Is My RV Black Water Pipe a Standard Diameter

Question:

I have a 2020 Coachman Brookstone 344FL and like the idea of your T58 Valterra twist-on waste valve but dont know if my drains are 3 or larger. I would think they would be standard size but the cap measures about 4 and the OD of the pipe is over 3 but I am thinking the ID is the measurement and that could be 3. Am I correct in my thinking and if not how can I determine the size?

asked by: Gary M

Helpful Expert Reply:

Your thinking is 100% correct here. RV black water drains will be a standard 3" size, which is the internal diameter of the pipes, so the Valterra Waste Valve for RV Black Water Tank - Twist On - 3" Bayonet Hooks to 3" Lug # T58 will work on your black water tank pipes.

expert reply by: Erik B