Fixed tubesheet with drain/vent drilled out the side
Fixed tubesheet with drain/vent drilled out the side
(OP)
Hello all. I am looking at a vertical shell and tube heat exchanger built to ASME code Section VIII, Division 1 and stamped. The shell is 20" in diameter. The tubesheets are extended as a flange for bolt-up of the tubeside channels.
Each fixed tubesheet has a drain/vent drilled into it.
To elaborate, a 1/4" diameter hole is drilled into the shellside face of the tubesheet to a depth approximately 1/2 the thickness of the tubesheet. A 1/4" diameter hole is drilled radially in from the OD of the tubesheet to meet the other hole. At the OD of the tubesheet, there is a larger hole bored out to fit a 1/2" pipe. (socket weld connection). The purpose is to drain at the bottom and vent at the top.
So my question... has anyone ever seen a reference that addresses this? I've seen it done before, but I have never seen it addressed in Section VIII or any other reference out there for tubesheet design. I'm just curious how someone goes about accounting for this in their tubesheet design.
Each fixed tubesheet has a drain/vent drilled into it.
To elaborate, a 1/4" diameter hole is drilled into the shellside face of the tubesheet to a depth approximately 1/2 the thickness of the tubesheet. A 1/4" diameter hole is drilled radially in from the OD of the tubesheet to meet the other hole. At the OD of the tubesheet, there is a larger hole bored out to fit a 1/2" pipe. (socket weld connection). The purpose is to drain at the bottom and vent at the top.
So my question... has anyone ever seen a reference that addresses this? I've seen it done before, but I have never seen it addressed in Section VIII or any other reference out there for tubesheet design. I'm just curious how someone goes about accounting for this in their tubesheet design.





RE: Fixed tubesheet with drain/vent drilled out the side
The Code (S VIII, Div 1 anyway) recognizes that areas of stress concentration exist, and design rules are generally conservative enough that these concentrations can be ignored.
Regards,
Mike
RE: Fixed tubesheet with drain/vent drilled out the side
Our design codes for this type heat exchanger are data form the 50's and were copied from earlier design codes from DuPont.
RE: Fixed tubesheet with drain/vent drilled out the side
RE: Fixed tubesheet with drain/vent drilled out the side
rmw