Installing Tank Level Sensors - Waste and Water

[jviss]

How do you install a sensor in a plastic tank?

I have an under-v-berth water tank and a waste tank, both plastic, in which I'd like to install level sensors.

Need I install a flange, or can the plastic be threaded for a 1.5" NPT sensor head, as, for example, the WEMA SHST?

If you install a flange, I assume you need to get your hands on both sides of it, correct?

Thanks,

jv

 

[Peggie Hall HeadMistress]

What you really need is a system with senders that go on the OUTside of the tank. The Profile gauges are not only the best, but provide the best customer service anyone could ask for. Profile Tank Monitors

 

[jviss]

Thanks Peggy. I installed a Snake River Systems tank monitoring system on the C36; this one looks a lot like that. The truth is, at the moment I'd really prefer to go through the top of the tank, as in both cases of the bow water tank and the holding tank, access to the side to install would require removing the tanks. Plus, I want to use matching, "old school" gauges, not install a new gauge display. So, a standard, 240 to 30Ω sensor is what I want. The Wema waste tank sensor, SHS, seems pretty robust and it's popular. The SSS/SSL sensors for fuel and water likewise appear robust. My boat currently has the Wema fuel and water sensors. Some appear to screw into a 1.25" or 1.5" NPT flange, and others come with a flange that is either fixed, or has an internal thread.

I'm thinking I will have to install a flange. There's a clean-out port on both the waste and water tanks, that will make this possible.

 

[Justin_NSA]

SCAD aka Profile also sell an internal sensor if you must use one. They have a flange for it. I used on on my metal holding tank.

 

[Peggie Hall HeadMistress]

SCAD is actually a private label version of the Profile system...they both use the same sensor as the one that goes on the outside of the tank, but encased in a pvc tube so it never comes in contact with contents and therefore can't be clogged by the animal fats in waste as the internal sensors on WEMA and SeaLand do. And the ONLY way to clean it is to remove it and clean it by hand with a strong solution of detergent and water.
So you might want to consider sticking with WEMA for the water tank but going with the Solo version of the Profile (or SCAD for a higher price) for the waste tank.

 

[Patrick Lombard]

Installed years a go.

https://hunter.sailboatowners.com/mods.php?task=article&mid=25&aid=7325&mn=31_83-87

 

[jviss]

Installed years a go.

https://hunter.sailboatowners.com/mods.php?task=article&mid=25&aid=7325&mn=31_83-87

Thanks. You did a beautiful job! I installed an Accu-Gauge system on my Catalina 36; the panel looks a bit different, but the installation, etc., is the same. It was made by Snake River Systems.

I want the other type of sensors in the new boat because I don't want to have to get to the sides of the tanks, which would require removing them, and also, I want to use the same kind of gauges as are present for water tank 1, and the fuel tank, "standard" gauges that work with resistive senders.

Thanks,

jv

 

[LuckyPenny]

jv, I have not yet had to do this but its coming.
I took a quick look at http://www.wemausa.com/sensors/level-HoldingTank.shtml#.WdvLfWhSyHs
the SHS look like it comes with a split ring for mounting the included flange to your tank. The split ring allows you to put the +/- 3" ring through a smaller hole. To answer your last question in your original post every thing can be done through the hole the sensor will go through. Just a finger or two. Although I would back my finger up with a thread incase I slip. That way the ring will not fall to the bottom of the tank

 

[jviss]

I would back my finger up with a thread incase I slip

Thank you! Yes, I didn't pick up on the fact that the split ring allows mounting through the sensor hole, alone. And, yes, a thread through one of the holes is an excellent idea!