Jettronics Dual Air Valve problem
08-11-2011, 03:16 PM
#1
Jettronics Dual Air Valve problem
Hi,
I have a Jettronics Dual Air Valve that appears to leak air after being cycled if the pressure is above 50PSI.
I am able to pressurize the tank to 100PSI and the air valve doesn't leak at first but when I cycle the retracts air continues
to leak out the exit port for several seconds after the retracts have already cycled and doesn't stop until the pressure drops to about 50PSI.
If I cycle the retracts again there is no prolonged escape of air leak at the valve, it only happens when the tank is fully pressurized. At first I
assumed I had a defective air valve so I installed another valve that I had purchased for a different project and it behaves the exact same way.
Since I have two valves behaving the exact same way I'm beginning to wonder if I'm doing something wrong but I really can't see what that could
be. Any suggestions?
Thanks
Wayne
I have a Jettronics Dual Air Valve that appears to leak air after being cycled if the pressure is above 50PSI.
I am able to pressurize the tank to 100PSI and the air valve doesn't leak at first but when I cycle the retracts air continues
to leak out the exit port for several seconds after the retracts have already cycled and doesn't stop until the pressure drops to about 50PSI.
If I cycle the retracts again there is no prolonged escape of air leak at the valve, it only happens when the tank is fully pressurized. At first I
assumed I had a defective air valve so I installed another valve that I had purchased for a different project and it behaves the exact same way.
Since I have two valves behaving the exact same way I'm beginning to wonder if I'm doing something wrong but I really can't see what that could
be. Any suggestions?
Thanks
Wayne
08-11-2011, 10:32 PM
#2
RE: Jettronics Dual Air Valve problem
Wayne
Unlikely to be the Jet Tronic valve, more likely a cylinder is leaking and the air travels from one side of the cylinder to the other and then the air comes out of the vent (which is there to allow the displaced air out)
Use a pair of hemostat pliers to lock off each cylinder in turn to see which one (ones) are leaking (sqush the tube going to the cylinder) (which cylinder manufacturer-china?)
If you find a leak really you will need to replace them, lubricating is a short term fix. Robart or Ultra Precision is where you should look.
Regards
Dave
Unlikely to be the Jet Tronic valve, more likely a cylinder is leaking and the air travels from one side of the cylinder to the other and then the air comes out of the vent (which is there to allow the displaced air out)
Use a pair of hemostat pliers to lock off each cylinder in turn to see which one (ones) are leaking (sqush the tube going to the cylinder) (which cylinder manufacturer-china?)
If you find a leak really you will need to replace them, lubricating is a short term fix. Robart or Ultra Precision is where you should look.
Regards
Dave
08-12-2011, 06:27 AM
#5
RE: Jettronics Dual Air Valve problem
Wayne,
Dave is right on the money with his suggestion. Everyone points the finger at the valve when you may have one or more leaky cylinders. IF this is the case you have three possible fixes:
1. lube the cylinder as a first point of call with silicone oil. This will help if the problem is an out of shape o-ring that is twisting during the piston movement.
2. pull the retract cylinder apart and apply grease (silicon grease from dive shop) and replace o-ring if necessary
3. if neither of the above work, remove the o-ring and put a few wraps of teflon tape around the deepest part of the o-ring recess (after cleaning up first), lube up and replace the o-ring...this will increase the squish on the o-ring and has worked well for me in the past.
Dave's suggestion for diagnosing the problem is absolutely correct.
Hope that helps.
Craig.
Dave is right on the money with his suggestion. Everyone points the finger at the valve when you may have one or more leaky cylinders. IF this is the case you have three possible fixes:
1. lube the cylinder as a first point of call with silicone oil. This will help if the problem is an out of shape o-ring that is twisting during the piston movement.
2. pull the retract cylinder apart and apply grease (silicon grease from dive shop) and replace o-ring if necessary
3. if neither of the above work, remove the o-ring and put a few wraps of teflon tape around the deepest part of the o-ring recess (after cleaning up first), lube up and replace the o-ring...this will increase the squish on the o-ring and has worked well for me in the past.
Dave's suggestion for diagnosing the problem is absolutely correct.
Hope that helps.
Craig.
