DeZURIK
R3 PowerRac
TM
Cylinder Actuator
D10359
Page 4
August 2016
Description
The R3 PowerRac Cylinder Actuator is a quarter-turn double-acting enclosed rack and gear cylinder
actuator. The actuator is used for on-off or modulating control of butterfly valves and other valves that
have a square or double-D shaft connection. A choice of an 8" (200 mm) or a 10" (250 mm) diameter
cylinder is offered. A lockable model is available as an option.
Installation
The actuator requires two pneumatic connections— one to each port on opposite ends of the cylinder.
Air to the connection closest to the actuator drives the actuator clockwise, towards the “shut” position
on the dial; air to the connection farthest from the actuator drives the actuator counterclockwise,
towards the “open” position on the dial. The 8" (200 mm) cylinder has ½" NPT connections, and the 10"
(250 mm) cylinder has ¾" NPT connections.
Operation
The R3 PowerRac Cylinder Actuator is powered pneumatically, and rotates 90° between the open and
closed positions. The cylinder is sized for 60 psi or 80 psi (415 kPa or 550 kPa), and is limited to 100
psi (690 kPa) maximum.
Lubrication
The R3 PowerRac Cylinder Actuator is lubricated at the factory, and does not require routine
maintenance lubrication. If the actuator is disassembled, lubrication is required as described in the
Actuator Reassembly
section.
Open and Closed Position Stops
The adjustable open and closed position stops prevent the actuator from rotating beyond the open and
closed positions of the valve. If the actuator is factory-mounted on the valve, the stops are preset, and
do not require further adjustment. If the actuator is not factory-mounted on the valve, or if the actuator is
removed and/or disassembled, the stops will require adjustment as described below. Refer to the Valve
Instructions for closed-position information, and adjust the stop screws after the actuator is mounted on
the valve.
The adjustable stop screws are secured with jam nuts, and are located in the extreme ends of the
actuator as shown in Figures 1 and 2. The closed position stop is located in the cylinder cap, and the
open position stop is located in the end cover. To adjust either stop screw, loosen the jam nut and turn
the screw counterclockwise to increase the stroke, or clockwise to decrease the stroke. After the stop is
adjusted to the desired position, hold the screw from turning, and tighten the jam nut.
