Solenoid valve for saltwater?

[Levinson]

I'm looking for a small electrically operated valve that I can run my tank water through for a DIY project.
It seems like plastic solenoid valves are the most common ones available, but I'm not sure if these would have any metal bits exposed to the water inside or be safe to run my tank water through. It will just be running the tank water inside and not submerged. It doesn't have to handle much pressure or flow.
I'm currently looking at products like this https://www.aliexpress.com/item/1005005253916656.html .
This product would be ok for my purpose if it is reef safe inside. Do you know if these would be safe to use?
Also, I'm looking at the 'normally open' type and if my understanding is correct, the valve is normally open but closes when power is on and opens back up when the power is down again. Is this correct?

 

[Levinson]

The DIY project may or may not need the electrically operated valve as I'm still in the planning stage but I wanted to check if the option was available for me.

 

[Tavero]

I'm looking for a small electrically operated valve that I can run my tank water through for a DIY project.
It seems like plastic solenoid valves are the most common ones available, but I'm not sure if these would have any metal bits exposed to the water inside or be safe to run my tank water through. It will just be running the tank water inside and not submerged. It doesn't have to handle much pressure or flow.
I'm currently looking at products like this https://www.aliexpress.com/item/1005005253916656.html .
This product would be ok for my purpose if it is reef safe inside. Do you know if these would be safe to use?
Also, I'm looking at the 'normally open' type and if my understanding is correct, the valve is normally open but closes when power is on and opens back up when the power is down again. Is this correct?

As far as I remember none of these have exposed metal parts. They do however have a rather small valve hole which will get clogged fast if you transfer biological active water through it. The small size also limits flow.

 

[Levinson]

As far as I remember none of these have exposed metal parts. They do however have a rather small valve hole which will get clogged fast if you transfer biological active water through it. The small size also limits flow.

Thank you. That is alright, it won't be moving much water and it'd be easy to push the gunk out if needed.

 

[Joe's Coral Reef]

How about a electronic controlled pvc ball valve?

https://www.aliexpress.us/item/3256803136539336.html?spm=a2g0o.productlist.main.5.7e925685vnlO18&algo_pvid=6aa00ab6-f021-4a3b-afb4-fac6085619ca&algo_exp_id=6aa00ab6-f021-4a3b-afb4-fac6085619ca-2&pdp_npi=4%40dis%21USD%2141.50%2141.50%21%21%2141.50%2141.50%21%402101fb1a17194945582326963e7e53%2112000025208017692%21sea%21US%21181891074%21&curPageLogUid=BvuV9YTVqQgu&utparam-url=scene%3Asearch%7Cquery_from%3A

 

[Dburr1014]

Also, I'm looking at the 'normally open' type and if my understanding is correct, the valve is normally open but closes when power is on and opens back up when the power is down again. Is this correct?

You are correct.
No electricity will be open, when energized it will close.

 

[Levinson]

How about a electronic controlled pvc ball valve?

https://www.aliexpress.us/item/3256803136539336.html?spm=a2g0o.productlist.main.5.7e925685vnlO18&algo_pvid=6aa00ab6-f021-4a3b-afb4-fac6085619ca&algo_exp_id=6aa00ab6-f021-4a3b-afb4-fac6085619ca-2&pdp_npi=4%40dis%21USD%2141.50%2141.50%21%21%2141.50%2141.50%21%402101fb1a17194945582326963e7e53%2112000025208017692%21sea%21US%21181891074%21&curPageLogUid=BvuV9YTVqQgu&utparam-url=scene%3Asearch%7Cquery_from%3A

Cool looking valve! but it is too big for me.

 

[BeanAnimal]

As far as I remember none of these have exposed metal parts. They do however have a rather small valve hole which will get clogged fast if you transfer biological active water through it. The small size also limits flow.

