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Unread 04/07/2010, 06:13 PM   #7
uncleof6
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billdog, the chart that you posted concerns blank bulkheads, and does not consider interaction with the standpipe. Max flow capacities for bulkheads, or even pipe sizes is relevant to the discussion, but not in the way you are presenting it. The issue is laminar vs turbulent flow. Laminar flow, that will be silent, bubble free, will be far below any max capacity of a given size bulkhead, OR given size stand pipe. The bubbles and noise annoy most people, and the number of threads on the subject far to numerous to ignore. There is a commonality, that can be seen even if the physics are not understood-- or even known. It is always because the flow rate is too high, and/or restrictions in the drain line. A 1" air/water mix standpipe will have problems way below 300 gph, and the inventor of the "durso" states clearly that a 1" durso, is of no real use-- except with extremely low flow rates. My comments have nothing to do with max flow through a bulkhead, through a particular size pipe, or with siphon systems. An air/water mix standpipe flow goes up, thinks about siphon, the "toilet flushes" = flow rate too high. Flow in the standpipe is not laminar (noise, bubbles with or with out "toilet flushing" = flow rate is too high. Laminar flow in a standpipe, is very low relatively speaking. The physics win.

I think before this gets too far, and the OP goes away, give the OP a chance to address the question of what the exact issue is, if there even is one. He stated "i believe my return pump is to strong," that is only telling to a point.

Jim


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