Enerpac ST-121 - Manual (Page 7)

Attaching Clamp Arm
1. Remove the retaining ring from the top of the plunger.
2. Slide the clamp arm down
over the plunger and use a
pliers to push the retaining
ring back onto the plunger
groove. Orient the
retaining ring so the
retaining ring gap will face
the back of the clamp arm.
See illustration.
3. Move the clamp arm up until it is firmly against the retaining ring and in the
desired position. While maintaining this position, torque the clamp arm bolt to
specification listed below.
A
CAUTION
Inadequate torquing of the clamp arm bolt could cause the arm to slip
during operation. BE SURE TO USE QUALITY GRADE 8 (8.8 DIN 912)
SOCKET HEAD CAP SCREWS (supplied with standard clamp arms).
Arms for Upper Flange Body Style
To use the upper flange body style cylinders,
you have to be sure that the contact bolt will
clear the upper flange during operation. The
clamp arm must be long enough for the contact
bolt to clear the upper flange as the arm swings
down. Clearance problems are most common
when the final clamping position is at the side of
the cylinder and the contact bolt must pass by
the front or back of the upper flange as it swings
down. You may need to use the longer, CAL
Series clamp arm for these applications.
Clamp Arm Bolt Torque
Cylinder Capacity Lubricated Torque
300 lbs (1,3 kN) 53-64 in-lbs (6,0-7,2 Nm)
500 lbs (2,2 kN) 12 to 15 ft-lbs (16,3 to 20,3 Nm)
1250 lbs (5,6 kN) 24 to 29 ft-lbs (32,5 to 39,3 Nm)
2600 lbs (11,6 kN) 44-53 ft-lbs (59,7-71,8 Nm)
Max.
Length
Contact
Bolt
Maximum Contact Bolt Length
Cylinder Capacity Maximum Length
300 lbs (1,3 kN) 0.55" (14,0 mm)
500 lbs (2,2 kN) 0.75" (19,1 mm)
NOTE: Maximum lengths provided here are for 300 and 500 lb. upper flange models only.
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