Herbie Drain

[sphelps]

For the emergency drain using a larger pipe of 1.5" above a 1" bulkhead is actually ideal if possible. A 1.5" riser will flow more water than a 1" riser despite the bulkhead being 1" for both cases. Same rules apply to standpipes, usually for best results your standpipe should be one or two sizes larger than the bulkhead. This just allows higher flow at the entry point which has zero head pressure as appose to the bulkhead which can potentially have head pressure equal to that of the standpipe height.