MTS Advantage Pneumatic Grips User Manual

Page 51

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Installing a Specimen

Advantage™ Pneumatic Grips

Operation

51

Improper specimen installation can damage the grip faces.

To prevent damage to the grips, install the grip faces precisely as specified in the
following steps.

1. Adjust the grip pressure to the maximum level as determined in

“Adjusting

the Air Supply Pressure”

on page 53.

2. Apply power to the load frame or load unit.

3. Release the upper and lower grips.

Note

If you are using flat wedges in the 10,000 N grips, loosen the cap screws
securing the specimen guides on the wedges. Adjust the specimen
guides so as to allow the specimen to be centered in the grip. Tighten the
socket head cap screws.

4. Place the specimen in the lower grip allowing a space of at least 3 mm (0.12

in) but not greater than 6 mm (0.25 in) between the bottom of the specimen
and the bottom inner edges of the lower grip wedges. Lock the lower grip.

5. Lower the crosshead or extend the actuator until the specimen is positioned

in the upper grip allowing a space of at least 3 mm (0.12 in) but not greater
than 6 mm (0.25 in) between the top of the specimen and the inner top edges
of the wedges. Lock the upper grip.

Specimen slippage during the test can damage the grips.

Specimen slippage typically occurs when:

• Insufficient grip pressure is used to securely grip the specimen

• Grip faces or wedges with rounded or flattened serrations are used

• A specimen is harder than the wedge or face material

Do not exceed the maximum pressure rating of the grip. Increasing the pressure
setting to hold round specimens can reduce the life of the vee-notched wedges.

CAUTION

CAUTION

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