Fresh water solenoid

[Scott'n'Wendy]

I'm revisiting the idea of a solenoid valve on the fresh water system. I have a couple concerns that maybe those of you that have done this mod could address. First, is the weight of the solenoid valve itself. Will it need to be fastened to the wall or floor? I have visions of a solenoid valve bouncing up and down as you go down the road stressing the pex connections - legitimate concern?
The other is the voltage chosen. 12vdc draws slightly better than 1 amp all the time. That is a reasonably large parasitic draw. They are less than 1/2 the cost of a 120vac unit. However, 120v solenoid only draws 0.1 amp or so. But..when you are at a fill station to fill the fresh tank - what do you do?
So what voltage did you go with and why?

[TedS]

Find a latching solenoid valve that does not draw current when latched open.

[Scott'n'Wendy]

Find a latching solenoid valve that does not draw current when latched open.

Didn't know water valves like that existed...I'll check around

[Scott'n'Wendy]

Cate&Rob
What voltage solenoid do you have? Pros, cons about having the fresh water solenoid?

[Jkwilson]

Look for a motorized ball valve.

Ihave this one https://www.amazon.com/dp/B06XCZ35NB...v_lig_dp_it_im

It’s full port and uses no power except when switching.

I have it installed in mine, but don’t have all the switches installed because I’m not exactly sure yet how I want it to work I’m thinking I want a timer so after so long without using water, the pump and water heater are disabled, and the valve closes. But sometimes that’s going to shut down when I don’t want it to, so maybe I need a motion detector to delay the shutdown too. I’m thinking an open switch in the kitchen and bath, and open and close available in the convenience panel and water panel

[TedS]

What is this valve to do in the water system? Where in the water system?

[Scott'n'Wendy]

Jkwilson I think I will go with the motorized ball instead of a solenoid. But for your plans maybe you need a little Keyence PLC to run all the conditions and interlocks you are thinking of. lol
They have some neat stuff. I have programmed a few of their plc's. Easy and straightforward. Being an engineer I KNOW you really would like to add a plc to your trailer...lol
https://www.keyence.com/products/con...ng-block-type/

TedS Rob, Cate&Rob has a plumbing pdf on the site from a presentation at the rally. In it you see a valve on the inlet of the fresh water.
I started thinking about it again recently after seeing the expanded fresh water tank that John posted up a couple days ago. I see it would be valuable in being able to remotely switch off the city water supply overnight. Thinking plumbing issues when you are asleep...when else would they happen?

[Cate&Rob]

Scott'n'Wendy I use the motorized ball valve that Jkwilson links in post 5. It draws no power in either the open or closed position. Senses 12V to stay open and 0V to close. I have mine wired to the electric side of the water heater . . . since electric water heating usually goes with a campground water connection. When we leave the trailer we always shut off the water heater . . . which shuts off the ball valve. Thinking about that expanded tank . . . maybe I will put another one of these valves on the line to the tank . . . just have to figure out the open/close logic.

Rob

[Scott'n'Wendy]

Thinking about that expanded tank . . . maybe I will put another one of these valves on the line to the tank . . . just have to figure out the open/close logic.

Rob

Do you think if the check valve failed and water flowed to the tank...and the tank had no restrictions on the o-flow...incoming water could still over pressurize the tank? I'm thinking yes...what say you?

[Scott'n'Wendy]

Cate&Rob Jkwilson

Regarding the valves you bought. Is there any advantage/disadvantage to brass vs stainless?

[TedS]

Do you think if the check valve failed and water flowed to the tank...and the tank had no restrictions on the o-flow...incoming water could still over pressurize the tank? I'm thinking yes...what say you?

The pressure drop through the over flow would not be high enough to cause a tank to fail.

Many of us watch for flow out the vent to signal a full tank, the sensors being what they are.

[Scott'n'Wendy]

Many of us watch for flow out the vent to signal a full tank, the sensors being what they are.

Oh I do that too. But I shut the water off as soon as I see it coming out the o-flow. Was just wondering if you were not there, city water was on and the check valve failed...could it over pressure the tank?

I know...perfect storm...and why did i leave the water on....

[TedS]

Chart for pressure drop per 100 ft. Water flow will be around 3 to 5 gpm. Vent tube could be 1 to 10 ft. Pressure drop could be 0.01 to 0.1 psi.

[Jkwilson]

Cate&Rob Jkwilson

Regarding the valves you bought. Is there any advantage/disadvantage to brass vs stainless?

Brass is cheaper, stainless lasts longer. If the water is fairly benign, the advantage of stainless is minimized, but with an RV you get to experience all kinds of water.

[Cate&Rob]

Do you think if the check valve failed and water flowed to the tank...and the tank had no restrictions on the o-flow...incoming water could still over pressurize the tank? I'm thinking yes...what say you?

The water pump has a check valve on each chamber. If one of these were to leak, this would be a very low flow back to the tank with city water supply. An open overflow should certainly be able to drain this amount of water without expanding the tank.

My Kantleak water system (early GD products) has a "tank access" valve. If this were to be left open, it would provide high flow to the tank . . . although, through a 1/2" line whereas the overflow is 3/4". The overflow should still be sufficient.

The more that I think about this . . . the more I am certain . . . that I would never put a valve of any kind on the tank overflow. If I needed to travel with a full water tank (which I don't) I would work out a high vent system.

Rob