Instruction Manual for OFITE 120-20-A Automated Curing Chamber

Quick guide from the manual

The OFITE 120-20-A Automated Curing Chamber is designed for preparing cement specimens for compressive strength tests under downhole temperatures and pressures. Key operations include preparing cement molds, setting test profiles via the touch screen, and performing routine maintenance on filters and valves.

Setup

1. Remove the instrument from the crate and ensure the PRESSURE RELEASE valve is closed (clockwise).

2. Connect compressed air or Nitrogen, water supply, and drain lines (all 1/4" NPT) to the back of the unit.

3. Connect to a 220V power source. A backup power port is available for an Uninterruptable Power Supply (UPS) to keep electronics active during power loss.

4. Turn the MAIN POWER switch ON.

Operation

Starting a Test:

• Loosen the twelve set screws on the cell cap and remove it.
• Place the prepared cement mold into the cell, ensuring the thermocouple port is centered.
• Lubricate the sealing ring and threads with high-temperature grease.
• Tighten the cell cap by hand, then tighten the twelve set screws in a cross pattern using a torque wrench (first to 90 inch-pounds, then to 180 inch-pounds).
• Insert the thermocouple, set the FILL/DRAIN switch to FILL, and wait for water to flow from the thermocouple connection before tightening the fitting.
• Set HEAT, COOL, and PUMP switches to AUTO and start the test via the display.

Ending a Test:

• If the 'Stop At End' option is off, touch 'Stop Test', set HEAT to OFF, and COOL to ON.
• Once the temperature is below 180°F (80°C), set the PUMP to OFF.
• Slowly open the PRESSURE RELEASE valve (counterclockwise) only after the temperature is below 200°F (93°C).
• Set FILL/DRAIN to DRAIN to purge water, then remove the specimens.

Onboard Display

The touch screen allows for test configuration, manual control, and data archiving. Use the 'Test Setup' screen to create ramp, step, or dwell profiles. The 'Utilities' screen allows configuration of units (°F/°C, psi/MPa) and the 'Stop At End' feature. Data and calibrations can be exported to a FAT32-formatted USB drive via the 'Archive' screen.

Maintenance

• Water Filter: Clean every three months (or more frequently depending on water quality).
• Air Filter: Periodically empty accumulated moisture from the clear chamber.
• Outlet Filter: Clean monthly to remove cement residue.
• Check Valve: Clean or replace if dirty to ensure proper air/water flow.
• Regulators: Main pump regulator should be 80-100 psi; back pressure regulator should be 70-80 psi.