Ronmar
Well-known member
- 3,577
- 7,054
- 113
- Location
- Port angeles wa
Ok, maybe some clarification is in order. There are 2 valves on the air dryer. One is a safety relief valve. On the original dryers it is on the top(i‘m pointing at it in the pic), not sure where it is on the Haldex units. Like a popit type safety on any air compressor, under normal conditions it should not ever be venting air as it is there to keep from blowing something up if the governor sticks/fails. When the compressor is on line, you can lift/wiggle the knob in the pic and get air to vent. When the compressor is offline, the dryer has been purged and you wont get any air out of it...
the second valve is the purge valve. there are 2 lines running to the governor. One from the wet tank, one from the air dryer. Every time the governor reaches its set pressure sensed in the wet tank and unloads/shuts off the compressor, it sends air down that purge line to the dryer which causes the dryer to vent its internal air up to the check valve At the top outlet port. This causes a Puff of air out the bottom port Where the valve is located and where the water that coalesced from the air has collected, venting that water to the atmosphere. The dryer purges every time the compressor reaches the governor set pressure. The frequency at which this happens depends upon how much air you are using/how often the compressor cycles on and off...
Your governor should be set at 120-125 PSI measured at the wet tank. The rig with the gauge and blowgun is handy for checking/setting it. It must go over 115-117 PSI to close the CTIS pressure switch on the wet tank otherwise CTIS wont function...
![18A1541E-0B73-49CF-99D5-E4FD23862FBB.jpeg 18A1541E-0B73-49CF-99D5-E4FD23862FBB.jpeg](https://www.steelsoldiers.com/data/attachments/564/564490-0c7b714385fcdc96598423e8ef0b508a.jpg)
the second valve is the purge valve. there are 2 lines running to the governor. One from the wet tank, one from the air dryer. Every time the governor reaches its set pressure sensed in the wet tank and unloads/shuts off the compressor, it sends air down that purge line to the dryer which causes the dryer to vent its internal air up to the check valve At the top outlet port. This causes a Puff of air out the bottom port Where the valve is located and where the water that coalesced from the air has collected, venting that water to the atmosphere. The dryer purges every time the compressor reaches the governor set pressure. The frequency at which this happens depends upon how much air you are using/how often the compressor cycles on and off...
Your governor should be set at 120-125 PSI measured at the wet tank. The rig with the gauge and blowgun is handy for checking/setting it. It must go over 115-117 PSI to close the CTIS pressure switch on the wet tank otherwise CTIS wont function...
![18A1541E-0B73-49CF-99D5-E4FD23862FBB.jpeg 18A1541E-0B73-49CF-99D5-E4FD23862FBB.jpeg](https://www.steelsoldiers.com/data/attachments/564/564490-0c7b714385fcdc96598423e8ef0b508a.jpg)
Last edited: