OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: 832-320-7300 / Fax: 713-880-9886 / www.ofite.com
15
Operation
Test Procedure
1. Once the cell has reached the required temperature, close the valve
on the hydraulic pump and open the outlet valve. Operate the pump to
increase the pressure in the cell to the desired test pressure to initiate
filtration. Using the pump, maintain the desired differential pressure in the
cell. The differential pressure is the cell pressure less the amount of back
pressure.
Do not exceed 4,000 PSI as the primary or inlet pressure.
2. Set a timer for the desired test times. Filtrate should be collected at a
minimum of 7.5 and 30 minute intervals. Collect and record the total
amount of filtrate and/or mud for 30 minutes. Be sure to maintain the
selected differential pressure and test temperature within ± 5°F (3°C).
3. During filtration collection, the pressure in the cell will tend to decrease,
so it will be necessary to apply additional hydraulic pressure to maintain a
constant pressure.
4. If the back pressure rises during the test, cautiously reduce the pressure
by opening the drain valve on the receiver and drawing off some of the
filtrate into the graduated cylinder. The filtrate will be at or near the test
temperature and slowly opening the drain valve will minimize any spatter-
ing of the fluid and any potential contact with hands and fingers. Bleed
only enough to reduce the back pressure to its initial setting.
5. After the 30 minute time period, close the outlet valve. Open the receiver
drain valve and allow it to blow dry to remove any filtrate and/or mud from
the receiver. Record the total amount of liquid recovered, including the
spurt loss.
6. Turn the T-handle on the air regulator clockwise to stop adding pressure
to the back pressure receiver.
