CONTROL HEAD MODEL 200AV, 220TV
The Variable Volume Control Head mounted on a standard TriRotor pump body allows for both automatic and/or
manual changes in the flow rate of the pump. The automatic response occurs with changes in the
operating pressure of the system, causing a spring-loaded hydraulic control mechanism to adjust internally, the
stroke of the pump. By using flow controls, the operator can make manual adjustments to increase or decrease
the discharge rate as desired.
AND VERNIER FLOW CONTROLS
Two flow controls are available: The Manual Flow Control (MFC) for rough adjustments, or Vernier Flow Control
(VFC), which is graduated for fine setting and metering. These enable the operator to vary the discharge rate
infinitely from 100% down to zero without stopping the pump or changing speed. The plunger under the control
stem and control lever assembly fix the stroke length, i.e. displacement of the pistons.
ADJUST CONTROL SPRING TENSION
1 - STOP PUMP. Unbolt lettered spring cap and insert spring adjusting wrench as
shown. Pull wrench toward "increase" and remove pawl pin. DO NOT LET
WRENCH GET AWAY. NOTE alignment of holes between pawl plate and
underlying top spring plate. Unwind to release spring tension, counting number
of top spring plate holes passing hole originally containing pawl pin.
2 - To reset, pull wrench in direction
"increase" ( note arrows on plate) until
the spring begins to tighten against the
control lever assembly. Note first coinciding
set of holes. Thereafter, continue
turning wrench until second top spring
plate hole is seen. Insert pawl pin to lock top spring plate in
this position. Pump will now develop approximately 35 PSI
when running against a closed discharge line.
3 - For greater pressure, turn wrench to higher hole position.
Each hole represents 20 PSI, DO NOT EXCEED 6 holes.
Spring adjusting wrench is designed to bend if operator exceeds
the allowable tension.
REVERSE DIRECTION OF ROTATION
CAUTION: After reversing rotation, variable head no longer
automatically reduces discharge rate. A relief valve should
be installed in the discharge line. For automatic operation,
order a complete head of opposite rotation from the factory
1 - Release spring tension as described above.
2 - Unbolt control head and remove together with
pressure control plate and gaskets as one unit
(pictured). Make sure gaskets are not damaged.
3 -Unbolt shaft housing and remove together with rotor group and gasket as one unit.
LEAVES PUMP IN THREE SECTIONS AS PICTURED.
4 - Turn body "about face" and switch dowel pins.
5 - Bolt the three sections back together, making sure the shuttle pin enters the bore of the shuttle.
6 - Reverse the wiring to run motor in opposite direction. NOTE: Variable head no longer automatically reduces discharge rate. Refer to caution above.