Weld size in pressure vessel

[MGZmechanical]

Hi, we're designing a pressure vessel and after performing the calculations there is one part that with 8 mm thickness is enough (corrosion allowance already included). Going to the next standard plate of 10 mm the weld thickness (two sides) is 0.7·10 = 7 mm which we can make in a single layer.
In this Project we have many parts in 15 mm thickness so we've decided to standarize thicknesses to 15 mm also for the part of 10 mm.
Now my doubt is, the welding of that part should be based of the nominal thickness of 15 mm(10.5 mm) or can I make it based on the mínimum required thickness?

All the standard seem to be based on nominal thickness but this would be overwelding a lot.

Best regards.

 

[TGS4]

What Code are you designing to?

 

[david339933]

I think a little more explanation is required.....where are you getting .7 x 10 = 7mm?

 

[racookpe1978]

If the two intersecting plates are each 10 mm (3/8 nominal), a standard fillet leg is also 10mm

But the Euro convention is to size fillet welds by throat dim, which is approximately .7 x 10 mm. (0.707 in a CAD world.)

 

[MGZmechanical]

Hi, I'm designing to EN 13445-3 (european code equivalent to ASME VIII). All the fillet welds are according the throat size what is 0.7·min thickness. But in this case I'm using a minimum thickness oversized due to constructional issues. So, do I have to oversize the weld? Does it make any sense?

Thanks

 

[SnTMan]

Don't know the first about EN 13445-3, but if the required weld size is referenced to the nominal or actual material thickness, then the weld must be sized accordingly if it is to meet that Code.

Simple, really.

Regards,

Mike

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

 

[GenB]

You don't standardize all the welds to the same size.each weld is assess according to the size of each component welded. In most cases the Tmin rules which is the smaller of the thickness part to be welded to and then calculate accordingly. If some of the parts are of similar but differ a little then the use of a thicker weld can apply to all. In Your case you say it will become too thick to on the smaller parts. Well, you are creating your own problems in the design. it's the Code.whatever Code you're using. Regards

General Blr. CA,USA

 

[chicopee]

You have not described which part of the pressure vessels you are welding, however, I hope that you are not overlapping plates and fillet welding them to fabricate drums.