MTS Model 286-20 Confining Pressure Intensifier - Manual (Page 34)

286.20 Pressure Intensifier 34
Operating Procedures
Operation
Filling the Triaxial Cell
Note Before starting this procedure, decide whether the triaxial cell (or
pressure vessel) will be filled from the reservoir or from an external fluid
container. See Heading 2.5.5. Normal operating procedure when
operating with an MTS triaxial cell, is to fill the triaxial cell from the CPI’s
fluid reservoir.
Preliminary step A. If you are filling the triaxial cell from an external container, connect a
filler hose between the connector on the lower side of the Fluid
Direction valve (rear side of control panel) and the external fluid
container. Immerse the container end of the hose in the fluid.
Procedure
1. Set the Fluid Direction valve to the desired source of confining fluid:
• Position “A” selects fluid from the reservoir.
• Position “C” selects fluid from the external container.
2. Turn the Reservoir Fill valve fully clockwise to Close.
3. Turn the Intensifier Fill valve fully clockwise to Close.
4. Turn the Confining Fluid Input valve a turn or two counterclockwise to
Open.
5. Turn the Confining Fluid Output valve a turn or two counterclockwise to
Open.
6. Open the confining fluid valve on the triaxial cell. See the lower sketch in
the following figure. (The CPI’s Confining Fluid Input valve is connected
by high pressure hose to the triaxial cells lower confining fluid valve. The
CPI’s Confining Fluid Output valve is connected to the triaxial cell’s
pressure relief valve.)
7. Set the Air Direction valve to position A.
8. Actuate the air-driven hydraulic pump by rotating the Fluid Transfer Pump
Control counterclockwise. Watch the reservoir. Regulate the speed of the
air-driven pump to avoid frothing of the fluid in the reservoir. Excessive
frothing can cause fluid to overflow from the reservoir (on early CPI
versions only).
Note Fluid will flow into the triaxial cell, forcing air out to the reservoir.
On later CPI versions, the line from the Air Direction control expels air/
fluid into the reservoir from above the reservoir’s fluid level -- watch for
bubble-free fluid to flow into the reservoir. On earlier CPI versions the
line from the Air Direction control enters into the bottom of the reservoir -
- watch for the bubble stream to stop flowing.
9. Watch for fluid flow into the reservoir and note any air bubbles. When air
bubbles cease to appear, turn the Fluid Transfer Pump Control to the Off
position.