[Wavery]

  The straight one would work. You could drill your hole through the wall inside the sink cabinet then use that flexible hose that they use on garbage disposal vents.

https://www.amazon.com/Universal-Dis...%2C192&sr=8-28

[Deb Mac]

Unfortunately, I already have my hole drilled and the 1/2” valve in the wall. However, I have tracked down a 3/4” one on amazon (never showed up before) as well as a 1” one on eBay. I have both coming. I’ll see which one is easier to retrofit.

[Wavery]

Before you drill a hole for the 1" vent, be sure that you can find 1" hose. 1" is hard to come by.

[Deb Mac]

No worries 👍

[Bill]

Originally Posted by Wavery

It would be so easy and cost effective for TM to have a custom, drop-in, black water tank made. Once the mold is made, the rest of the process is easy. They could even have blow-mold tanks made. They are relatively cheap and easy. There are a lot of companies that will build them (in bulk) from dimensions over the internet.

You are right - TM could easily make and install a black tank, but that is not the issue. The difficulty that TM faces is that plumbing code, including RVIA code for campers, requires the black tank to be vented through the roof. Venting through the sidewall or floor is expressly forbidden, as is any design that requires action (such as connecting a pipe) by the owner/user. In a folding trailer, this is a nearly impossible requirement. TM has struggled with this since Thetford discontinued the recirc, and has not yet (in my opinion) found a good solution.

Bill

[Wavery]

Originally Posted by Bill

You are right - TM could easily make and install a black tank, but that is not the issue. The difficulty that TM faces is that plumbing code, including RVIA code for campers, requires the black tank to be vented through the roof. Venting through the sidewall or floor is expressly forbidden, as is any design that requires action (such as connecting a pipe) by the owner/user. In a folding trailer, this is a nearly impossible requirement. TM has struggled with this since Thetford discontinued the recirc, and has not yet (in my opinion) found a good solution.

Bill

They figured out a way to do it when they started installing the Sealand toilets.
However, it wasn't very attractive nor was it very creative. I think that it could be done with PVC pipe.

[Bill]

Is that the one where they run a piece of PVC pipe from the black tank, through the bathroom wall into the space under the kitchen sink, and then run a length of dryer hose upward along the interior wall above the sink, to a vent fitting through the roof? I never liked the idea of running a bathroom vent hose above the food prep area or the clean dishes that I just washed. It was code-compliant, but as you say, not very attractive. On the other hand, I couldn't think of a better way.

Bill