The Marsh Bellofram T2000 series is a hazardous-area electro-pneumatic pressure controller that converts an electrical control signal (4–20 mA or 0–10 VDC) into a precise pneumatic output pressure using a patented hermetically sealed piezoceramic actuator. Unlike conventional I/P transducers that rely on a voice-coil and flapper-nozzle mechanism — which drifts with temperature, vibration, and mounting orientation — the T2000's solid-state piezoceramic dimorph is inherently immune to these effects, delivering ±0.1% full-scale typical accuracy with no supply pressure or supply voltage effect.

How does the piezoceramic actuator improve reliability?

Conventional I/P transducers use a moving-coil motor driving a flapper against a nozzle orifice — a precision mechanical assembly that is sensitive to contamination, mounting orientation, and mechanical shock. The T2000 replaces this with a hermetically sealed piezoceramic bending element: applying the control signal deforms the ceramic, which directly modulates the pilot pressure to the integral volume booster. With no orifices to clog, no coil to burn out, and no moving iron components to fatigue, the actuator maintains calibration through extreme vibration (<1% FS at ±1G, 5–1000 Hz), temperature swings (0.02% FS/°F from -40° to 180°F), and arbitrary mounting positions. The sealed electronics compartment — rated IP66/NEMA 4X on conduit and Hirschmann connector models — isolates the actuator and control circuitry from humid, oil-laden, and corrosive process environments.

Which pressure range and certification option fits the application?

The T2000 covers eight standard output ranges from 0–2 PSIG (0–0.1 BAR) to 0–120 PSIG (0–8.3 BAR), with split-ranging and direct/reverse action configurable via internal DIP switches. Two certification paths are available:

• T2000 S (Intrinsically Safe): ATEX II 1 G EEx ia IIC T4, FM Class I/II/III Division 1 & 2 Groups A–G, CE-marked. Suited for general hazardous-area service where the control loop is protected by an IS barrier.
• T2000 E (Explosion-Proof): CSA Class I Division 1 Groups C & D, T3; Exia IIB. Rated for natural gas media and applications requiring a flameproof enclosure rather than an IS barrier on the loop.

Common applications include valve positioner and louver control, web tensioning, process control in refineries and chemical plants, and anywhere a pneumatic actuator must be driven from a safe-area or hazardous-area electrical control signal.