[kifo4173]

Hi all,

When I used to have a truck camper, it had a standard gravity dish fill like this one on Amazon: https://www.amazon.com/gp/product/B0735HHB84/ref=ox_sc_act_title_1?smid=A2PK7117F7TKMV&psc=1

I'd fill the tank until water started coming out of the vent port in the fill. This is a great solution IF it's away from any doors and has it's own hull intrusion on the side.

In my van, I'm planning on the same fill plate but mounted flush on a panel that sits vertically right at the opening of the rear doors. I remember filling the truck camper and there was always some water sloshing around-especially if the hose is turned on high. I don't want any of this water bouncing into the van.

How do I accomplish this water fill without water flying out? Should I instead use a threaded fill port and route the tank vent vertically first and then underneath?

How have others installed remote fill locations WITHIN the van and plumbed it so the vent can spew water without getting anything wet? I have a 30 gallon tank-needs to be a robust design as I'll likely leave the hose and relax for a few minutes while it fills.

Any creative solutions/ideas greatly appreciated!

Kipp

 

[Wowbagger]

The folks that did my conversion set my tank up with an overflow line that comes out of the tank, makes a loop over the top of the tank, then goes down and out the bottom of the van. That way, the overflow won't run unless the tank is full and will stop feeding as soon as the water level is below the top of tank. The city water fill was put on the aft left body panel with a line running to the tank, and an RV style fill point with check valve. There is a valve inside that allows the tank to fill from city water, so you just connect city water, turn off the pump, and open the valve to fill. If you don't shut it off, it will eventually start running out the overflow onto the ground under the van.

 

[GaryBIS]

Hi,

Maybe you could screw an extension onto the fill port to extend it out the door a bit? Just use the extension when filling and stow it when not.

Mine looks like this before the cover when on:

The tank extends a bit into the sliding door area and the fill port is in the open when the sliding door is open. I just unscrew the PVC plug and put the fill hose into the fill port and when it gets very close to full, I just pull the hose out quickly. It might spill a cup of water if I'm not fast enough, but has never been a problem.

Gary

 

[kifo4173]

The folks that did my conversion set my tank up with an overflow line that comes out of the tank, makes a loop over the top of the tank, then goes down and out the bottom of the van. That way, the overflow won't run unless the tank is full and will stop feeding as soon as the water level is below the top of tank. The city water fill was put on the aft left body panel with a line running to the tank, and an RV style fill point with check valve. There is a valve inside that allows the tank to fill from city water, so you just connect city water, turn off the pump, and open the valve to fill. If you don't shut it off, it will eventually start running out the overflow onto the ground under the van.

Hi,

Maybe you could screw an extension onto the fill port to extend it out the door a bit? Just use the extension when filling and stow it when not.

Gary

Thanks guys. These were my two ideas. Going with the vent under, I'm struggling to understand the physics of how it would work.

My tank only has fittings on one end, not on the top or bottom. Bottom fittings are drain and main water line, top fittings are fill 1 1/2" and vent 1/2".

Say my main water inlet is 8 inches above the 1 1/2" inlet. If my vent line runs from that upper adjacent 1/2" fitting over the tank but below the main water inlet vertical elevation and then runs straight down under the vehicle, the vent should run first right? There would theoretically be no way for water to back flow out of the fill unless the fill rate exceeded what the 3/8" vent line could handle. Is this correct?

In other words: water fills at a constant based on elevations, right? Anything I'm missing here? Sorry for the silly questions, I seem to be struggling with this concept :/. Thanks!

 

[RDinNHandAZ]

Fill rate should be unaffected by elevation. Yes the overflow will drain before the fill backs up 8” but it needs to run directly down from the overflow opening.
One thing I never liked about a similar tank I had in my last RV was the tank cannot really be emptied completely. Before emptying it I would put in a bit of Clorox to kill any algae or bacteria that might be left in the last 1/2 inch of water and then flush it before filling it next time. I swore if I had such a tank again it would have a bottom surface drain not a side drain.

 

[kifo4173]

Fill rate should be unaffected by elevation. Yes the overflow will drain before the fill backs up 8” but it needs to run directly down from the overflow opening.
One thing I never liked about a similar tank I had in my last RV was the tank cannot really be emptied completely. Before emptying it I would put in a bit of Clorox to kill any algae or bacteria that might be left in the last 1/2 inch of water and then flush it before filling it next time. I swore if I had such a tank again it would have a bottom surface drain not a side drain.

Why does the overflow only drain before the fill backs up IF it runs directly down from the overflow opening? Won't the overflow still drain first if I run it up over the tank so that the tank can fill completely, as long as the height of the overflow is less than the 8" elevation to the fill?

