Galley tank vent

[jsmith948]

Up on the roof checking/recaulking the other day. Hard to get a real good look at the Dicor around the refer flue so I removed the 'bonnet' .
Hidden inside the refer 'chimney' is an ABS vent pipe. Judging by how the pipe is angled, and given that the grey and black vents are visible forward of the galley on either side of the roof, this vent is obviously for the galley tank. Just thought I would pass this info along. Maybe it is nothing new to most of you, but, I have read threads regarding the 'cheater vent' under the sink(we have this cheater vent under the sink also) being the only galley vent. I had bought into there being only two vents (grey and black) until I discovered this vent hidden under the refer cap.
BTW, when I removed this cap, found some cracks in the Dicor. Might be something you would want to look at.

Added: I wonder what could happen if I left the galley tank dump open while hooked up to the CG sewer. Would the sewer gas travel up the galley vent? Is it far enough above the refer flame? Ah, couldn't happen. Marty, when you come out, bring me another cool one?

[bobbecky]

It is not wise to leave any drain valve open while in a campground, unless you configure your drain hose with a dip, enough to trap water in it, to prevent sewer gas from venting from the campground sewer system. You also risk getting a buildup of kitchen waste in the galley tank by not having a good flush when draining the tank, which would carry the debris out.

[jsmith948]

Yeah, I get that. I was attempting to be sarcastic.
Thanks for response. The point I was trying to pass along was that, at least on our trailer, there is more than just the under sink cheater vent.

[Outback 325BH]

FYI: The "cheater vent" under the sink is to allow air into the drain pipe. It prevents the siphoning of the p-traps. In normal plumbing, there would be a pipe there connecting to the vent -- like in a home. That one-way vent is used due to space constraints and logistics of running another pipe.

The main vent stack, which could serve double-duty for the venting I mentioned above, is to allow air to escape as the tank fills with liquid. The air has to go somewhere, otherwise pressure would build and prevent the sink from draining.


Sent from my iPhone using Tapatalk

[jsmith948]

Got it -makes sense. Just a good example of how we can sometimes be mislead/misinformed by . Anyway - glad I looked under the refer's chimney cap. The cracks in the Dicor would have eventually leaked.