Do I need a valve on sump plumbing?????

[Blom]

Originally Posted by sphelps

so what's the velocity?

Well ideally you would measure this lol, but I dont see that being practical in this scenario. You could do this the way the pdf I posted goes about it, but this would be tough to find tables for as our elevation changes are small, or so I assume. Another way to do this would be to estimate the velocity based on gravitational acceleration:

9.81m/s^2
OR
32.2ft/s^2

Time how long it takes from the first overflow trickle till when its out of the piping. For example say it takes 2.5 sec to flow through, this would translate into a velocity of 24.5m/sec. This can give a ballpark figure. The more water volume on top of the intake though will create some head pressure, which then changes all of this. This assumes gravity fed drainage into atmospheric pressure.

Im sure if you google it someone has done the math!