Yes-agreed re: the tank. I wrote a post about this earlier-something I'll just have to live with. I like this Trionic tank because of it's 3/8" thick walls and general quality, but agree re: the fitting location.

Another question for everyone: Does it matter if the tank fill is at the top or the bottom of the tank? I guess if it's at the bottom, my fill hose will always have water in it?

 

[GaryBIS]

Hi,

I think you have to be a little careful here.

The 3/8 vent line is not going to be able to handle very much flow, so if your flow rate into the filler exceeds what the vent line can handle, the inlet will overflow. Worse, if the inlet flow is high enough, it will pressurize the tank and these poly tanks with flat sides will not take very much pressure before they fail. I guess it depends on how you hook the filler hose to the inlet fitting and how fast you try to fill the tank.
A friend of mine blew out his brand new poly tank by overpressuring it when he filled it -- he got to try his poly welding skills

Gary

 

[kifo4173]

Hi,

I think you have to be a little careful here.

The 3/8 vent line is not going to be able to handle very much flow, so if your flow rate into the filler exceeds what the vent line can handle, the inlet will overflow. Worse, if the inlet flow is high enough, it will pressurize the tank and these poly tanks with flat sides will not take very much pressure before they fail. I guess it depends on how you hook the filler hose to the inlet fitting and how fast you try to fill the tank.
A friend of mine blew out his brand new poly tank by overpressuring it when he filled it -- he got to try his poly welding skills

Gary

Thanks Gary. You're pretty experienced-any creative ideas how to tackle this?

What if I put a 3/8" step down fitting on the hose inlet? The tank is almost 1/2" thick, I would think it would take a TON of pressure to fail.

The idea is I'd be standing right there and once I see a spurt of water from the under vehicle vent I'd immediately shut off the hose.

The only thing I really don't like about this design is that the fill hose will contain water until I use about 3-4 gallons of water inside. Not sure this is preventable, however.

 

[Wowbagger]

Here's a couple of pictures of my set up. In one, you see the City Water Fill (CWF) and the low point drain (LPT) on that line. The CWF is a standard RV fill that has a check valve, and that line is on the pressurized side of the system. The CWF check valve prevents water from being pumped out by the pump. Opening the LPT will allow the line to drain, and if the pump is on, will pump water out of the tank.

The second picture is of the tank and drain line. If you look closely, you can see the overflow coming out the side of the tank at the top, making the loop over the tank, then going down through the floor. The other line visible in the picture is the fill line - it goes into a valve just out of frame and into the tank. That line is also on the pressure side of the system, so that if I am on city water, it is pressurized by city pressure, else it is pressurized by the pump. Opening the valve will allow water from the pressure side into the tank - hence why I said I had to turn the pump off while filling, or it will just run water around the loop.

Due to the loop over the tank, the line will not siphon the tank down to the level of the overflow - only if the system is full above the level of the loop, or under pressure, will it run. In theory, you could put a line like this at any level into the tank so long as it is not under pressure - the water level in the line will match the level in the tank, and if it goes over then it will run out. However, if the line comes into the tank at a low level it won't serve as a vent line.

 

[GaryBIS]

Hi,

The fresh water tanks used in RVs typically won't take much pressure -- they are flat sided and typically less than a 1/4 inch thick. Sounds like yours might be thicker, but if its flat sided it still won't take much pressure.

I think as long as you fill it the way you describe -- that is, don't turn the hose on full blast, monitor it as you fill, and make sure there is a little clearance between the hose OD and the fill port ID that will allow a path for some overflow, I think you will be fine. Just don't do anything that will allow the full city water pressure to be applied to the tank.


Gary

 

[Winston]

Ours is a fairly simple arrangement employing 2 - 6 gallon jerry jugs under the sink. The fresh water tank is (only) filled through the city water connection (which we've now fitted with a 40psi regulator as many of the city water connections were 100psi). The filling process is manual and monitored. But having just 6 gallon tanks it doesn't take long to fill. Never tried pressurizing the tank (even at 40psi) - - we suspect Gary is correct, that the results wouldn't be pleasant.

Initially both fill and pump inlet hoses were loosely inserted through the top jerry jug spout (fresh water). The pump had no difficulty 'sucking' the water out. We later added a 'low point' outlet which now mostly gravity feeds the pump. Also added was a clear plastic tube up the outside of the tank to monitor tank 'fill' status.

As shown, we added a grey water low point outlet which goes straight down through the floor to a valve/hose (to the rear of the van) for draining.