MTS Systems 318 Series Product Information page 68

Prerequisite
Procedure
68 Operation
The crosshead is very heavy.
A dropping crosshead can crush hands, damage grips, and smash
specimens.
Observe the following precautions to reduce the possibility of unexpected
crosshead movement:
• Ensure that the crosshead is locked.
• The overhead crane and lifting chains must be able to support the weight of
the crosshead (see the Crosshead Weight table below).
• Center the crane directly over the load unit.
• Remove any slack in the lifting chains before unlocking the crosshead.
• Completely loosen all crosshead locking bolts before attempting to move
the crosshead.
• Keep the columns clean and dry. The crosshead cannot be securely clamped
to greasy or damp columns.
Before clamping the crosshead in place, you must have determined the proper
crosshead position and moved the crosshead to that position.
The crosshead can slowly drift down the columns if the locks are turned off
and when hydraulic pressure is turned off.
The crosshead can damage any test fixtures, grips, and specimen in its
path.
Unlock the crosshead only to reposition it. Always lock the crosshead after you
have repositioned it, and never leave the crosshead unlocked.
Tighten the crosshead clamping bolts according to the torque settings shown in
the following table. Torque the crosshead bolts to the values in Step 1 and so on
until Step 4 is complete. Use the same sequence as when you loosened the bolts.
L U S 1
OAD NIT TEP
318.10 20 N·mm
(15 lbf·ft)
WARNING
CAUTION
S 2 S 3
TEP TEP
171 N·m 190 N·m
(126 lbf·ft) (140 lbf·ft)
*
S 4
TEP
190 N·m
(140 lbf·ft)
318 Load Unit