API 650 Upper plate thicker than lower plate
API 650 Upper plate thicker than lower plate
(OP)
API 650 11th Edition Section 7.2.3.2: The upper plate at a horizontal butt joint shall have a 4:1 taper when its thickness is more than 3 mm (1/8 in.) greater than the lower plate.
When would the upper shell plate be thicker than the lower plate?
Does API offer guidance when the lower plate is more than 1/4" thicker than the upper plate?
When would the upper shell plate be thicker than the lower plate?
Does API offer guidance when the lower plate is more than 1/4" thicker than the upper plate?





RE: API 650 Upper plate thicker than lower plate
That's the only situation that i can think of.
RE: API 650 Upper plate thicker than lower plate
It could also come up where a corrosion allowance is higher for the upper course than the lower course.
RE: API 650 Upper plate thicker than lower plate
I agree 100% with both of your comments. It is very common to taper the edge of a thickened insert when the insert plate is more than 1/8" thicker than the shell, they are almost always installed flush inside.
What do you think should be done when the lower plate is more than 1/4" thicker than the upper plate so when center stacked (the default condition) there is more than a 1/8" change in thickness at the joint? Is this covered anywhere in 650 or 653 (I could not find it).
RE: API 650 Upper plate thicker than lower plate
1st course - 1.105"
2nd course - 0.850"
3rd course - 0.637"
4th course - 0.433"
5th course - 0.375"
The greatest offset being exactly 1/4". This allows, like you said, 1/8" on each side.
RE: API 650 Upper plate thicker than lower plate
RE: API 650 Upper plate thicker than lower plate
RE: API 650 Upper plate thicker than lower plate
Section 7 is dealing with construction issues including plate alignment.
RE: API 650 Upper plate thicker than lower plate
Section 5.6.1.3 does not cover my situation.
Section 7 does not cover my situation either.