MTS Series 685 Hydraulic Grip Supply - Manual (Page 36)

Series 685 Grip Supply Product Information 36
About Rate Control
Operation
the maximum output pressure of the hydraulic grip supply. The maximum output
pressure is different for each model:
• The maximum output pressure of the Model 685.10 and Model 685.60
Hydraulic Grip Supplies can be factory set to 45 MPa (6500 psi) or 68 MPa
(10,000 psi).
• The maximum output pressure of the Model 685.22 Hydraulic Grip Supply
is 21 MPa (3000 psi).
1. Determine the required grip operating pressure.
See “Determining the Grip Operating Pressure” and also see the grip
manual.
2. Install the specimen and turn both grip controls to the grip position
(clockwise).
3. Make sure that the hydraulic grip supply is turned on.
Note If this procedure is being performed for the first time since the hydraulic
grip supply was installed, make sure that the 1/2 inch NPT plug was
removed from the top of the reservoir and that the breather was installed
in its place.
4. Set the operating pressure.
Turn the Pressure control to obtain the desired operating pressure as shown
on the control panel pressure gage for both grips.
5. If you exceed the desired pressure, perform one of the following:
• For the Model 685.22 Hydraulic Grip Supply, turn the Pressure control
counterclockwise 1/2 turn, and then return to Step 4.
• For the Model 685.10 and Model 685.60 Hydraulic Grip Supplies, turn
the Pressure control counterclockwise 1/2 turn, and cycle the grip
controls by clamping and unclamping the grip. Then return to Step 4.
About Rate Control
The Rate control may be adjusted at any time. If the grips move too fast to suit
your personal preference, turn the Rate control clockwise to slow the speed of
grip action. Turning the Rate control counterclockwise speeds up grip action.
Turning the Rate control fully clockwise stops the flow of fluid to the grips. If
the grips do not operate, check to be sure that the Rate control has not been
turned fully clockwise.
Adjustment of rate is a matter of personal preference. It should be based on the
desired speed of grip action during the gripping and ungripping processes. (The
speed of grip action is dependent both on the adjustment of the rate control and
the particular grips being used.)
When first operating the grips, use a slower speed (lower rate setting). Then
increase the operating speed to your satisfaction.
Important Different grips require different clamp and unclamp rates; be sure
to adjust the Rate control whenever you change grips.