MTS Model 286-20 Confining Pressure Intensifier - Manual (Page 38)

286.20 Pressure Intensifier 38
Operating Procedures
Operation
Procedure:
1. Configure the confining pressure system’s controller for the displacement
control mode. (The pressure control mode will be used later while
pressurizing the triaxial cell.)
to position the pressure
intensifier’s piston
2. On the triaxial cell, close the lower confining pressure valve. (Leave the
triaxial cell’s upper valve open.)
3. On the CPI, open the Intensifier Fill valve.
4. Make sure the CPI’s Reservoir Fill valve is fully clockwise to the Close
position.
5. At the CPI’s electronic control equipment, turn on low hydraulic pressure.
6. At the CPI’s displacement controller, adjust the position of the pressure
intensifier’s piston for 10% displacement.
Placing the piston at 10% displacement allows a 10% margin for piston
retraction, if required, while still providing a 90% displacement stroke, if
necessary, while pressurizing the triaxial cell.
7. Close the CPI’s Intensifier Fill valve.
High hydraulic pressure will be applied during the following steps.
Conditions that may be hazardous to life and equipment can exist on all
systems or equipment that are connected to the same hydraulic power
source.
Steps 9 and 10 provide some information about how to minimize the hazards of
turning on high hydraulic pressure. However because of the variety of electronic
controller equipment in use, explicit instructions cannot be given here.
pressurizing the
triaxial cell
8. On the electronic control equipment, perform the operations necessary to
switch from displacement control mode to pressure control mode.
With certain types of electronic control equipment, it might be necessary to
turn off hydraulic power while converting to pressure control mode. Other
equipment types allow manual mode switching with hydraulic power on
and, if a computer is included, via the keyboard. Refer to your test controller
documentation.
9. On the triaxial cell, open the lower confining pressure valve.
10. On the CPI, make sure the Confining Fluid Input valve is open.
11. If the triaxial cell is to be heated, set up the temperature controller
equipment as required to bring the triaxial cell to operating temperature.
This process will usually take at least several hours, depending on the
temperature to be reached.
WARNING