Instruction Manual
D103317X012
VBL Volume Booster
May 2017
6
Operating Information
The only operating requirement of the volume booster is the adjustment of the bypass restriction for stable actuator
performance. Although systems with different characteristics may require different adjusting techniques, the
following adjustment procedure is recommended when using the actuator for throttling control.
Note
When sizing the booster, select the lowest C
v
that will meet the stroking speed specifications. Oversizing the booster in a closed
loop may lead to stability problems, thus requiring the bypass to be opened so far that the booster will never operate.
Prior to operation, turn the bypass restriction adjusting screw (figure 3) four or five turns counterclockwise from the
fully closed position. With the actuator in operation, slowly turn the restriction clockwise until the booster operates in
response to large changes in the input signal, yet allows small changes to move the actuator without initiating booster
operation.
Figure 3. Volume Booster Sectional View
GE26237-Section
UPPER DIAPHRAGM
DIAPHRAGM PLATE
ASSEMBLY (INCLUDES
LOWER DIAPHRAGM)
DIAPHRAGM SPACER
LOWER SPRING
VALVE PLUG
ASSEMBLY
LUBRICANT
HOUSING, TOP
HEX SCREW
EXHAUST PORT
EXHAUST
OUTPUT TO
ACTUATOR
SUPPLY PORT
END CAP
SPRING SEAT
UPPER SPRING
BYPASS RESTRICTION
ADJUSTING SCREW
SUPPLY
HEX NUT
PIN, SLOTTED
SPRING
BYPASS VALVE
O‐RING
HOUSING, BOTTOM
O‐RING
INPUT
SIGNAL
If the actuator is to be used for on‐off control, the restriction should be closed (turned fully clockwise).
Verify that the capacity of the regulator meets the stroking capacity requirements.