Solenoid valves

BrainBandAid

BrainBandAid

New member
Anyone have experience using those little plastic solenoid valves from dishwashers, washing machines, or ice-makers? I've never really looked at one, but from pictures, I can't see any metal...

I was thinking of using one for my RO/DI inlet, or maybe an auto-top-off.
 
Re: Solenoid valves

<a href=showthread.php?s=&postid=8206090#post8206090 target=_blank>Originally posted</a> by BrainBandAid
Anyone have experience using those little plastic solenoid valves from dishwashers, washing machines, or ice-makers? I've never really looked at one, but from pictures, I can't see any metal...

I was thinking of using one for my RO/DI inlet, or maybe an auto-top-off.
Click to expand...

I heard that landscape sprikler system 12 volt valves work, but I haven't tried them. You can find them at Lowes or Home Depot.
 
If you order the "McMaster" valves, order DC valves. The AC valves ALL have copper shading coild that are wetted.

Bean
 
www.airwaterice.com sells them for RO systems.
The ones used in icemaker/water dispensor on Fridges are mostly plastic but they do have a stainless plunger inside, I have been using one for a year and so far no problems.
 
IF it is an AC valve it has a copper coil inside it that is wetted. It is called a "shading coil" and helps reduce the amount of current required to keep the valve open.
 
<a href=showthread.php?s=&postid=8215770#post8215770 target=_blank>Originally posted</a> by BeanAnimal
IF it is an AC valve it has a copper coil inside it that is wetted. It is called a "shading coil" and helps reduce the amount of current required to keep the valve open.
Click to expand...

Can you explain that one to me. I have a few 110vac solenoids from mcmaster and havent seen any water going to the coil.

Thanks
Don
 
Never seen water go in any of mine either. The only one thing I know for sure is that you don't power up these units DRY. They use the water traveling thru the opening to cool the coils plastic housing and if they are left on too long dry they burn out, almost melting the plastic.
 
Donw (and others)

solenoid coils can come in TWO basic types:

DC (Direct Current)
AC (Alternating Currnet)
... not being a smartass, just being clear for those who DON'T already knwo that.

A DC solenoid passes current in one direction and therefore the magnetic field created by the coil is constant (unipolar). When the plunger is armature is sucked into this field it stays put until released.

A AC solenoid creates a magnetic field, but this field alternates between poles 60 times a second. Because the Armature starts OUTSIDE the field, when power is applied it DOES get pulled into the field. However because the field alternates, the armature tends to 1) chatter and 2) have a weak holding power.

To overcome the problems with the AC solenoid, a simple loop of copper is placed at the ends of each pole. This copper has current induced into it by the main coil (somewhat like a transformer) Because this coil becomes saturated, it lags behind the alternating field created by the main coil. This creates a secondary magnetic field that does not colapse in the same partial cycle as the main field. This reduced the chatter (hum) and creates more holding power.

Sorry if my explanation is confusing or not well worded... I am sure in todays age, you will find a much better answer than that on google.

In any case the shading coil in MOST AC solenoids is wetted. If you unscrew your main coil from your solenoid body, you will see it. You can find AC solenoids that do not have wetted shading coils, but you will pay several hundred bucks for one. Hayward makes one. Asco Scientific used to also... I think now they only make pinch valves. SOME of the ASCO higher end stainless valves use a SILVER shading coil. Again, most of these are VERY EXPENSIVE.

In any case most of the solenoids you see on McMaster (ASCO REDHATS, KIP, etc) have a solenoid that does get wet. The main coil is usually encapsulated and has a plastic, brass, stainless, or other non corrosive inner barrier between the armature and the copper coils.

If I can find an AC solenoid in the parts bin I will try to get some photos.
 
Sorry Bean I paid $12 for mine and it's AC with no part on any coil that gets wet. Believe me I burned up 2 of these running them dry and I pulled them apart and saw nothing like you describe.
 
Guys, if it is a direct acting AC solenoid, then it has a shading coil, its that simple.

Let me say this very plainly one more time.

There is a COIL of wire wrapped around an piece of Iron. It is the main coil that creates the magnetic field. The solenoid is pulled into this coil. The coil is sperated from the water by metal or plastic. However at the very end of the coil, there is a small copper ring that is in contact with the water. On some of the more expensive solenoids, this "shading coil" may be made of silver.

