Instruction Manual
D104483X012
785C Actuator
May 2022
12
Manual Hydraulic Handpump Operation
If manual operation is required, actuator sizes 435, 485, 535, 585, 635, and 685 should be equipped with a manual
handpump as standard construction.
Note
The manual handpump control unit must be installed in vertical up direction per figure 7. For application requiring actuator
horizontal installation, a special design handpump support and hydraulic tubing must be used to install handpump in vertical up
direction per figure 7. Contact your Emerson sales office for further information of manual handpump for actuator horizontal
installation
.
Figure 7. Handpump Orientation
HANDPUMP CONTROL UNIT
MUST BE INSTALLED IN
VERTICAL UPRIGHT DIRECTION
GRAVITY
DIRECTION
GH15114 sheet 1
A bypass assembly is furnished only when an actuator with manual override is specified. The bypass assembly allows
the pressure to equalize on either side of the actuator piston, so that the manual override can be used to position the
control valve. Flow through the bypass tubing is controlled by an angle needle valve, which is operated manually. This
valve should be closed when supply pressure is being used to operate the actuator.
The following steps are referenced in figures 8, 9, and 10. Refer to table 7 for handpump specifications and figures 11
through 17 for handpump schematics and more detail instructions.
1. Select “Manual Opening” or “Manual Closing” by rotating the Engagement/Disengagement
handle as indicated on
the instruction plate from pneumatic operation “REMOTE” mode.
position of the actuator is reached.
3. Check the correct operation of the actuator through the visual travel indicator.