Installing Rainbow 320 Chlorinator - Do I need optional check valve installed?

I do not have a heater and understand the 320 has a built in check valve. The PVC does feed into metal pipes (used to have a heater). Confused about the optional Pentair check valve R172288. Do I need to buy one and install at same time I install the chlorinator? Is it even necessary? and if so, can I add it later?

It is an inground pool, 2" PVC.

Thanks - Bob

Sorry that I am not the one who can help you with this particular question, but just wanted to welcome you to the Pool Forum!

Thanks Watermom for the welcome! I went ahead and installed the chlorinator without optional check valve. The PVC pipe was not that long, but I think I left enough room for the Pentair check valve just in case. From reading, it looks like it is a 1.5" valve that fits inside 2" pipe... this may restrict water flow a little. Since I don't have a heater, I think I may be OK as is. My only concern is on the flow to pool side of the 320, the PVC connects to metal pipe that feeds the water to the pool.

And thanks for this forum! I've learned a lot just from reading posts.
Bob
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