API 650, Shell Plate Horizontal Weld

[MOHAMMED89]

Dear Friend,

I have one doubt regarding the Shell Plate Horizontal Weld.

Bottom shell course is 22mm thk and adjacent above shell course is 16mm thk, So my question is if we are chamfer the 22mm plate to 18mm and Weld this 18mm to 16mm with double bevel butt weld. So what will be the chamfer slope?? For double bevel butt weld in this case what angle should maintain for the weld?

Tanks in Advance

 

[JStephen]

See Figure 5.2 for typical weld configurations. API-650 doesn't specify a transition bevel in this case, so it doesn't specify the slope. I think ASME and API-620 specify slopes for that chamfer if used.

 

[IFRs]

If you align the plate centerlines, there won't be as much

 

[valleytank]

Like IFR's already stated. If this may be a centerline-stacked configuration you should be able to split the difference and not worry about a transition with those numbers. If however you require the inside to be flush then I believe the 4-1 TAPER would apply as you are out over 1/8" of an inch on the outside.

 

[IFRs]

There is no requirement in API 650 to bevel the thicker plate in a horizontal joint if the thicker plate is the lower plate in the joint. The default condition is center stacked. In contrast to vertical shell joints, horizontal shell joints have little stress in them. Horizontal joints do have to have complete penetration and fusion.

 

[MOHAMMED89]

Thanks all for your advice

So when we joint(Horizontal) 8mm plate to 6mm plate , Single bevel Butt joint or Square Butt joint which one is better??? API 650 didn't specify the Type of weld.

 

[IFRs]

For manual SMAW or GMAW I'd use a 45 degree bevel on the outside of the upper plate, no bevel on the lower plate, a 1/8" land on the upper plate and an 1/8" gap between the plates. But your weld procedures should cover this and may be different.

 

[MOHAMMED89]

Thank You IFRs

 

[Duwe6]

In USA, the traditional method is to use 'key-plates' that give a 2-4mm gap, and leave the plates square cut [no bevel] E6010 or SAW is used for the weld [deeply penetrating methods], and the 2nd side is backgouged to sound weldmetal using CAC 'air-arc'. Works very well, much faster than beveling.