The YT-3400L / YT-3450L is a digital electro-pneumatic positioner for linear pneumatic actuators, supporting both single and double acting types. It accepts a 4–20 mA DC input signal and modulates actuator air supply to ensure valve travel matches the controller setpoint. Features include auto calibration, PID control, alarm functions, and HART communication.
The order sheet distinguishes YT-3400 with aluminum die-cast housing and YT-3450 with Stainless Steel 316 housing. SS316 is selected for corrosive environments, outdoor installations, or frequent washdown areas.
Supported characteristics: linear, quick open, equal percentage, and user-defined 16-point. Split range 4–12 mA / 12–20 mA, tight shut-close / shut-open, A/M switch, and variable orifice are used to minimize hunting and optimize response for small actuators or valves with high stem friction.
Used on control valves for steam, condensate, hot water, chilled water, instrument air, and process utility networks. Typical installations: heat exchangers, bypass lines, manifolds, and flow/pressure/temperature control loops.
When is YT-3450L selected?
When SS316 housing is required instead of aluminum.
What should be checked before selection?
Stroke, fail action, air supply pressure, Ex classification, HART, 4–20 mA feedback, limit switches, and PT/NPT connection type.
YT-3400(YT-3450) Smart Valve Positioner accurately controls valve stroke, according to input signal of 4-20mA, which is being input from the controller. In addition, built-in micro-processing operator optimizes the positioner's performance and provides unique functions such as Auto calibration, PID control, Alarm, and Hart protocol.
Accessories & Compatibility
