When the handle is in released position, the
“IN” port is closed to supply pressure and the
“OUT” port is open to exhaust.
Note in the diagrammatic, when the handle is
pushed forward to increase pressure, the
cam forces the cam follower to push down
on the inlet and exhaust valve unit by closing
the exhaust valve and opening the supply.
This permits air to flow to the “OUT” port and
the upper diaphragm chamber. As the pres-
sure builds up in the delivery line, it acts
through the sensing port orifice and deflects
the control diaphragm downward, compress-
ing the control spring. When sufficient dia-
phragm deflection is obtained to allow the
upper supply valve in the 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
graduating portion plunger movement. This
movement in turn is controlled by the cam
contour and is proportional to the handle
travel.
The H-2 Controlair Valve will automatically
compensate for delivery (outlet) line air pres-
sures changes. These air pressure changes
can be caused by line leakage, temperature
change or load feedback. If air pressure at
the delivery (outlet) port increases over that
called for by the handle position, the dia-
phragm 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 de-
creased force on the diaphragm will allow the
control spring to force the diaphragm up-
ward, opening the upper supply valve to re-
store the set pressure. The range of the de-
livery (outlet) line pressure is controlled by
the strength of the diaphragm spring.
Page 5
Description of Operation
For H-2 Controlair®
