Flush type clean out door height

[inammanj123]

Dear All,

For flush type clean out door of size 36" X 48" I am using an insert plate of 18 mm thick and 1747 mm height( 1372 + 375), and the adaject shell course thickness is 14.5 mm thick AND 2475 mm height . My question is there any requirement that says that height of insert plate for flush type COD be same as height of adjecent shell course height. In figure 5.12 of API 650 12TH Ed. at the top it says "nearest horizontal weld". What is the significance of this.


Regards,
Inam

 

[IFRs]

5.7.8.3 says the cleanout shall be assembled into a "shell plate". Reading ahead, we see in 5.7.8.3 that a flush nozzle shall be assembled in "a shell plate or insert plate". This suggests that a cleanout must be in a full-height plate which must be at least 375mm higher than the reinforcing plate but a flush nozzle can be in a full-height "shell" plate or a shorter "insert" plate.

 

[JStephen]

Normally, the insert plate would be the full height of the shell ring. The significance of showing the "nearest horizontal weld" is that in some cases, that will limit the height of the shell course. For example, if you are using a 48"x48" manway with 72" high repad, then you can't put it in a 72" high shell course.

I'm not sure if there is anything in the standard that specifically prohibits using an insert plate less than the shell course height, or of, say, stacking two 5' wide plates and welding into a 10' high shell course, but it's not the expected construction.