Non-Pressure Fillet Welds vs Pressure Fillet Welds 1

[jayinwww]

Non-Pressure Fillet Welds vs Pressure Fillet Welds.

When welding a shoe attachment directly to a pipe that contains pressure. Is this considered a Pressure Fillet Weld or a Non-Pressure Fillet Weld?

Or is it considered a Pressure Fillet Attachment? Another argument is that a Socket Weld is a Pressure Containing Weld.

Any thoughts or clarification out there on this>

 

[Cobra17]

Don't think of it as a pressure fillet weld or non-pressure fillet weld, think of it as a pressure retaining weld. A socket weld contains the pressure because if the weld isn't there, the pressure would be open to atmosphere.

 

[SnTMan]

Might also be useful to think of welds as on the pressure boundary, or not on it. Welds on the boundary may or may not be pressure retaining, welds off it will not be.

Regards,

Mike

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

 

[r6155]

Fillet welding must be done by a qualified welder, and it does not matter if it is a pressure component or a structure.

See AWS A3.0M 2020 Standard Welding Terms and Definitions
Fillet weld.. A weld of approximatelly triangular cross section joining two edges in a corner joint, one surface and one edge in a lap joint, or two surfaces in a T-joint.

Regards

 

[jayinwww]

Thanks SnTMan! We are going to go with Pressure Boundary, or perhaps External Pressure Boundary.

 

[KevinNZ]

Think about like this. If the welded cocks up the weld what could happen? A crack from the shoe weld through the pipe wall is one possibly.

 

[DriveMeNuts]

UW-5(a) and (b) may be helpful. It refers to welding to 'pressure parts' and 'non-pressure parts'.
The certification process is different and even not required for welding to either part type.

 

[DekDee]

SnTMan has given the best response.
If you are fillet welding something directly to a pipe containing pressure there are different rules / requirements than if you are fillet welding onto a compensating / reinforcement pad.
Socket weld - totally different scenario. Definitely a Pressure Retaining weld.
Just my 2 cents worth.