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plumbing venting question

PostPosted: Tue Apr 19, 2011 6:32 pm
by StandUpGuy
I think I have the layout worked out pretty much. One issue I have is with venting the toilet. I have a pop top in the works and am planning on fabric sidewalls with perhaps some mesh windows. The problem is I am not sure where or how I should bring up the vent stack so it does not get into the cabin. Any suggestions?

PostPosted: Tue Apr 19, 2011 7:31 pm
by Blotto Bros
this is just a thought but segmented hose like they use on shop dust collectors. When you drop the top it will flex and when its open it will stretch.

PostPosted: Tue Apr 19, 2011 7:41 pm
by StandUpGuy
Blotto Bros wrote:this is just a thought but segmented hose like they use on shop dust collectors. When you drop the top it will flex and when its open it will stretch.
Thats not a bad idea. No doubt the best place for the pipe to end is the highest point of the trailer that being the peak of the pop up. For that matter I could have a fitting end inside the trailer at the height of the closed lid position and have a vent mounted on the lid, then when I open it up I could have a rigid pvc pipe to put in place. Either way this lenth of pipe will be visible inside the trailer. It needs to look nice.

Somehow.

PostPosted: Tue Apr 19, 2011 7:51 pm
by StandUpGuy
Here is my current layout. I am thinking maybe the stack would come up in a bump out in the wall behind the sink. If there, it would be rather prominently positioned inside the cabin.

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By justoneman at 2011-04-19

PostPosted: Wed Apr 20, 2011 5:51 am
by bobhenry
1 1/2 inch schedule 80 pvc slides neatly into schedule 40 2" pvc. This would make a trombone slide that will extend with the top as it is lifted and retract when lowered. Since the vent is using thermal lift to vent it is very unlikely is could or would vent at the slide joint.

PostPosted: Wed Apr 20, 2011 6:42 am
by StandUpGuy
bobhenry wrote:1 1/2 inch schedule 80 pvc slides neatly into schedule 40 2" pvc. This would make a trombone slide that will extend with the top as it is lifted and retract when lowered. Since the vent is using thermal lift to vent it is very unlikely is could or would vent at the slide joint.
The pivot point would be about 4 + feet away from the vent location. There would be a lot of later shift in the raising of the lid. Probably on the order of about 6 inches. My lid is not a straight up top but rather a one sided angle lift.

PostPosted: Wed Apr 20, 2011 9:49 am
by bobhenry
Buddy and I ( both auto mechanics at the time) were sharing a house long ago and were remodeling the old bathroom. We had a large diameter line , Drain or vent I forget which , but there was no combination of fittings that would get us there so we went to work and cross referenced a non collapsable radiator hose with the correct I.D. ends. Maybe this would allow the stack to flex enough to still work ! :shock:

PostPosted: Wed Apr 20, 2011 3:35 pm
by aggie79
Have you thought about venting through the sidewall? Unless you're planning on some long stays, there won't that much sewer gas. Sidewall location should be good if you don't have a window too near the vent.

PostPosted: Wed Apr 20, 2011 3:56 pm
by StandUpGuy
bobhenry wrote:Buddy and I ( both auto mechanics at the time) were sharing a house long ago and were remodeling the old bathroom. We had a large diameter line , Drain or vent I forget which , but there was no combination of fittings that would get us there so we went to work and cross referenced a non collapsable radiator hose with the correct I.D. ends. Maybe this would allow the stack to flex enough to still work ! :shock:
For that matter I could make your trombone stack adjacent to the pop top. then after the top is up pull the stack up higher than the pop top. No real need to make the top and the pipe move together.

PostPosted: Wed Apr 20, 2011 3:57 pm
by StandUpGuy
aggie79 wrote:Have you thought about venting through the sidewall? Unless you're planning on some long stays, there won't that much sewer gas. Sidewall location should be good if you don't have a window too near the vent.


If that was acceptable that would be awesome. I am not sure I want to cut a hole in the side only to find out it does not work so well.

PostPosted: Wed Apr 20, 2011 3:58 pm
by StandUpGuy
Here is a cross section of the planned wall. the stack could emerge from the roof ledge next to the pop top.






Image
By justoneman at 2011-04-20

PostPosted: Wed Apr 20, 2011 6:26 pm
by StandUpGuy
What do you suppose? If I have the vent end on the roof ledge and then have a pop top next to it and I have a fabric wall by the vent, will the fabric stop any smell from getting in? I could make it plan fabric, say nylon and have no mesh window on the vent side of the trailer.

PostPosted: Wed Apr 20, 2011 6:34 pm
by StandUpGuy
I have aquired a toilet but have yet to get the toilet flange. What is the drain pipe diameter that is standard for RV toilets?

PostPosted: Thu Apr 21, 2011 10:00 pm
by jeprovo
I think you should put the vent up through the roof ledge, like you're planning. End the vent a threaded fitting, like this:

Image

Then make an extension pipe with a fitting like the one below, to thread into the tube sticking out of the ledge. When you are camped and raising the top, thread the extension pipe in to raise up the vent pipe.

Image

PostPosted: Fri Apr 22, 2011 6:36 am
by Shadow Catcher
You could run the vent line boxed, up to the roof line and run nylobraid or clear hose from the end of the pipe up to the roof vent. You only need about a 3/4" line and a couple of hose barbs.