Can or cant horizontal piping be considered self draining
Can or cant horizontal piping be considered self draining
(OP)
I have a system of water flowing from and steam traced and insulted header, to a bare vertical run (~10 ft), turning 90 degrees to a bare horizontal pipe (~3ft), ending to an open ended bare nozzle pointed vertically.
The water is used to cool discarded material before being disposed of, so flow is opened only for a few minutes after each drop.
There's great debate as to whether the drop leg can be considered self draining or not, and whether it would freeze in winter time.
Does anybody has experience with a system like this?
Can an open ended horizontal pipe be considered self draining?
The water is used to cool discarded material before being disposed of, so flow is opened only for a few minutes after each drop.
There's great debate as to whether the drop leg can be considered self draining or not, and whether it would freeze in winter time.
Does anybody has experience with a system like this?
Can an open ended horizontal pipe be considered self draining?





RE: Can or cant horizontal piping be considered self draining
If it's not heat-traced, it will freeze anyway.
Mike Halloran
Pembroke Pines, FL, USA
RE: Can or cant horizontal piping be considered self draining
Example:
#1). 12"NPS may not be a problem
#2). 1/2"NPS is potentially a problem
RE: Can or cant horizontal piping be considered self draining
Practicality would suggest that the pipe have some nominal slope, so that draining could continue without the need for a driving head of liquid behind the flow, which would obviously leave small amounts of liquid behind the flow when the liquid head behind was no longer sufficient to drive liquid ahead of it forward. In other words, a flat surface can't drain completely.
Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso
RE: Can or cant horizontal piping be considered self draining
For freeze protection, horizontal pipe is considered self-draining. There will be much less than 10% liquid remaining.
For line-breaks, horizontal pipe is NOT self-draining. There will be a small ammount of retained liquid in the center of every support-to-support span.
RE: Can or cant horizontal piping be considered self draining