What Adapter and Hose do I Need to Drain My Gray Tank with 1 1/2" Drain Hole?

Updated 01/16/2026 | Published 01/12/2026

Products Featured in This Question

Valterra Gray Water Drain Connector - 1-1/2" FPT to 3/4" Hose Thread

(132)

$8.35

Valterra Gray Water Drain Connector - 90-Degree - 1-1/2" FPT to 3/4" MPT

(132)

$8.76

Valterra Flushing Hose for RV Sewer System - Gray - 1/2" Inner Diameter - 15' Long

(72)

$20.19

Question:

The grey water discharge on my camper is 1.5 inch. Do you have 1.5 inch hoses of any length or a fitting to connect to a 4 inch hose?

asked by: james b

Expert Reply:

Hello James,

I have a great set-up for you. You will want to use the Valterra Gray Water Drain Connector - 1-1/2" FPT to 3/4" Hose Thread # T01-0094VP, or if you need a 90 degree option, the Valterra Gray Water Drain Connector - 1-1/2" FPT to 3/4" Hose Thread - 90 Degree # T01-0091VP.

You will want to pair that with the Valterra Flushing Hose for RV Sewer System - Gray - 1/2" Inner Diameter - 15' Long # W01-4180. Since the gray water tank only has used water and not waste in it, you can safely use the smaller diameter hose. It also helps that the hose is gray to remind you that it is not for drinking water.

What kind of camper is this for, and what trip are you most looking forward to this year?

expert reply by: Kate F

Dimensions of T01-0094VP
(click to enlarge)

Toms

1/14/2026

The problem I had with the Valtera adapter is that there is an initial unthreaded section of the male fitting that prevents the threads from engaging the typical female hose connector. I had to grind that section of the Valtera adapter back to allow the threads to engage. Once that modification was made it worked fine.

Kate F.

1/15/2026

@Toms I am sorry to hear that Tom, sounds like maybe a bad batch went out. Thanks for the response, and I am happy to hear you found a way to make it work.

James B.

1/15/2026

Thank you. I have already been using this setup, but at campgrounds where I am able to connect to a sewer line, it would be more convenient to use a 4 inch connection. Running the small hose through a 4-inch line is cumbersome.

Kate F.

1/16/2026

@JamesB Got it James. I reached out to my friends at Valterra to see if they have something they can suggest so we can make your life a little easier. I might not hear back from them til Monday, but I will let you know as soon as I have some part number for you.