MTS Series 322 Load Frames - Manual (Page 57)

Series 322 Load Unit Operation 57
Load Unit: Position the Crosshead Hydraulically
1. This step pressurizes the lift actuators. The crosshead might have shifted
position while hydraulic pressure was turned off.
Briefly turn the Crosshead Lift/Lock Controls to the lift crosshead
position to apply a slight upward pressure to the crosshead.
Then return the lift control to the stop position.
2. Use the Crosshead Lift/Lock Controls to unclamp the crosshead.
Wait 30 seconds for the pressure in the crosshead locks to drop to zero.
Note Always lower the crosshead to where you want it. The pressure
remaining in the lift cylinders after raising the crosshead can slightly shift
its alignment. Lowering the crosshead to its final position removes this
pressure and improves alignment.
3. Use the Crosshead Lift/Lock Controls to move the crosshead to a point
where you can install the specimen (or specimen fixture) into the upper grip
or fixture without obstruction.
Set the control to the stop position “O” before proceeding.
4. Use the Crosshead Lift/Lock Controls to clamp the crosshead to its current
position.
Wait 30 seconds for the locks to fully clamp the columns.