The Masoneilan 12800 is a pneumatic level controller that uses the torque-tube displacer principle to measure and control liquid level in process vessels. It combines the proven 12400 transmitter mechanics with a pneumatic controller to provide direct on/off or proportional control without electricity. It's widely used in refineries and chemical plants where pneumatic systems are preferred for safety or simplicity.

• Torque-tube displacer design – no process seals
• Pneumatic output for direct valve control
• Adjustable proportional band and reset
• Local setpoint adjustment
• Wide range of displacer materials
• High pressure/temperature capability
• Simple, no-electronic design

• Measurement Range: 356 mm to 3048 mm (14" to 120")
• Process Pressure: Up to ANSI Class 2500 / PN 400
• Process Temperature: -196 °C to +400 °C
• Output Signal: 0.2–1.0 bar (3–15 psig) pneumatic
• Supply Pressure: Typically 1.4–6.9 bar (20–100 psig)
• Materials: Carbon steel, 316L stainless steel, Hastelloy C, Monel
• Controller Action: Direct or reverse

• Boiler drum level control
• Separator level control
• High-pressure vessel level
• Interface control in refineries

• 12400 series smart transmitter
• 12410 external cage version
• Pneumatic control valves