location of "P-traps"

[buddy110]

Does anyone know where there are p-traps located in our coaches? I have a straight dump to the toilet (y floor plan)three sinks, kitchen and double bay in the bathroom. Maybe there is one under the washing machine and perhaps under the shower, but there are none at all in the cabinet bays under the sinks.

Where if at all are they located? Perhaps there is one master directly above the gray tank?

[Isaac-1]

There may not be any, you may have Hepvo valves instead

[buddy110]

Originally Posted by Isaac-1

There may not be any, you may have Hepvo valves instead

Yes, I argued that with a Facebook "master plumber" but he was unconvinced

[Old-Biscuit]

Hepvo valves are 'p' traps just waterless (mechanical vs vapor barrier)

They can be installed vertically on sink tailpipe or horizontal on sink drain lines (which can be tucked several feet away from sinks)
Washer and shower would also have some type of vapor barrier......water or waterless

*Toilet does not use a 'p' trap.......water in bowl is the vapor barrier
**Macerator toilets have a Loop in pump discharge line

[brobox]

The newer coaches have waterless p traps in the drain lines of each sink

[buddy110]

Thanks everyone. That's what I thought as well. The subject came up on a FB page concerning leaving a tank valve open. I suggested never to leave the black open, but if necessary, leaving the gray open is Ok providing you form a P-trap in the macerator hose. A master plumber jumped all over me about that. He's convinced no bugs can crawl into the coach because ALL coaches have P-traps.

Now if I understand a hepvo valve correctly, since there is no standing water it would not stop a potential sewer creature from reaching your sink bowl. Is this correct?

[Poppedclams]

How about 15 and lower. I spotted 2 in bathroom sinks

[brobox]

Originally Posted by Poppedclams

How about 15 and lower. I spotted 2 in bathroom sinks

Classics have "old style" regular P traps. Easy to remove and clean.

[Old-Biscuit]

Hepvo waterless traps......internal duckbill that opens to allow flow out then close so odors do not come backup from grey tank....mechanical vapor barrier

https://hepvo.com/hepvo-waterless-valve/






Side note:
If waste tank dump valves are left open sewer flies CAN come up thru sewer hose/valve and set up house inside the waste tank BUT not thru 'traps' and crawl out of sink/shower
Can come up thru standard gravity dump RV toilet when flushing

[Gary.Jones]

Thanks guys...

This is a topic I have never seen discussed before and also a topic that I know absolutely nothing about. So this whole thread will be copied and saved in my coach repairs directory on the computer that goes into the coach.

Also, it would appear that the duckbill will prevent any creepy crawlers from coming up through the sewer lines.... !

Thanks for the lesson on a previously unknown topic. !

Gary

[buddy110]

Originally Posted by Gary.Jones

Thanks guys...

This is a topic I have never seen discussed before and also a topic that I know absolutely nothing about. So this whole thread will be copied and saved in my coach repairs directory on the computer that goes into the coach.

Also, it would appear that the duckbill will prevent any creepy crawlers from coming up through the sewer lines.... !

Thanks for the lesson on a previously unknown topic. !

Gary

I would not count on that. Those buggers can squeeze through very small areas. I choose to stop them at the source. Either keep the gates closed until full or form a P-trap in the macerator hose

[Poppedclams]

Wondering if shower has p trap ??

[Gary.Jones]

Bruce

I may be naïve, but I have assumed that there are very few critters that can survive for long in my black tank. I don't think that I have ever even had an ant that come up through the black tank or piping. Now, I have the dump system and value turned off all the time (I never just leave the valves open) so I try to prevent the entrance of any critters by closing off the system fully all the time except when I "dump tanks" and then I immediately shut everything off again.

Hasn't been a problem.

Gary

[voltdoc]

Originally Posted by Poppedclams

How about 15 and lower. I spotted 2 in bathroom sinks

My '17 has P traps all around.

https://photos.app.goo.gl/opRVEvfVGDYkR6TcA