When air flows out of the supply tank, it is prevented from returning by a
one way check valve .
When draining the tanks, the supply tank should always be drained first to prevent accumulated moisture flowing into the next tank being drained.
When the supply tank is drained first, any accumulated moisture is removed before it can pass further into the system.
Remember: Always drain the supply tank first.
If your Truck has air it must have An air pressure gauge
to show the pressure available for Safety.
Low air pressure warning devices
Compressed air can be hazardous