MTS Series 685 Hydraulic Grip Supply - Manual (Page 15)

Series 685 Grip Supply Functional Description
Series 685 Grip Supply Product Information Introduction 15
Series 685 Grip Supply Functional Description
Series 685 Hydraulic Grip Supplies are designed to provide the hydraulic
pressure and grip control for specimen grips. All of the grip supplies include the
following features:
• Hydraulic flow control determines how fast the grips operate.
• Each grip has an independent pressure control valve. Each model has a
different adjustment range.
• Each of the two grips has an independent grip/release control.
Model 685.10
The Model 685.10 Hydraulic Grip Supply includes a self-contained hydraulic
system. Only electrical power is needed for continuous operation. The hydraulic
pressure can be adjusted between 7 MPa (1000 psi) and adjusted up to the rated
output 70 MPa (10,000 psi).
Model 685.22
The Model 685.22 Hydraulic Grip Supply includes a self-contained hydraulic
system. Only electrical power is needed for continuous operation. The hydraulic
pressure can be adjusted between 0.7 and 20.7 MPa (100 and 3000 psi).
Model 685.60
The Model 685.60 Hydraulic Grip Supply uses the hydraulic power unit (HPU)
installed in your lab. The grip supply is factory rated for 45 MPa (6500 psi) or 68
MPa (10,000 psi). The output pressure can be adjusted up to the rated output.
Hydraulic power unit
The Model 685.10 and Model 685.22 Hydraulic Grip Supplies have a self-
contained hydraulic system. The Model 685.60 Hydraulic Grip Supply gets its
hydraulic pressure from the hydraulic power unit in the lab.
The self-contained units include a reservoir for the hydraulic fluid and a motor
that drives a pump. The pump draws the hydraulic fluid from the reservoir
through a strain filter. The hydraulic fluid is pumped to the pressure manifold
where the pump pressure is regulated. When the hydraulic fluid is returned to the
reservoir, it is run through a cooler and a 10-micron filter.
Supply manifold
The supply manifold includes two pressure reducing valves and a pressure gage.
One of the pressure reducing valves establishes the output pressure of the pump
(each model is set to a different pressure). The other is used as a relief valve that
is set 1.7 MPa (250 psi) higher than the pump’s output pressure. In the event the
output pressure exceeds the relief valve setting, the excess hydraulic pressure is
shunted to the return line. The output is sent to the control manifold.
Control manifold
The control manifold outputs the hydraulic control to the grips. The control
manifold includes all of the front panel controls. All three models use the same
front panel controls.
Intensifier
The Model 685.10 and Model 685.60 Hydraulic Grip Supplies include two oil-to-
oil hydraulic intensifiers. These devices multiply the input pressure by a factor of
four to obtain a higher output pressure.They are located on the control manifold.
Rate control
The Rate control is a needle valve that restricts the hydraulic flow. This
adjustment determines how fast the grips clamp and unclamp.
Important The rate setting will be different for all grip sizes. You should be
sure to change this setting whenever you change grip sizes.