Check your SMB fresh water valves

[1der]

Installed new tanks and PEX over the weekend in a friend's SMB RB50 E Series van. Got it all buttoned up and switched the water pump on. The water pump was burping which meant a leak some place. Traced it to the valve body from one of the original SMB valves used to manage the City water supply / tank fill lines. May have been caused by freezing but looked more like a failure.



We increased capacity from a single 10 gal to 25 gal (25 + 10) two tank solution with the ability to shut off the 10 gal tank if not needed. Added 3" O ring fill/clean-outs, water supply shut off to water pump , and very low water tank pickup for the water pump. The tanks extend about three inches beyond the couch frame but it was worth it. In a complete new build and locating the water pump, drains, etc. differently, the water tanks would have fit under the couch.

 

[1der]

Correction - Added a 15G Primary + 10G secondary tank for a total of 25G

 

[Stormy98]

Looks great. I have a slow (once a minute or so) pump activation I need to trace. I'll take an extra close look at the valves.

Those 3" fill/clean-outs look really convenient. What product is that? Tried a bunch of searches but couldn't locate anything similar.

 

[1der]

Re: 3" ports - I order them with the tanks with all the fittings spun welded at the same time.

 

[dbhost]

FWIW, I don't even have that much of my plumbing system left in the van. Only thing left is the city water hookup port and about 2" of pipe behind where they cut it off. Still need to find someone to fabricate a bracket as I lack the skill to do that myself... Installing a single 25 gallon fresh and 20 gallon gray tank...

 

[N147JK]

Those 3" fill/clean-outs look really convenient. What product is that? Tried a bunch of searches but couldn't locate anything similar.

Funny I'm just now putting in a similar port in my water tank. Primarily so I can fill the tank from the inside using portable water bags. Anyway I'm putting in a 4" marine-style "deck plate" for this. Many brands available, cost is about $10.

 

[1der]

@N147JK - those are handy and can be retrofitted to existing tanks with LOTS of care. The rubber o-ring on the mounting flange will not be enough for a watertight seal to the tank surface.

The sealing of the bolt-on ports is really quite difficult. Silicone definitely does not work and lap sealant and butyl are not something I would want near my domestic water.

I used something like form a gasket years ago when I did a retrofit but cannot remember which, maybe the hi-temp orange??

I did use SS washers and nylock nuts on the inside for the screws.

You will really like the ability to easily add water and inspect/clean the inside of the tank. I would recommend fabbing a tool to help open/close the port cap. It is a tremendous stress on the thumbs (arthritis later).

Consider, also, adding the elbow pick up to the water pump draw port.

 

[N147JK]

I used something like form a gasket years ago when I did a retrofit but cannot remember which, maybe the hi-temp orange??

Thank you 1der. Yes I found some food-grade silicone sheet to make gaskets. At 1/8" thick, I think it will work. My only grumble.. costs too much!