> From:    Dave Vickery <davevickery@HOTMAIL.COM>
> Date:    Thu, 31 May 2007 01:45:30 +0000
>
> But, I like the idea of using 4" PVC tubing cut to the proper length
> and then mounted between the frame rails.

I like this idea too.  You might even be able to use smaller pipe and/or
L, T, and maybe even X connectors to fit more pipe around the existing
equipment under the van.  A little Googling shows that for PVC Schedule
40 drain pipe, the nominal size is the inside diameter.  This gives:

Nominal  1 foot     Length for  0.5 m   Length for
size     length     1 gallon    length  5 liters
4"       0.653 gal  18.4"       4.05 l  0.617 m
3"       0.367 gal  32.7"       2.28 l  1.10 m
2"       0.163 gal  73.5"       1.01 l  2.47 m

(if the table looks bad, use a fixed width font such as Courier)

Note that this is just the pipe itself - the end caps are usually domed
and give you a small amount of additional volume.

> Since it's PVC all you have to do is use PVC glue to tap in whatever
> fill/empty connections you want.

One thing you might have to have is a vent connection.  Not all the way
up to the roof like in a house - just a hole on the top of the "tank"
for the air to get out as you pour more water in.  This could be a
separate fitting, or it could be as simple as using, say, a 1.5" ID
fitting for the inlet but just shoving a garden hose in it, allowing the
extra air to escape around the hose.

As with any grey water tank, the best way to avoid a funky-smelling tank
is to get rid of the water as soon as is practical.  It helps a little
to squirt some hand dishwashing detergent (Dawn, Joy, or similar) into
the tank.

Matt Roberds