Combined Gray and Black Water?

[markdoane]

Malcolm,
I'm adding a one-way valve on the shower drain. I don't know if or how well it will work. It's a common check valve used on irrigation pumps. See the red and blue plastic thing low right center of the picture.
If it doesn't work, I'll take it out. Cost is $10.

[malconium]

I would like to add a similar valve to my shower and see what happens. Am I going to be able to find this at a local hardware or plumbing store?

Malcolm

[markdoane]

Originally Posted by malconium

I would like to add a similar valve to my shower and see what happens. Am I going to be able to find this at a local hardware or plumbing store?

Malcolm

Yeah. Home Depot has them, near the sump pump section. Also check "Fernco" brand rubber tees and elbows in the same area. Better for plumbing connections I think because they soak up a lot of vibration.

[malconium]

Don,

Thanks for the tip about flexible fittings (and where to find the check valve). That seems like a great idea for the type of application we are working on.

Malcolm

[uwe]

Originally Posted by malconium

Uwe,
Actually the Inca Plastics site does make custom tanks and at reasonable prices from what I can tell so far.

http://www.incaplastics.com/rvtanks.htm

They want a fax of a drawing or an emailed request for quote if the shape is a simple one.

Malcolm

They will after making a mold for each tank you need, and if you buy in quantity.

[AirConditioner]

For special applications you might consider a flexible tank. I've used these for years on sail and powerboats and they are great for fillling in tight, irregular spaces. You can always use two or more for added capacity and weight distribution. They aren't cheap, but they will do the job.

http://www.imtra.com/index.cfm?fa=pr...productId=1680

[malconium]

AirConditioner,

I am willing to consider using flexible tanks if it makes sense. I did find a less expensive source for them at the following location that someone else in these forums pointed to:
http://www.foreandaftmarine.com/VTWASTETANKS.htm

It seemed to me that the marine style installations typically have a macerator pump on the input side of the flexible tanks. Also the typical fittings on the flex tanks seem to be no bigger than 1-1/2". I don't know about using a marine style toilet with a macerator pump. I would guess they would tend to be a bit noisy for middle of the night use.

Uwe,

You are right about Inca. I found out the same when I asked for a quote for a specific size. I did find another site that claims they can make custom sizes by welding flat stock together. I have not requested a quote from them but you might want to check them out:

http://all-rite.com/

I think that I will check with them about something and I will post what I find out here in this thread. Otherwise I have almost decided to use a flat bottomed water holding tank which I would mount with a slight slope.

Malcolm

[malconium]

I just called the customer service number at All-Rite (800-642-9988) and was given an initial quote over the phone. I was told that they would want me to fax a drawing with the exact details for final confirmation. They make welded polyethelene tanks out of flat sheets. I asked about a tank with the following aproximate dimensions:

20" wide
54" long
9" tall

I asked for a slope from one end to the other and a 3" fitting on the side at the down-hill end. This overall size would be around 40 gallons by the way.

I was told that a tank of that size and description would cost $366.77. The manufacturing lead time would be about 48 hours. Shipping costs from California to Oregon would be about $25. While that price is a bit higher than what I have been seeing for stock items it does not sound too bad for a completely custom product. For perspective I have found completely rectangular water tanks with no fittings in that general size for around $200 or so. RV Parts Outlet has one of that size in stock at their warehouse for $222.00 (no shipping charge since they are local for me). I have been told that water tanks are typically not as thick as holding tanks though. I have seen stock 40 gal holding tanks of the same aproximate capacity for in the range of $175 to $240.

My problem is that I have been having trouble finding a stock holding tank of about 40 gallons that will fit between the frame cross-members without any modification (to the cross-members). I figure the max width I can fit in is 23-1/2" wide. I want to put the tank in the cavity just behind my rear axle. That space is still between the wheel wells so I need to have the outlet be on the side of the tank facing toward the rear of my trailer. I have found combinations that come close but not close enough. Does anyone know of any sources that have not already been mentioned in this thread?

Malcolm

[Armorhotdog]

have you considered lashing in a pair of Blue Boys? I have a 22 gal that is relatively small and I have often though that a pair in parallel would be a great permanent installation. Glenn Oregon City

[JohnG]

Malcolm,

Just a thought and you may have it covered, but if you did I missed it above. I know that UWE has stressed the ventalation for the tank, but can the odors from the combined tank make their way up into the trailer through the shower?
I certainly know that I would hate to open my door planning to relax only to find a very unpleasant odor hitting me in the face. That and swatting the flys away...........

[uwe]

A shower must have a trap, just like a sink or toilet at home.( or in the trailer)
The trap holds water, which seals the drain from odors.