No Don, I did not say you would find wet copper "WINDINGS". At this point I am not sure if you are honestly asking questions to learn, or just playing the devils advocate to fuel an arguement.

Robby, no need to be sorry, but your are more than likely (99.9999999999%) wrong about what you think is wetted. Take the coil off, look down inside it. At the very end you will see a little copper ring.

This is AC solenoids 101 guys... without the shading coil the AC solenoid would HUM or CHATTER. The shading coil makes contact with or nearly makes contact with the armature... therefore it must be wetted. Placing it behind epoxy severly degrades its effect. A larger main coil and shading coil would have to be used to generate the same amount of holding force. This means more cost, more heat etc...

I am not sure why there is such resistance to accept something that is so basic to the operation of the device.
 
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<a href=showthread.php?s=&postid=8220677#post8220677 target=_blank>Originally posted</a> by BeanAnimal
Guys, if it is a direct acting AC solenoid, then it has a shading coil, its that simple.

Let me say this very plainly one more time.

There is a COIL of wire wrapped around an piece of Iron. It is the main coil that creates the magnetic field. The solenoid is pulled into this coil. The coil is sperated from the water by metal or plastic. However at the very end of the coil, there is a small copper ring that is in contact with the water. On some of the more expensive solenoids, this "shading coil" may be made of silver.

No Don, I did not say you would find wet copper "WINDINGS". At this point I am not sure if you are honestly asking questions to learn, or just playing the devils advocate to fuel an arguement.

Robby, no need to be sorry, but your are more than likely (99.9999999999%) wrong about what you think is wetted. Take the coil off, look down inside it. At the very end you will see a little copper ring.

This is AC solenoids 101 guys... without the shading coil the AC solenoid would HUM or CHATTER. The shading coil makes contact with the armature to enhance its effect... therefore it must be wetted.

I am not sure why there is such resistance to accept something that is so basic to the operation of the device.
Click to expand...

Please dont be offended I really was just asking a question and your techno info was honestly over my head. I did come home and take apart one of the solenoids and think I see the metal piece your talking about. I have a few more on order and will post up a pic when they come in.

Don
 
Hey BeanAnimal

Hey BeanAnimal

Have you seen the valves on page 420 of the McMaster catalog?
The bodies are Delrin, PVC, CPVC, polypropylene and polycarbonate. The Delrin and polycarbonate are reasonably priced. In the Delrin you can get Viton or Buna-N seals. Which do you think would be better?
 
Not offended at all Don.. your usually (always) a stand up guy with good intentions and a level headed approach to anything mechanical. Looking back at my post, I guess I should have chosen my words better. Between you and Robby, I felt like I was being doubted jsut for the sake of it :)

That said: I don't think that the small amount of copper will be a problem when used with RO/DI. I just wanted to make people aware of the construction and that the DC valves don't have that "feature". Some people have also mentioned using these with water change systems and/or dosing systems. The copper in that situation is a totaly different story.

Joker... I wouldn't worry about the type of seals, they will all last a long time with water. I think the DELRIN valve has some brass in it as well (or one of the "plastic" valves does. This is "as reported" from a few others who have purchased them). I know nothing about hte PVC and CPVC valves, as I never looked into them or tried to track down the OEM.

The "polycorbonate" valve with the integral John Guest Fittings has ONLY STAINLESS wetted parts in the DC models. If you choose AC then of course it has the copper. The valve is a "KIP Q2" valve made by KIP (a NORGREN company). I tracked down the manufacturer (McMaster would not give me the info) by cross referencing the CSA and C2 aproval numbers. I contacted a norgren tech support engineer and had him pull the manufacturing specs (not the useless specs on the websites). There are several different grades of stainless used, but it is all (the wetted parts) stainless (in the DC model).

Bean
 
I've used TORO Sprinkler Solenoid Valve from home depot that uses 24V AC. It worked for the last 2 years still working. I used a door bell transformer to power it up. I use this to turn on the RODI. I think it was less that 10 bucks. This one has a plastic plunger and no exposed coils that can come in contact with water.
I used a Icemaker solenoid and it lasted only 2 days. They are only designed to turn on for only few minutes.
83799IMG_0704.JPG
 
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