How I got 42 gallons from a 30 or 36 gallon water tank

Riverbug

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Been doing lots of work on the new camper this spring. Yesterday I did another project that turned out pretty interesting. I'm not a blogger, vlogger, or whatever so I didn't think to take any pictures to show exactly what I did, which I wish now I had done. Here's the synopsis...The fresh water tank sags once it has been filled, and it doesn't pop back up as it empties. The exit fitting that connects the water pump to the tank is an inch or so from the bottom at the end of the tank. As seen in this pic that I did take days prior to thinking up this project...
View attachment 47102

My paperwork says I have a 36 gallon tank. I've seen a post where someone said that number includes whatever is in the water heater (so it's actually a 30 gallon tank + 6 gallons in the water heater); I cannot confirm whether that is true but it makes this a more interesting debate as follows. After completing this project, I used a flow meter to fill the tank, which was empty (to the point of using the dump valve anyway). The meter indicated that I put in 35 gallons at the point it overflowed. I then used the exterior hose and onboard 12V pump to pump the water out until it ran empty (this took a long time with the lower flow of the pump and coil hose). The flow meter indicated I pumped 42 gallons out of the tank.

So, what was the project? I needed a way to get the water out of the tank the was below the exit fitting (elbow). I took the idea from our pressure sprayer where the hose and hand sprayer are connected to the tank at the top, but if you unscrew that hose connector from the tank, you find a "straw" that connects to the fitting on the inside and runs down to the bottom of the tank. as long as the "straw" has a good seal to the fitting, and therefore the hose/hand sprayer, it will suck the fluid out until it is empty.

I just used two sizes of clear tubing. The first was the right size to fit tight to the inside of the black elbow fitting pressed in tightly and cut to the length of the threaded fitting. The second tube was smaller and fit tightly inside of the first piece of tubing, but this piece was cut to 26" long. I straightened it buy holding one end in the bench vise and the other hung straight down with a c-clamp (for weight). Then I used a heat gun to get it hot the entire length, and let it cool for a while just hanging there. When done it holds its shape and does not curl up. When I stuck it through the hole in the water tank and screwed the elbow in (wrapped with teflon tape), it laid straight to approximately the center of the tank at its lowest point. Note: the reason for the two sizes of tubing is due to the water tank itself. The fitting screws in until it is stopped by a flange in the tank. Therefore, the hole where the water comes out is smaller than the hole where the elbow screws in, thus the smaller tube inside the larger tube.

That's a long-winded explanation but hope that helps anyone who might be ambitious enough to do something similar or find an easier, better way to do it.
 
Been doing lots of work on the new camper this spring. Yesterday I did another project that turned out pretty interesting. I'm not a blogger, vlogger, or whatever so I didn't think to take any pictures to show exactly what I did, which I wish now I had done. Here's the synopsis...The fresh water tank sags once it has been filled, and it doesn't pop back up as it empties. The exit fitting that connects the water pump to the tank is an inch or so from the bottom at the end of the tank. As seen in this pic that I did take days prior to thinking up this project...
View attachment 47102

My paperwork says I have a 36 gallon tank. I've seen a post where someone said that number includes whatever is in the water heater (so it's actually a 30 gallon tank + 6 gallons in the water heater); I cannot confirm whether that is true but it makes this a more interesting debate as follows. After completing this project, I used a flow meter to fill the tank, which was empty (to the point of using the dump valve anyway). The meter indicated that I put in 35 gallons at the point it overflowed. I then used the exterior hose and onboard 12V pump to pump the water out until it ran empty (this took a long time with the lower flow of the pump and coil hose). The flow meter indicated I pumped 42 gallons out of the tank.

So, what was the project? I needed a way to get the water out of the tank the was below the exit fitting (elbow). I took the idea from our pressure sprayer where the hose and hand sprayer are connected to the tank at the top, but if you unscrew that hose connector from the tank, you find a "straw" that connects to the fitting on the inside and runs down to the bottom of the tank. as long as the "straw" has a good seal to the fitting, and therefore the hose/hand sprayer, it will suck the fluid out until it is empty.

I just used two sizes of clear tubing. The first was the right size to fit tight to the inside of the black elbow fitting pressed in tightly and cut to the length of the threaded fitting. The second tube was smaller and fit tightly inside of the first piece of tubing, but this piece was cut to 26" long. I straightened it buy holding one end in the bench vise and the other hung straight down with a c-clamp (for weight). Then I used a heat gun to get it hot the entire length, and let it cool for a while just hanging there. When done it holds its shape and does not curl up. When I stuck it through the hole in the water tank and screwed the elbow in (wrapped with teflon tape), it laid straight to approximately the center of the tank at its lowest point. Note: the reason for the two sizes of tubing is due to the water tank itself. The fitting screws in until it is stopped by a flange in the tank. Therefore, the hole where the water comes out is smaller than the hole where the elbow screws in, thus the smaller tube inside the larger tube.

That's a long-winded explanation but hope that helps anyone who might be ambitious enough to do something similar or find an easier, better way to do it.

Thanks for sharing, any of us who camp off-grid will want to get as much water as we can out of the tanks. Like you, I also wish you had some photos to share. It would make your solution a lot easier to understand.
 
Thanks for sharing, any of us who camp off-grid will want to get as much water as we can out of the tanks. Like you, I also wish you had some photos to share. It would make your solution a lot easier to understand.

Well, this morning I decided to order the SeeLevel system so before I install that and button up the underbelly for good, I'll try to take that elbow out and document with pictures/details and update the original post if it will still let me edit when I'm done.
 
Well, this morning I decided to order the SeeLevel system so before I install that and button up the underbelly for good, I'll try to take that elbow out and document with pictures/details and update the original post if it will still let me edit when I'm done.

If you can't edit the original post, just add a reply with the new material.
 

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