Nozzle to Shell Weld

[solidhardhead]

When a ASME code welder welds around a nozzle the angle between the shell and nozzle varies. The fillet weld size called out on the weld symbol represents that weld at a 90 degree angle. But you will not get the same weld throat you at the 90 degree angle when you get around to the 120 or 130 degree angle if you keep the weld legs the same throughout.

How do I make sure that my weld throat stays consistent all around the nozzle???

 

[gtaw]

Try sketching the joint details, including fillet weld, to scale.

Depending on the ratio of the shell to the nozzle, the angle between the shell and the nozzle at the side zone can vary. The larger the angle, the smaller the throat for a given leg dimension.



Best regards - Al

 

[solidhardhead]

When a weld symbol is used it is defining the weld size and throat at a 90 degree angle (which results in a overall area of weld). Shouldn’t the welder use this as a basis for establishing the throat needed on the nozzle and therefore realize he has to build-up the weld as the angle increases in order to meet the weld throat and weld area established at the 90 degree angle? After all, not only is the throat being compromised but so it the overall area of weld if the legs are not increased.

If I took your suggestion and made a detail, what angle do I make it for? And how many details do I make?

Thanks

 

[gtaw]

Yes, the throat dimension is the dimension of interest. Most ASME codes show the throat dimension in their figures, not the leg.

The AWS welding symbol uses the leg dimension, but as you noted, the throat dimension will get smaller in the side zone unless you increase the leg to maintain the required throat.

Best regards - Al