Flow rate of various size pipe

[AHHope]

ive been searching everywhere to find the flow rate of a 1 inch and 2 inch overflow pipe
thanks

[xtreme]

Try this chart.

http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml

[AHHope]

awsome thanks thats exactly what i was looking for

[mark]

see often 1" will drain 600 gph (RC calculator (http://reefcentral.com/index.php/drainoverflow-size-calc)) with no pressure, but there are other factors. eg I've got a 1" bulkhead on a shallow CtoC and can only get about 300 gph.