gray tank construction 22FQS

[PaulStafford]

I'm planning on installing an electronic pressure sensor using a 3/4" uni-seal to provide a usable opening at the bottom of the (50 gal) tank. This requires drilling a 1.25" hole in the bottom.

My only concern is that inside the tank there might be stiffening ribs, and with that large a diameter, the odds go up of hitting one. To my surprise in inspecting the tank ahead of the operation, I discovered its black - so no chance at all of determining anything (unlike a more translucent tank.) After watching a video on spin roto molding, I"m thinking this is not a worry.

Anyone done this?

Any idea if the inside of the tank is uniform or not?

And - I"m not terribly concerned, but wall thickness for Uni-seals can't exceed 1/2". I'd be shocked (it would make it very heavy), but anything's possible. Anyone know that?


Thanks in advance

[ALLOY]

Originally Posted by PaulStafford

I'm planning on installing an electronic pressure sensor using a 3/4" uni-seal to provide a usable opening at the bottom of the (50 gal) tank. This requires drilling a 1.25" hole in the bottom.

My only concern is that inside the tank there might be stiffening ribs, and with that large a diameter, the odds go up of hitting one. To my surprise in inspecting the tank ahead of the operation, I discovered its black - so no chance at all of determining anything (unlike a more translucent tank.) After watching a video on spin roto molding, I"m thinking this is not a worry.

Anyone done this?

Any idea if the inside of the tank is uniform or not?

And - I"m not terribly concerned, but wall thickness for Uni-seals can't exceed 1/2". I'd be shocked (it would make it very heavy), but anything's possible. Anyone know that?


Thanks in advance

You can't get reinforcing ribs inside a roto mold tank. The along the corner will be thicker than the body of the tank.

Why are you putting a pressure sensor into a tank that's not meant to hold pressure?

Spin welding takes a little practice. I do it with a 1hp router.

[PaulStafford]

Thanks, no ribs is what I suspected.

the pressure sensor will give a signal proportional to how full it is. Max pressure will be about .8 psi. So you need a sensitive sensor.

This works very well- I've already installed and calibrated one in the fresh water tank. The signal goes to a Victron Tank 140, which conditions the signal so it can be displayed on the Cerbo GX/Touch 50. Here's a shot of the display with the fresh water tank level displayed.

[PaulStafford]

Well, surprise, surprise. I also wrote to ORV service mgr. Here's his reply. I guess I DO have to worry about hitting a stiffening rib.

[MtCamper]

Seems like a lot of effort to go thru to get info of relatively little importance. Then again it's your mod, if it makes you happy go for it.

[PaulStafford]

MT Camper- If I'm honest, modding the RV has turned into an obsession.


And a follow up in case anyone's interested- Rick wrote back after his first response- turns out only the fresh water tank has ribs, the gray and black do not.

[ALLOY]

Originally Posted by PaulStafford

MT Camper- If I'm honest, modding the RV has turned into an obsession.


And a follow up in case anyone's interested- Rick wrote back after his first response- turns out only the fresh water tank has ribs, the gray and black do not.

Ribs in a black/grey tank would prevent stuff from draining out of the tank.


On rotomold the ribs are depressions that can be seen from outside

[ALLOY]

Originally Posted by PaulStafford

Thanks, no ribs is what I suspected.

the pressure sensor will give a signal proportional to how full it is. Max pressure will be about .8 psi. So you need a sensitive sensor.

This works very well- I've already installed and calibrated one in the fresh water tank. The signal goes to a Victron Tank 140, which conditions the signal so it can be displayed on the Cerbo GX/Touch 50. Here's a shot of the display with the fresh water tank level displayed.

It won't be affected by the stuff in the tank?


I'd check to see if there's an external sender with the correct output to work with the Cerbo.

[Dave Pelletier]

Originally Posted by ALLOY

Ribs in a black/grey tank would prevent stuff from draining out of the tank.


On rotomold the ribs are depressions that can be seen from outside

yep.

[BLK-9]

What are the "ribs" you are referring too here?

[Vintage465]

I think you plan will work. This is what I do....I have 60 gallons of fresh water. When I'm nearly out of water, I'm nearly 2/3 full on either or both tanks. The factory sensors are really a "suggestion" of what could be.............