Roof Drain Flow Rate
Published flow rates for Froet Roof Drains
roof drain capacity calculation
The below flow testing results are for Froet Drains only. Do not use this information with any other drain. Do not assume there are any
similarities with any other drains. The flow testing results are to be use in combination with your existing piping calculations, these are not
a replacement of the pipe flow results.
Another important point to understand is that you should only use the GPM values up to the very low negative pipe pressures (10ft Pipe Chart)
not past -5. If you notice the drain only testing and the begining of negative pipe pressures in the 10 foot pipe chart correlate closely. As
the negative pipe pressures begin to increase is when the siphonic pull is begining in the pipe and can lead to damaging pulsating vibrations
in the piping system as it increases.
Froet feels that the drain only values are safe GPM's values to use. You will notice some anomalies in these charts that don't seem to make sense.
Until a testing lab is able to test drains again we will not be able to test to try to correct these issues.
Froet Industries feels it is important to get this information to the enginering community so we have posted as it is. This should give you information
to help you design your drainage systems correctly. If you have any questions in regard to this information please call Froet Industries.