Air Manifold

[dale farley]

Can someone tell me what the adjustments on the bottom of my air manifold are for. In the picture there are 12 of the adjustments with an aluminum hex nut and an adjusting screw in the center. I assume they are to adjust the pressure on the "in" and "out" sides of each switch, but I'm not sure. I thought I might be able to turn both adjustments off and prevent air going through the solenoid valve, but that's doesn't seem to be the case.

14714

[Gil_J]

Dale,

I believe those adjust the air flow rate, not the pressure.

[Joe Camper]

2 pocket doors a step slide an air seat and a bed lift. Right?

What was your thought process by wanting to completely shut them off?

[dale farley]

Joe, This manifold controls my step slide, bumper release, sun visors, slide locking pins, entry step, etc. The other things you mentioned are on another manifold. I was trying to isolate a leak, and I thought if the adjustment screws stopped all air to an item, I could turn them all off and determine where the leak was by turning them back on or off, one at a time.

[dale farley]

Gil,

There are 9 of the Solenoid Valves on this 10 station manifold. I can hear air leaking from at least one of the valves. (I took the valve off and put some gasket seal on it, but that made no difference.) I assume if I am hearing air at the valve, that means there is either a leak at the seal where the valve attaches to the manifold or there is an internal leak letting air bleed out through the line. I also assume there should be no air leave the manifold until one of the solenoids is activated? I disconnected the supply line to that manifold and reduced the leak to a fraction of what it was, so I know there is a problem related to that manifold. I also assume if there was a leak at the air piston, that would only leak when the solenoid was activated and would not cause a chronic leaking problem.

[Gil_J]

Dale,

The control valves for bidirectional devices, such as those controlled through this manifold, should have air supplied to the devices at all times. The solenoid simply controls which of the 2 hoses going to the device is being supplied air. The solenoid control valve should also open one of the two hoses to an exhaust port on that manifold.

It may be difficult to determine if a port is malfunctioning on the manifold without disconnecting the two lines feeding the device in question. The reason being is that the air ram supporting a device may have an internal leak that can result in a constant exhaust at the manifold.

[dale farley]

So the air that I am hearing could be a result of that valve exhausting when it should be closed??? This new/accurate info about the operation of the valve makes it more difficult to determine where the problem lies. Some of the rams are in very enclosed areas, not easily accessible, and I can't hear a leak through the walls. I assume I will have to attempt to remove both lines from the valve and cap them to determine if that valve or ram is the problem?

[Gil_J]

The air your hearing could be coming from an internally leaking air ram. Here's an easy test.

Disconnect the 2 lines at the manifold that goes to a suspect ram. Supply air to one line. The other line should have a quick gush of air and then it should not have any additional air coming from that hose. Now supply air to the other line and you should get the same results. If either had a continuous flow of exhaust air then the air ram is bad or is being supply too much air pressure.

[dale farley]

One of the valves is leaking continuously at the hole on the end opposite where the solenoid is located. The one that looks like small copper wires. Is this a problem with the valve or could this be the piston bleeding back through the valve?

[Gil_J]

Dale,

Is there a hose that connects to that or is that Ann exhaust port? If it's an exhaust port, it should only have air for a short time each time the solenoid changes state.

The best test for the air ram is to supply air to one of it's lines at the solenoid, but not through the manifold. There should only be air at the other line disconnected from the solenoid while the ram is moving. Then swap the hoses to check the ram in the opposite direction.

[dale farley]

Gil,

There is no hose connected to that port. About half of of the 10 valves on this manifold have two solenoids and half have only one solenoid and the open port which I assume may be the vent. Unfortunately, I am here by myself so I can't push the button to activate the solenoid and be at the manifold at the same time. I'm going to try to disconnect the lines tomorrow as you suggested and check to see if the piston is bad.

[Prodriver]

Gil.

Do you use any airline lub or antifreeze in the system or is it hard on these components? Thoughts? Can you get those solenoids rebuilt or are they inexpensive?

[Joe Camper]

The exhaust ports on those valves are identified by the gold porous filter that looks like a bunch of grains of sand glued together that's the exhaust port.

[Gil_J]

Dale,

Disconnect the solenoid and supply your own voltage and then you can do the job by yourself.

[Gil_J]

Kirk,

No I don't use any lube in these air controlled valves. I recently opened a bad Norgren valve I had and it was still well lubricate. I assume it was original. Some of these valves can be less than $100 and others several thousand for the specialty multi valve blocks.

Anti freeze...what's that? I'm in Florida.

[dale farley]

The valve I show here is about $100-120 according to where you buy it ($106 from Grainger). The valves with two solenoids are about $230 to 260.

Joe, It sounds like you are talking about the same port that I described and show a little earlier. This one has a continuous flow of air with power on it or power off. It bleeds until the system goes down to zero. These valves seem to be very specific in their operation. I tried replacing one with another that looked exactly the same but had one digit different in the number on the body. It totally did not function properly.

Based on my leaking port, I suppose the only way to determine if it is a valve problem or piston problem, is to do the test that Gil described on the disconnected lines.

[dale farley]

I tested the two air lines on the leaking valve, and they did exactly what Gil said they should. One burst of air as the piston was changing directions and then nothing. Neither side was leaking so I think I can safely assume I have a bad solenoid valve. I have ordered it so maybe that will solve the problem. Thanks Gil and Joe for the technical advice.