What size fittings for tanks?

[Iceni John]

Next week I will order my four tanks from Ronco, but I've not yet decided what size fittings should be installed in them.   It seems that 3" is standard for the black tank's inlet and outlet, and 1.5" is common for the grey tank's outlet, but what sizes are best for the other fittings?   Some folk use 2" vents for their black and grey tanks, but Ronco says that 1.5" should be OK for vents.   What size inlets are typically used for fresh water and grey tanks  -  is 1" large enough?   I will use slip fittings for all the inlets in the top surfaces, so when the tanks are lifted up into position under the floor their inlets will automatically connect.

So, what sizes do folk here use for their tanks' inlets and outlets and vents?

John (yes, size does matter)

[Jerry32]

Yes 1 1/2 shud be fine for vents and I think 3/4 is ok for water as you not goin to deal with a high voluum. th fill a 1"  and 1/2 for vent to the fresh water tank

[Sean]

A couple of points.

First, remember that you can always use a reducer to make a larger fitting into a smaller one, but you can not go the other way around.

Second, it takes a long time for water to come out through small openings.  I recommend going to 3" for gray water unless your tank is smaller than 45 gallons.  Also, don't forget low-point drains on the fresh tanks.

1.5" is fine for most wet-vented waste stacks unless you have more than three fixtures. That's also fine for the black vent.

We added extra fittings on the other side of the tanks, plus 4" openings top-center in case we ever needed to clean them out.  PVC pipe plugs are cheap, so you can't have too many fittings, only too few.

We also added low and high 1/2" fittings on the two fresh tanks and the gray tank for sight glasses, which have come in handy many times.

HTH,

-Sean
http://OurOdyssey.BlogSpot.com

[Iceni John]

Sean,
Thanks for the good advice.   My two fresh tanks will be 110 gal each, the grey will be 115 gal, and the poo tank 65 gal, so I will go larger than smaller.   3" outlets for both grey and black sounds good, and maybe I'll have 1.5" inlets for fresh and grey tanks.   I like your idea of 1/2" fittings for sight glasses  -  probably more reliable than electronic level-sensing gizmos.

Once I get the tanks from Ronco the fun will start!   Vis, how to get 24" high tanks under a 12" space below the bodysides?   With hydraulic jacks, railroad ties and 4 x 4 timbers  -  I will jack each side of the bus up about one foot, push each tank in, lower the bus back down on the ground, then winch the tank up into position and secure it in place.   I won't be under the bus while it's up in the air, so hopefully death won't result if a jack loses its moral fiber.

Both the fresh water tanks will be inter-connected, with a fill entry on each side of the bus, so I can fill both tanks from either side.   I've already bought a bilge pump that will be used for transferring grey water to the black tank to help flush out "solids"  -  maybe I can aim its jet of grey water at the epicenter of any stalagmites that may be growing in the poo tank.   Ah, the joys of bus conversion, having to ponder these scatological and excremental issues!

Thanks, John

[Eric]

For some reason your use of "the Poo" has me humored beyond belief.....falling back into Childhood i guess....