MTS Model 286-30 Pore Pressure Intensifier - Manual (Page 40)

286.30 Pressure Intensifier 40
Operating Procedures
Operation
Pressurizing and Depressurizing the Pore Fluid
Purpose of this
procedure:
This procedure describes how and when:
A. to pressurize the pore fluid.
B. to heat and cool the triaxial cell, if required.
C. to depressurize the pore fluid at the end of the test.
Preliminary steps or
conditions:
The pore pressure intensifier system should be in the same condition as existed
after performing
“Filling the Specimen’s Pores with Pore Fluid” on page 35.”
• A jacketed specimen is installed in the triaxial cell and the cell is sealed and
ready for operation.
• High hydraulic pressure is turned on and the PPI is being controlled by the
external controller equipment operating in pressure control mode.
• The Intensifier Fill, Reservoir Return, Reservoir Drain/Fill and the Pore
Pressure Output valves are all closed.
• The Pore Pressure Input valve is open.
Note If any of these conditions are not met, perform “Filling the Reservoir” on
page 30 as necessary.
Pore fluid pressure should not be higher than confining fluid pressure.
If pore fluid pressure is higher than confining fluid pressure, the jacket on
the specimen will rupture.
Always maintain confining fluid pressure at a higher level than pore fluid pressure.
(Refer to the manual for the Confining Pressure Intensifier for instructions on
controlling confining pressure.)
CAUTION