1 1/2 Pump Inlet/Outlet with 2" Plumbing

[TellyDSP]

I recently had my old pump (WhisperFlo) take a dump while restarting after Irma. It came with the house and is probably 10-14 years old. I decided to replace it instead of diagnosis. Thinking I'm smarter than I am, I just went off the fact that my backwash pipe is 1 1/2 and ordered a pump with the same HP as the old and 1 1/2" pipe spec. I just went outside to install the pump and found that the pool is plumbed with 2" pipe. Will using a pump with 1 1/2 in/out on a 2" system cause issues. I have a SWG, propane heater, and in-floor cleaning system attached.

Trying to see if I should keep this pump or go through the hassle of an exchange. TIA.

 

[scooperhsd]

Won't present a problem, as long as you have the reducing adapters in place.

If you bought a Pentair pump - the Superflo are maybe 1.5 inch screw in, but they come with union fittings that can take either 1.5 OR 2 inch. It would not surprise me if the Whisperflo are the same.

 

[TellyDSP]

Thanks. Having that choke point at 1 1/2 wont cause pressure issues down the remaining 2" lines? Looking at the available pumps in 1 1/2 HP, most use 1 1/2 in/out, unless I get another WhisperFlo. Even the Pentairs that have the 1 1/2-2" combo union fittings, have the pump in/out threaded for 1 1/2 male threaded fitting. It looks like even if I went that route, the ID of the pump body in/out is still only 1 1/2". They're labeled as "Unionized fittings (1.5" internal slip and 2" external slip)". Sounds like the plumbing either slips over the union fitting(2") or inside it(1.5").

 

[jblizzle]

What pump did you buy? Just looking at HP is not the whole story. The Whisperflo is a large high flow pump. If you got a smaller pump, your flow rate may be significantly less even with the same HP motor just due to the pump design not the "choke point" which is not really a thing.

The external slip means that that a 2" pipe is exactly the same outer diameter as the fitting and you use a 2" coupler to attach the fitting to the pipe.
Alternatively, a 1.5" pipe will slip directly into the fitting.

 

[TellyDSP]

Hayward Superpump. I was trying to save some money, but now I'm thinking I should just get the Whisperflo. With the in-floor cleaner and SWG, I'm afraid of losing too much pressure in the system if the Whisperflo is that better of a performer.

EDIT: I just went down the google rabbit hole with this and learned about THP.

The pump is a WF-26(I think now the WFE-26). So I guess it's the uprated model.
1.5 HP
1.1 SF
1.65 THP

This should give me what I need to make a decision, as long as the fitting size doesnt affect the output numbers. The SuperPump I bought is 1.5 HP/1SF, so a THP of 1.5. Is there a huge difference between the Whisperflo 1.65 and SuperPump 1.5?

Also, it looks like the WFE-4 (Full Rated 1HP) and the WFE-26 (UpRated 1.5HP) have the same THP. So, is one more energy efficient than the other?

 

[jblizzle]

Those 2 Whisperflo models are identical. Just marketing.

Even if you got a 1.65 THP Superflo, it would move less water than the Whisperflo.

Compare flow rates at a given head loss in the head curves.