DESCRIPTION OF OPERATION
Page 4
In released position, the supply valve is closed to
supply pressure and “out” port is open to exhaust.
Note in the diagram, when the roller is forced down
to increase pressure, it pushes down the pressure
control plunger, closing the lower exhaust valve and
opening the upper supply valve which permits air to
flow to out port delivery and the upper diaphragm
chamber. As the pressure builds up in the delivery
line it acts through the sensing port orifice and
deflects the control diaphragm downward,
compressing the control spring. When sufficient
diaphragm deflection is reached to allow the upper
supply valve in pressure control portion to close, the
pressure in the delivery line is held to that value.
The value of the pressure delivered to the outlet port
is proportional to the pressure control plunger
movement. This movement in turn is controlled by
the roller and is therefore proportional to the roller
travel.
The CONTROLAIR Valve will automatically
compensate for downstream air pressure changes
in the graduated pressure delivery line. These air
pressure changes can be caused by line leakage,
temperature change or load feedback. If air
pressure at the outlet port increases over that called
for by roller position, the diaphragm in the control
portion will deflect downward opening the lower
exhaust valve and exhausting air until the original
setting is obtained. If the pressure drops below that
called for by the handle position, the decreased
force on the diaphragm will allow the control spring
to force the diaphragm upward, opening the upper
supply valve to restore the set pressure.
The range of pressure is controlled by the strength
of the diaphragm spring. Various values are
available as shown on Identity Schedule, page 5.
Outlet
VALVE
FUNCTION
Exhaust
Inlet
ASSEMBLY VIEW
Range Control
Spring
Exhaust Port Adjusting Screw
Diaphragm
Exhaust
Valve
Supply Valve
Inlet & Exhaust
Valve Unit
CAM Roller
Assembly
CAM Roller
Adjustment
DIAGRAMMATIC VIEW
To Next Page
