Page 1 of 1

Question about venting gray water...

PostPosted: Mon Feb 06, 2017 9:59 am
by RandyH
I'm not using gray water or black water tanks in my conversion. I will use a porta-potty and a wheeled portable tank for the gray water when not using the campground sewer. My question is, do I still need an outside vent for the shower and sink? If yes, can I run the vent under the trailer and not through the roof? I don't want to put more holes in my trailer than necessary.

Thanks,
Randy

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 11:18 am
by lrrowe
My shower drains direcrly to a 5 gal holding tank. Or if at a campground, I run a garden hose directly to the campground drain.
I have no vent and none is needed for me.

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 3:49 pm
by flboy
As I understand it, the tank needs to be vented to relieve air pressure created by water flowing in and displacing it. Without a vent, it will push back and cause drains to gurgle and etc.. Just make sure your portable tank has a release of some sort.. or just don't make the hose air tight. I think the sewer is already vented... just make sure you have traps on your sinks and etc so you are not smelling the campground sewer. :-)

I think the same is true for air admittance valves... I'd have to think about that more however.. not sure about your plumbing configuration and if you would have downstream plumbing causing your up stream traps to clear? You could try it without. They are easy enough to add after the fact. Or you could buy the more expensive hepvo valves for your drains and forget about traps.

Sent from my SM-G935P using Tapatalk

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 4:09 pm
by RandyH
ok, my system is fairly simple, just a kitchen sink and a shower. I was thinking of using 1 1/2 piping for the drains. The sink will have a trap underneath and the shower a trap under the trailer. So I think I should be good. Thanks, for the help...

Randy

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 5:55 pm
by lrrowe
With the 5 gal jug, there is plenty of opening space for the down drain, therefore no back gassing or flow resrtiction.
For the garden house approach, There are dips in the line from the CT to the campground pipe which serve as a trap. No sewer smell yet. Overall, a very simple set up. I have no inside sink also.

Image

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 7:24 pm
by flboy
lrrowe wrote:With the 5 gal jug, there is plenty of opening space for the down drain, therefore no back gassing or flow resrtiction.
For the garden house approach, There are dips in the line from the CT to the campground pipe which serve as a trap. No sewer smell yet. Overall, a very simple set up. I have no inside sink also.

Image



That drain in the picture has a built in trap. It is what I am using in my shower also. Works great.

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 8:22 pm
by lrrowe
Forgot that...yes it does. Another explanation for why I am getting no sewer smell.

Re: Question about venting gray water...

PostPosted: Mon Feb 06, 2017 8:46 pm
by Padilen
I have the same drain on my shower and sink. No traps or vents. I do have a vent on my black holding tank.


Sent from my iPhone using Tapatalk

Re: Question about venting gray water...

PostPosted: Tue Feb 07, 2017 2:53 am
by Iconfabul8
The only problem I see that you might need to be aware of, is the draining water (especially through a small hose) can form a vacuum and suck the p traps dry. Possible solutions: Hepvo, install vent, or fill the p trap back up with water if it happens.

Re: Question about venting gray water...

PostPosted: Tue Feb 07, 2017 10:11 am
by RandyH
ok, good. How are you connecting to the campground sewer? I believe it is a 3" connection, so how are ya'll adapting your drain to feed into the campground connection?

Re: Question about venting gray water...

PostPosted: Tue Feb 07, 2017 10:54 am
by lrrowe
Before, I just set the hose into the pipe. But going forward, I am going to get one of those pressure fit adapters with a garden hose threaded connector on it.

Re: Question about venting gray water...

PostPosted: Tue Feb 07, 2017 2:47 pm
by McDave
I've said it before, and I'll say it again.... Hepvo, Hepvo, Hepvo. Saves space, waterless trap and air admittance valve.
Sanitary and no freezing issues. Check it out....Hepvo

McDave

Re: Question about venting gray water...

PostPosted: Tue Feb 07, 2017 3:02 pm
by lrrowe
Yes they are equally as functional for our needs.