzle, and is not the same as "weld reinforcement- weld metal in excess of the quantity required to fill a joint", as the AWS definition puts it.

 

[SnTMan]

DekDee, yes, thicker wall. As JStephen says reinforcement in this context refers to a specific calculation in pressure vessel work and refers to any metal that can compensate for the opening in the vessel wall, including excess shell and neck thickness, a pad and weld metal.

Regards,

Mike

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