Freshwater Tank Capacity

[wp_owner]

My Work & Play 16UL supposedly has a 110 gallon freshwater tank (the "yellow" weight sticker says to count 916 lbs. towards cargo weight when the freshwater tank is full) . I've got an accurate water meter that I use to flush out my black (25 gal.) & grey tanks (38 gal.). When I try to fill my freshwater tank it starts spitting back air & water back through the small vent hole (located next to the main water input) when my water meter only reads 65 gallons.

Is it normal for it to spit that early? Should I continue to fill until I get water actually flowing out of the water input hole?

I've attached pics of my freshwater tank. For those of you who have the 110 gallon tank, does this tank in this picture look similar to yours?

Thanks!

[BarryD0706]

I would suggest that you measure it and then calculate the volume from that.

[Fire Instructor]

Fresh Water Capacity on an RV typically includes the water in your water heater. That said, 65 gallons is still low. On mine, the tank never get to more that 7/8 or so full, because the fill pipe and the vent are located on the side of the tank. and the plumbing runs almost completely horizantal (flat) to the fill port, so any more that I try to foce in, just runs right back out....

[TURBS]

Fill your tank sllllllooooooowly that's the key and your problem.
If you just turn your hose on and let it rip the air cannot escape faster than the water going in.
You can actually damage your tank by filling to fast.

Thank me later


Turbs

[wp_owner]

Originally Posted by BarryD0706

I would suggest that you measure it and then calculate the volume from that.

If it was actually just a case of length x width x height, I'd say this would be a good idea. However, did you happen to notice the 6 irregular-shaped, large "indents" on the bottom? Measuring all that and subtracting that volume would be a bit much--at least for me Thanks, though!

[wp_owner]

Originally Posted by f1100turbo

Fill your tank sllllllooooooowly that's the key and your problem.
If you just turn your hose on and let it rip the air cannot escape faster than the water going in.
You can actually damage your tank by filling to fast.

Thank me later


Turbs

Good point. However, I didn't just let 'er rip. I turned the flow rate down quite a bit when it started spitting air and water. That didn't help, so I stopped for the very reason you mentioned--I didn't want to risk damaging the tank. I looked at the water level (tank is somewhat translucent) and it appears the water level was just below the fill-hose which connects to the tank. The small vent is in the same area. It appears to me the tank is about 80% full with approx. 60 gallons of water. I'm guessing it's very possible there' nothing wrong with the tank and a freshwater tank with less capacity than advertised was installed inadvertently.

[TURBS]

100 gallon tank would be approximately 72"x18"x19"
If that helps.....
Turbs

[garbonz]

I think that tank is nowhere near 18 or 19 deep, not even considering the indents...

[TURBS]

This might help finding the actual size to gallonage.
http://www.plastic-mart.com/category...FWpk7AodKnQAnQ

[Healeyman]

Measure the tank and multiply length times width times height and multiply times .004329. THAT calculation will give you the gallon capacity of the tank.

1 cu.in. = .004329 gallons. For example, a tank 72" X 72" x 4" is about 90 gallons.

If you are really serious about it, measure and subtract the indents or just SWAG it.

It would also probably help to fill it if you figured out where the vent tube connects to the top of the tank and roll THAT side of the unit up onto 2 x 4s or something else to raise it a bit and get the inevitable bubble to the vent.

Also, a gallon of water = 8 pounds.

Tim

[wp_owner]

I was really hoping someone would be able to look at my pics and say, hey, that's the xx gallon tank and save me the hassle of crawling underneath my toy hauler after a hard rain. Well, guess not . . .

So, very relunctantly crawled underneath my toy hauler with my tape measure and did some rough, quick measurements (the suggestion BarryD0706 first made and which I balked at, sorry). The tank has 3 "sections". The front and rear sections are the same size. The middle section is the large section that drops down much lower than the front and rear sections and also has the "indents". "Swagged" the measurements for the wierd-shaped "indents" (as Healeyman suggested) and subtracted this volume from the large middle section.

I came up with 76 gallons. I'm guessing the position of the input hose and vent (on the side, down about 1 - 1 1/2" inches from the top of the tank) probably limits the tank to about 80% of its volume. So, 80% of 76 gallons is 61 gallons.

These figures concur with my realworld capacity of 60-65 gallons. Mystery solved. If the 110 gallon capacity was a real priority, I'd be pissed. But, I don't dry camp that much so I'm ok with the lower capcity. My black (25 gal.) tank typically fills up before my freshwater tank empties (kitchen sink is plumbed to the black tank). Even if I had the 110 gallons I'd still have to pack up and leave

Thanks to everyone!

[VinceU]

Originally Posted by wp_owner

I was really hoping someone would be able to look at my pics and say, hey, that's the xx gallon tank and save me the hassle of crawling underneath my toy hauler after a hard rain. Well, guess not . . .

So, very relunctantly crawled underneath my toy hauler with my tape measure and did some rough, quick measurements (the suggestion BarryD0706 first made and which I balked at, sorry). The tank has 3 "sections". The front and rear sections are the same size. The middle section is the large section that drops down much lower than the front and rear sections and also has the "indents". "Swagged" the measurements for the wierd-shaped "indents" (as Healeyman suggested) and subtracted this volume from the large middle section.

I came up with 76 gallons. I'm guessing the position of the input hose and vent (on the side, down about 1 - 1 1/2" inches from the top of the tank) probably limits the tank to about 80% of its volume. So, 80% of 76 gallons is 61 gallons.

These figures concur with my realworld capacity of 60-65 gallons. Mystery solved. If the 110 gallon capacity was a real priority, I'd be pissed. But, I don't dry camp that much so I'm ok with the lower capcity. My black (25 gal.) tank typically fills up before my freshwater tank empties (kitchen sink is plumbed to the black tank). Even if I had the 110 gallons I'd still have to pack up and leave

Thanks to everyone!

Interesting perspective, tanks all have priority, on the other hand you knew at the outset, that tank could not hold 100-1 gal. milk jugs right?

[garbonz]

Wonder why they (forest river) are so far off? They should know the tank capacity by the size they ordered. Snot rocket science

[wp_owner]

Originally Posted by VinceU

Interesting perspective, tanks all have priority, on the other hand you knew at the outset, that tank could not hold 100-1 gal. milk jugs right?

Nope, didn't know it wouldn't hold 110 gallons. I don't think most places verify that kind of stuff during a PDI. I plan on giving Forest River a call to see what the capacity is supposed to be for my unit. FWIW, the freshwater tank I have right now takes up a *lot* of space above the axles. Not sure there's much room for a larger tank.

[Pipeman]

I had a 110 gallon US tank on my TH. When it started to spit out the vent tube, I shut off the water for a few seconds until the tank burped and then turned the water back on at a lower rate. It usually filled after that for quite a while. I do the same for our present 5er, which is supposed to hold 60 gallons. Our black tank is supposed to hold 40 gallons but I often think it's smaller than that. One of these days I will do an accurate fill on both.