Sizing Heater Connections and Bypass

[rscam]

Hi. I'm in process of installing a new heater (Raypak 336A) with a manual bypass. All of my existing plumbing is 1-1/2" so I plan to use Jandy Diverter and Check valves (see attached) using their 1-1/2" inside connection and to run 1-1/2" pipe to my heater. I'm questioning whether it would be worth it to use 2" pipe for my heater and bypass connections (I would buy the larger 2" inside connection valves) instead. If I did, I would immediately reduce to 1-1/2" upstream and downstream of the heater/bypass assembly.

I wonder if I would actually notice much of a difference between the 1-1/2" and 2" install from a heater performance or flow perspective considering all other piping will remain 1-1/2". My pad is pretty tight so I think the 1-1/2" will be easier to squeeze in (otherwise I'd just go with the bigger pipe)

I included a picture of my existing plumbing. Note that the existing heater is not part of the plumbing now (it was bypassed when it failed) so what you see in the picture is the 1-1/2" supply from the pump/filter rising from underground, space for the swg, and then back underground to the pool returns.

On a side note, I'm not sure if I need a 1/2 lb or 2 lb spring in the check valve.

Thanks for the help
Ron

 

[Ahultin]

I would run all of the new in 2" but use the 1.5x2 diverters for simplicity. On the heater side you use a 2" coupler, on the other side you can use the 1.5 slip, saves you money on reducer bushings as well. . If you upgrade anything else later (swg etc) you can cut the slip flush and use the 2" coupler. For the check valve I just used the standard jandy ones that don't give a # rating.

 

[rscam]

Thanks for the advice, Ahultin, I'm going to do it the way u suggest. Makes sense.