Where to connect sink and shower drains to grey tank?

[mervifwdc]

Hi folks,

I'm in the process of fitting a grey tank to the underside of my camper, and I'm wondering if I should connect the shower and sink to the top of the tank, or the bottom of it? Top I think, but some "standard" tanks seem to have inlets all on the bottom...

Do folks fit U bends under the sinks (to keep the smells away...)?

I plan to connect them using T connections and manual valves so I can bypass the tank when I'm somewhere appropriate, or in extreme cold for example.

I dont intend for the tank to be full for very long, 2 days max. it's only 45 litres (10 gals approx).

Any tips most welcome!
Merv.

 

[chasespeed]

First, I would certainly use a trap... the trap is, just as you said, to keep "smells" where they belong... but, that is also methane. Put the "T" below the trap, see if you can find a wye valve, and put that right by the tank, where the shower and sink will enter, then, you only have to mess with one valve.

Second, drain into the top of the tank. The fittings on the bottom, are for the drain....

Chase

 

[doug720]

As to the traps, yes use them! But you will also need stoppers or covers for the drains when the camper moves. The movement causes the traps to loose their water seal and the smell comes right in! I'm a long time motor home owner...Trust me!

Doug

 

[mervifwdc]

Thanks folks!
Doug - great tip!

Would a manual valve under the sink, just between the trap and the sink be overkill? - Right now it would be easy to do.... Not so easy under the shower, but I guess I could put one underneath for that...

Merv.

 

[wjeeper]

Sounds like everybody has got it all answered for you. One thing I heard about the other day was a "waterless P-trap". It supposidly solves the problem of the water sloshing out and the smell coming through while on the move. It also looks to be pretty compact.

http://drainmaster.com/hepvo.html

I have absolutely no experience or need for the product so I cant offer any help in that department, but if I was hooking up an RV sewer/ gray water system I would look into it.

 

[mervifwdc]

That looks like a pretty neat idea! I think it's well worth trying. I'll give it a go and report back. Luckily, I've easy access to the plumbing areas, so it's not a big deal if I have to change to a more conventional system.

Thanks!
Merv.

 

[zidaro]

Ive been running a HEPVO valve in my Northstar for over a year and love it. It took forever, but they finally made it to the states. Been in use in Euro. for years.
Will never install another P trap on a drain again. Its a simple one way flutter valve and it works, best is that it has no contained water to freeze in winter months. One less thing to worry about.

 

[mervifwdc]

I tried my local hardware store, and they never heard of them. Then we looked in their catalog from the company "wavin" who make them, and found 2 pages at the back with the part numbers.

I've now got 2 fitted. one from the sink, and one from the shower. I ran the shower, no bubbles, no delays, no glugs, so far so good. The shower one is mounted horizontally, and the sink almost vertical.

I went for the 40mm version, but I think that was a bit silly as the shower and sink drains are closer to 20mm. I had to jury-rig connections to go onto them, but I did so in a way that I can disconnect the new pipes, and re-connect the direct drain pipes very easily in case I need to.

It was a lot of work for a very little tank!

but I thought I'd show a photo with the connectors for the hepvo pipe installed on the top (3 holes - 2 inlets and a breather. I decided to do all the connectors the same, that way I'm carrying a spare with me....)

Thanks for all the help!
Merv.