F-1031, Section 2119
Page 20 of 24
Air Compressor Shutdown
When the air compressor is shutdown or disengaged, the following occurs:
·
The master pressure gauge registers compressor
sump tank pressure.
·
The compressor rotors stop turning and the compres-
sor outlet and inlet pressures equalize.
·
The shuttle valve sees equal pressure on the shuttle
piston. Since the inlet pressure side is larger than the
discharge pressure side, the shuttle valve opens (see
Shuttle Valve Function).
·
With the shuttle valve open, air from the compressor
discharge side is allows to exhaust through the gray
air bleed outlet port. This slowly relieves all air pres-
sure from the compressor and the sump tank.
·
In shutdown, the fixed air regulator and balance valve
do not control the air circuit or have any influence.
They are basically bypassed.
·
The auto-sync solenoids are also bypassed and it
doesn’t matter whether they are opened or closed.
They have no influence on shutdown.
Pressure Hazard.
May cause serious personal injury.
In shutdown, the control air circuit only relieves air
stored in the compressor and sump tank. Air down-
stream of the minimum pressure valve is not released
through the control air circuit. Pressurized air may be
trapped in discharge piping and hoses.
WARNING
!
Air Compressor Shutdown
Red Hose
Red Hose
Blue Hose
Gray Hose
Water Pressure
Air Pressure
Y
e
ll
o
w
Ho
s
e
Re
d
H
o
s
e
Bl
u
e
H
o
s
e
Black Hose
Black Solenoid
(Open or Closed)
Master Air Pressure Gauge
Water Pump
Balance Valve
(Open)
Balance
Trim Valve
(BTV)
Shuttle Valve
(Open)
Minimum
Pressure
Valve
Air / Oil Separator
Air Inlet
Valve
(Closed)
Air Inlet Trim Valve (AITV)
Air Bleed Off
Fixed Air Regulator (Closed)
Oil Scavenger Line
Black Hose
Yellow Solenoid
(Open or Closed)
Air
Compressor
