question about black water plumbing parts
Outfitting a resto-mod AS. Starting from scratch.
I purchased an above the floor combo shower pan toliet base. It has an above the floor black tank. But the black tank is really small. I have also purchased two 25 gallons waste tanks from Inca. One for black, one for grey water.
My plan is to place a slide valve below the above floor tank, and then run 3" to the 2nd tank. The idea is to use the second tank as a backup. When the first is full, pull the valve, drain it the second, and then close the valve.
I think the parts from the bottom of tank one to the second tank are: (1) valve (2) 90 (3) length of 3" pipe (4) another 90. Looks like I also need a hub for each side the Valtera slide valve.
Here's my question, sorry if its a dumb one. Looking at Valtera parts, I don't see a plain 90 or any 3" pipe. Is there a reason for this? Or is that one assumes you just use regular 3" PVC you can by at the hardware store?