Humboldt HM-4160 FlexPanels - Manual (Page 23)

Back Pressure Saturate Sample
The following steps should be followed to back pressure saturate the sample.
1) Turn the Selection Valve (A2) to Pressure.
2) Turn the Bias Valve to Bias On.
3) Turn the Burette Valve (V2) to Burette.
4) Turn the Selection Valve (A3) to off.
5) Turn the Bridge Valve (BV) to Bridge On.
6) Turn the Burette Valve (V3) to Burette.
7) Make sure the Top and Base Valves on the Triaxial cell, which are connected
to the FlexPanel, are open. Check the cell pressure by lifting the Toggle
Valve (T1).
8) Check the level of the water in the Burettes in Section 2 (Base) and 3 (Top)
to make sure they are over half full.
9) Apply back pressure to Sample.
a) Take Pore Pressure reading and Burette readings for Section 2 (Base)
and 3 (Top).
b) Lift to open Toggle Valve (T2) in Section 2.
c) Adjust the back pressure using Regulator (R2). Raise the pressure to
5 psi (35 kpa). When the pressure is increased, check the sample and burette
to make sure the Membrane is not blowing up. If water from the Burettes in
Section 2 (Base) and 3 (Top) start filling the membrane, close the Top and
Base Valves on the Triaxial Cell and check pressure in Section 1 (Cell) to
make sure it has increased. The pressure can be read on the Digital Display
on the Control Panel.
d) Check cell pressure by lifting Toggle Valve (T1) in section 1 and read the
pressure on the Digital Display on the control panel. The cell pressure
should have increased by 5 psi (35 kpa). If the pressure did not increase by
5 psi (35 kpa)
adjust the Pressure Regulator (R1) to the appropriate reading.
The following steps should be followed to check B valve during back pressure
saturation.
1) Check the back pressure, lift Toggle Valve (T2) in section 2 (Base). Make
adjustments in reading if necessary.
2) Check the cell pressure, lift Toggle Valve (T1) in section 1 (Cell) and make
adjustment in reading if necessary.
3) Close the Top and Base Drainage Valves on the base of the Triaxial Cell.
4) Take Pore Pressure Transducer reading. The pore pressure transducer is
part of the Triaxial cell when we do the triaxial cell manual will address the pore
pressure transducer.