Enerpac ST-121 - Manual (Page 6)

INSTALLATION
These Swing Cylinders are designed so that you can set the position of the clamp
arm after mounting the cylinder. If you need to change the rotation direction, do it
before mounting the cylinder.
Changing Plunger Rotation (if needed)
Change plunger rotation by lining up the letter on top of the plunger with the arrow
on the side of the cylinder opposite the ports. To change rotation, refer to
illustrations and follow procedure below. You will need a spanner wrench.
1. Position the arm on the plunger to provide a handle to grasp for moving the
plunger.
(a) Release the clamp arm bolt.
(b) Remove the retaining ring and slide the clamp arm down the plunger until
the top of the arm is 0.25" (6 mm) from the top surface of the plunger.
(c) Tighten the clamp arm bolt. DO NOT discard the retaining ring.
2. Place spanner wrench on bottom cylinder plug and turn the plug (facing you)
counter-clockwise 4 turns.
NOTE: Single-acting cylinders may need the bottom plug to be rotated more
than 4 turns to help relieve return spring tension.
3. Push down on the plunger and rotate it to line up the desired letter (L, R, S) with
the arrow on the side of the cylinder.
4. Once the letter and arrow are lined up, pull the plunger up, turn the bottom plug
back in (clockwise) 4 turns, and tighten firmly.
A B
S
L R
Clamp and
Unclamp Position
STRAIGHT
Clamp Port Unclamp Port
A B
Clamp Position
RIGHT SWING
Clamp Port Unclamp Port
R
S
L
Unclamp
Position
A B
Clamp Position
LEFT SWING
Clamp Port Unclamp Port
Unclamp
Position
L
R S
.25"
(6,4mm)
Retaining ring
removed
from groove.
Clamping
Arm
Clamp
Arm
Bolt
Plunger Approx.
4 turns out.
Bottom plug
6