Half above / half below floor drain

[jimmyhutmacher]

Hello,

The attached sketch shows a drain style where half the pipe penetrates the shell above the floor and the other is half below and penetrates through the floor. I'm aware this detail is not included in API 650, but is fairly commonly used in the industry. Any thoughts on what tanks (considerations for size, environmental conditions, contents, etc.) you feel comfortable using this detail on? Tanks you do not? Aware of any engineering resources for this drain style?

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1696446229/tips/Drain_oxxmfi.pdf[/url]

Thank you

 

[mk3223]

IMO, I am not aware of this type of the nozzle in the O&G production or refining plants. It looks that it's the one design of the low point drain nozzle in the tank sloping bottom.
Instead, is it simpler to use a tank bottom drain nozzle outlet with a below grade sump for collecting the tank drainage?

 

[JStephen]

I've seen details like that, also a similar detail making a flush-type connection using an eccentric reducer sliced lengthwise.
I think API should consider including a detail like that, with application limited to small/low-stress tanks, but not aware that it's in the works.
The main issue with stuff like this is people specifying non-API-650 details, then turn around and want an API-650 nameplate on it.
Where I normally see things like this is in "miscellaneous stuff storage", ie, not in refineries or oil-related industries.

 

[jimmyhutmacher]

mk3223,

Thank you for the input. Are you referring to the under bottom connections detailed in Annex O?

JStephen,

I've heard of the eccentric reducer style as well. Any specifics on what you'd classify as a low stress tank? Maybe <0.5*Sd in the tub ring?

 

[mk3223]

Are you referring to the under bottom connections detailed in Annex O?

Yes, API-650 Annex O is the under-bottom connection which can be used at tank low point drain outlet.

 

[Dhurjati Sen]

Better to opt for a siphon drain.

DHURJATI SEN
Kolkata, India