I've been reading this forum, and found it to be the most helpful one thus far! Thank you to all who donate their time and expertise on this forum. I am seeking advice on the choice of a pump and have a question regarding pipe/valve sizing. Here is our current pool info:
-inground, vinyl, installed in the mid-80's (we are not the original owners)
-oval, approx 18 x 36, 20,000 gallons
-used only in summer (we live in New England)
-one skimmer, 2 returns, no main drain
-filter: American Titan vertical grid D.E. filter (model 582090). Label says flow rate for a private pool is "w/o slurry 90gpm, w/ slurry 108gpm"
side mount 8" centerline multiport valve (which we are replacing): American Products Americana. Pentair replacement part #50181312 (for 2" plumbing) or 50181212 (for 1 1/2" plumbing)
-pump: single speed, looks like a Hayward super pump, based on appearance of leaf basket, but no label. Motor (which was replaced at one time, so not original to pump) is labelled AOSmith model C48L2N131A1 1HP 170/85 amp *no gpm, but shows FR 56J - is FR "flow rate"?
Question 1: Pump has died. Is a 1hp pump an appropriate replacement. We will buy another single speed pump - would you recommend a Hayward super pump?
Question 2: We are replacing the multiport valve, which has cracks in the housing, in addition to all kinds of leaks. The Pentair multiport valve mentioned above will fit our filter. We will also be repiping, because many repairs over the years have yielded a messy setup with little room to make new repairs. My question involves the piping. The rigid pvc pipe of the suction and return lines are 2". The connectors on the filter are for 2" pipe. But the pump has 1 1/2" connections. So, the setup went like this: 2" pipe from the skimmer was reduced to 1 1/2" connection to pump. Pipe from pump was 1 1/2", and went into multiport valve with 1 1/2" openings. Pipe going from multiport valve to filter had a fitting that expanded it to 2" again. Pipe exiting filter was 2".
It appears that most 1hp pumps come with 1 1/2" openings, so we may have no choice but to reduce the suction line to 1 1/2" to go into the pump. The Pentair multiport valve can be bought with 2" or 1 1/2" connections. In your experience, do you think it matters whether we plumb to go back up to 2" immediately after leaving the pump and before a 2" multiport connection, or should we do what was done before and reduce to 1 1/2" before the pump and not go back to 2" until the water leaves the filter? I have the 2" Pentair multiport valve in hand, but will exchange it for the 1 1/2" if that is the better way to go.
Thank you for your advice.