Solenoid valve issue

Thread Starter

koraud

Joined Feb 22, 2021
9
Hello,

I am trying to fix a pump and need to check a solenoid valve (KIP inc ref 1X 1006), but impossible to find data on it or the company website,
neither to check whether it is normally open or normally closed (although I think it is NC). I have no particular mechanical skills, so sorry if I'm not very clear.

So I'm looking for help on
-How to check whether it works or not (I used an app to try to find the permanent magnet and did not find one)
-Where to find more info on that specific model, unknown to google

Thanks for your help :)
 

Thread Starter

koraud

Joined Feb 22, 2021
9
hmmm from my understanding, there's a coil that generates a magnetic field in the body, and that pushes a permanent magnet in the mobile part? (Might be wrong... I don't know much physics)
 
That's a vacuum pump, which might change the approach. Here is a diagram of the pump. https://www.capvac.com/files/downloads/amEagPdf/welch/diagrams/Fixed/8917.pdf Is the solenoid in question, inside the pump.

Anyway, many times vacuum valves are operated by air. You might have air to open spring to close or air to open, air to close.

Simple solenoid valves consist of a plunger and a coil. The magnetic field moves the plunger.

They either fail to operate or they leak. They can also wear. Air may need to lubricated. If not, it can lead to premature failure.

Large vacuum valves are air to open and a spring closes the valve. It's held closed by the vacuum. Many times there is a bellows involved. That cracks and leaks.
 

Thread Starter

koraud

Joined Feb 22, 2021
9
Hmmm, I think I get it. My solenoid is piece 37-38, with 38 the plunger. 39 is a small rubber disc at the end of the plunger to prevent leaks. I disassembled that part and can't see any spring, so from my understanding, as there is a vacuum inside, it is opened when there is current, and closed by the vacuum when the current stops (power outage...) which prevents the oil from bumping into the air entry.
I'll check if I see any signs of cracks etc. tomorrow. Any idea on how to test the other parameters (leaks, total failure)?

If that helps, the problem overall is that the pump is not working (barely any vacuum), but all rotating pieces rotate, oil is new, etc. So I think the valve is closed even when the pump is on, which prevents air from entering
 
We gave up on rebuilding pumps. It wasn't worth the effort. We had about 7 systems using the same pump, so we evantually made all use the same twist-lock electrical plug. Initially they were hard wired.

The all got KF flanges on the output.

We sent them out to get rebuilt and they would come back painted. We did rebuild a turbo pump and always cryopumps and diffusion pumps. We would have the water lines done externally with stainless. The DP rebuildng os just cleaning. The cryo is easy.

The turbo is really messy. I never had to deal with an ION pump. We had one.

If the vacuum won't go down below 100-120 um, your looking at water.

Make sure no one left the purge on.

There is generally a ballast valve on the pump that can be used to release water.

Sometimes there is a heated trap.

Make sure you use the right oil.



One of our "test gizmos" was a thermal vacuum guage in a large rubber stopper. This takes everything but the pump out of th equation. make sure your guage is good. Don't try to plug leaks with your finger.
 

Thread Starter

koraud

Joined Feb 22, 2021
9
OK, thanks for the advice!
The vacuum is so bad (Maybe 0.8/0.9 atm compared to 0.1 torr normally) that it can't just be water (we changed the oil, too, so we got rid of any possible water and it did not solve the issue)

I'll try to get more precise values with the rubber stopper/gauge method, but I would need to reassemble the pump first, so I'll try to check individual components first (motor OK, oil OK, casing OK, so still need to find a way to check the solenoid and its alimentation. No clue of what other component could be faulty).

Obviously, before disassembling the pump, we made sure the pump was the problem, and there are no major leaks in the system
We have two filters on the pump and one cold trap for water. We cleaned the filters, checked the cold trap.

Oil grade was good (from pump maker) when the pump broke. For the tests, we use a less expensive version, that has same density, viscosity and temperature range (+- 1%). We don't expect to reach perfect vacuum with that oil, but at least we'll know when the problem is fixed.

We also have KF flanges

Is the purge the oil purge? If yes, It had not been touched for months when the pump broke.
For the ballast, we do have one, and it's working fine
 

Thread Starter

koraud

Joined Feb 22, 2021
9
OK. So, to check the resistance I unplug the solenoid and plug my ohmmeter on the cables. I except low values (a few ohms). High values would indicate a broken coil.
Just one issue: I only have one cable that goes in the solenoid. Does that one cable contain both "+" and "-" cables? (even in AC, there should be 2 cables, right?)
 

Thread Starter

koraud

Joined Feb 22, 2021
9
The app works well (I tried it with permanent magnets), although its probably not very precise. Should be enough to check if the coil works, though.
I don't think I have any relays (I just have a single pump), but I'll make sure I check all electrical contacts too. Thanks :)
 
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