MTS Model 286-20 Confining Pressure Intensifier - Manual (Page 42)

286.20 Pressure Intensifier 42
Operating Procedures
Operation
Emptying the Triaxial Cell
Temperature of fluid in the triaxial cell may exceed the temperature rating of
the Confining Pressure Intensifier.
This could damage the Confining Pressure Intensifier
Always allow fluid in the triaxial cell to cool to 167 ∞F (75∞C) or less before
emptying the triaxial cell back to the reservoir of the Confining Pressure
Intensifier.
Procedure:
1. Verify that the triaxial cell has cooled to 167°F (75°C) or less.
2. Make sure the Air Direction valve is in position “A”.
3. Adjust the electronic controller equipment to reduce pressure in the triaxial
cell to a small, but positive, pressure (e.g., 10 psi).
4. Open the Confining Fluid Output valve one turn.
The pressure intensifier will extend to the end of its stroke as fluid is expelled
from the pressure intensifier, up through the triaxial cell and into the reservoir.
Leave hydraulic power applied to the CPI, with the pressure intensifier fully
extended.
5. Open the Reservoir Fill valve one turn only.
Note Be prepared to perform step 8 and 9 immediately after step 7, in order to
avoid frothing and overflow of fluid from the reservoir.
6. Turn the Air Direction valve to the “B” position.
Compressed air applied to the top of the cell will cause fluid to flow from the
cell, up through the Reservoir Fill valve and into the reservoir.
7. When the reservoir is about half full, turn the Air Direction valve to the
neutral or off position (valve handle pointing straight up.)
Remaining air pressure in the cell will continue to empty the cell.
8. Watch for the first air bubbles to enter the reservoir (from the bottom) and,
when bubbles are seen, immediately turn the Reservoir Fill valve off to
avoid frothing and overflow of fluid from the reservoir.
9. Bleed any remaining air pressure from the cell by turning the Air Direction
valve to the “A” position.
CAUTION