Almost all plunger type solenoid type valves will have exposed metal parts in the water path. The plunger (or part of it) is typically ferrite or has a metal coil and there is a spring in the water path. On higher end or specialty solenoids the plunger may be stainless or composite with an embedded magnet (or coil winding) and the spring may be stainless or composite (unlikely). Even then, most AC solenoid valves will also have an exposed AC shading coil. Finding one with only "reef safe" internals will be elusive and the valve will likely be extremely expensive.

This is why pinch valves are used in (low flow) applications where corrosives or volatile substances are being controlled. Depending on input pressure and flow requirements a peristaltic pump can also replace a valve (it is essentially a rotating pinch valve).

 

[Levinson]

Almost all plunger type solenoid type valves will have exposed metal parts in the water path. The plunger (or part of it) is typically ferrite or has a metal coil and there is a spring in the water path. On higher end solenoids the plunger may be stainless or composite with an embedded magnet (or coil winding) and the spring may be stainless or composite (unlikely). Even then, most AC solenoid valves will also have an exposed AC shading coil. Finding one with only "reef safe" internals will be elusive and the valve will likely be extremely expensive.

This is why pinch valves are used in (low flow) applications where corrosives or volatile substances are being controlled. Depending on input pressure and flow requirements a peristaltic pump can also replace a valve (it is essentially a rotating pinch valve).

Thanks! I just looked it up and pinch valves are quite expensive. I guess it's not really worth using electric valves.

 

[BeanAnimal]

what are you trying to do?

 

[Levinson]

what are you trying to do?

Well it's a little complicated and I don't need the valves. I was thinking of using a pump on a timer to suspend settled organics in an anaerobic chamber (which I plan on making in the future) then wondered if there was a way to seal both the inlet and outlet with electric valves when the pump turns on and reopen when the pump is off again.

 

[BeanAnimal]

Well it's a little complicated and I don't need the valves. I was thinking of using a pump on a timer to suspend settled organics in an anaerobic chamber (which I plan on making in the future) then wondered if there was a way to seal both the inlet and outlet with electric valves when the pump turns on and reopen when the pump is off again.

Just use a peristaltic pump on the output side and a check valve on the input side.

 

[Tavero]

Well it's a little complicated and I don't need the valves. I was thinking of using a pump on a timer to suspend settled organics in an anaerobic chamber (which I plan on making in the future) then wondered if there was a way to seal both the inlet and outlet with electric valves when the pump turns on and reopen when the pump is off again.

As I have written earlier most solanoid valves only have a tiny hole, which may get clogged almost instantly. At least this happened when I used them. I don't think you will be happy with the flow rate. I think they are only meant for clean water.

 

[Levinson]

As I have written earlier most solanoid valves only have a tiny hole, which may get clogged almost instantly. At least this happened when I used them. I don't think you will be happy with the flow rate. I think they are only meant for clean water.

Wow that hole is much smaller than I expected. Thanks for the great info.

 

[Dr. Reef]

We have 13 islands of fish in our warehouse on 1 apex and 1 ato pump.
13 water solenoids one for each sump.
We been using solenoids for a very long time, 20+ years.
I can tell you from experience, regular solenoid that close or open depending on the function eventually will lose their avibility to open or close. they malfunction all the time. In our case all solenoids are in closed position till power is applied and they come open and after power is cut off they go back to closed again. In our case they 100% of the time when they fail they fail in open position or dont close all the way causing the entire rodi reservoir in the sump and floor.
So we dont use them anymore. We use motorized ball valves. They make more noise opening and closing but there is no metal parts nor any chance of failure like the spring/regular solenoid.

 

[Dr. Reef]

1/2” UPVC Motorized Ball Valve - 9-36V AC/DC Plastic Electrical Ball Valve with Full Port, 2 Wire Auto Return, Normally Closed

U.S. Solid

ussolid.com

These are what we use.

 

[BeanAnimal]

I still use solenoid valves on rodi reservoirs, but in there is always a float as a fail-safe.

@Levinson the tiny hole is not what the water flows through, it is there to equalize pressure so that the solenoid is only pushing against the seal, not line pressure. But if it gets clogged, the solenoid will malfunction.

The ussolid valves are inexpensive and a good option.