I've got some confusion that I'm hoping someone can help me clear up. I have a pool for which the original engineering data sheet specifies 44 US GPM @ 76 ft. TDH. I presume the TDH figure is correct, since this is the original engineering. The original pump model is unspecified, but would be of little concern anyway. The current pump is a Hayward Super Pump 1 HP, fairly new.
Now the thing is, Hayward's data for a 1 HP Super Pump doesn't even HAVE a value for a TDH of 76 ft - it drops off completely past 60 ft.
(see brochure: http://www.hayward-pool.com/pdf/literat ... mp10_4.pdf or http://www.hayward-pool.com/prd/In-Grou ... 002__I.htm / Specs tab ).
What's the problem? I have an actual flow rate of 58 GPM, which is way above spec and likely to get me in trouble with the health authority (large increase in water velocity creating a suction hazard). By Hayward's spec sheets, I should have something akin near zero with the installed pump.
What is going on???
A little more information: The pool is 18,200 gallons, sucks from a pair of main drains (via one line) and two skimmers (each with their own line). There are four returns. The filter is a Hayward S-244T capable of up to 63 GPM.