The ZPB-201 pneumatic lock-up valve is a critical safety auxiliary device within industrial automation control systems. Primarily installed in the control loops of pneumatic actuators, it serves to monitor the instrument air supply pressure in real-time. The core operating principle involves a balance between internal spring tension and air supply pressure. Should the air supply fall below a pre-calculated lock-up value (set point) due to failure, the valve rapidly switches its internal air circuits to trap the air pressure within the actuator chambers. This ensures the control valve remains "locked" at its last position prior to air failure. The ZPB-201 features sensitive response, reliable positioning, and adjustable switching pressure, making it essential for maintaining process stability in the petroleum, chemical, and power industries during sudden air supply loss.

Product Image of ZPB-201 Pneumatic Lock-up Valve

1.High-sensitivity real-time monitoring:Combines high-quality pressure-sensing diaphragms with precision springs to detect minute air supply fluctuations. Lock-up actions are triggered instantly at the critical set point to ensure timely fail-safe positioning.
2.Wide-range adjustment of switching pressure:Equipped with an external adjustment bolt, allowing users to freely set the lock-up pressure within a broad range based on process safety needs. The adjustment process is linear with minimal set-point drift.
3.Superior sealing and retention capability:Core air circuit switching parts utilize wear-resistant soft-sealing materials to ensure trapped pressure in the actuator remains constant for extended periods, effectively preventing valve drift.
4.Compact structure and flexible mounting:Features small dimensions and a lightweight design. It can be directly installed on pneumatic lines or mounted to the actuator side via brackets, ideal for compact valve assembly layouts.
5.Low flow resistance and high efficiency:Internally optimized air channels ensure minimal resistance to control signals during normal operation, maintaining the response speed of the primary control loop.
6.Durable housing and protection:The die-cast aluminum alloy or stainless steel casing with anti-corrosion coating provides excellent vibration resistance and all-weather protection, adapting to harsh outdoor industrial environments.
7.Intrinsically safe without spark risks:Operates entirely on compressed air without electrical components, providing natural explosion-proof safety for use in high-risk hazardous areas.
8.Easy maintenance and long service life:Minimal moving parts result in low mechanical wear. The modular design allows for straightforward filter cleaning and seal inspections, ensuring low overall maintenance costs.

Main Technical Parameters

Ambient Conditions: Temperature: -20 to +60℃; Relative Humidity: ≤95%

Environmental Vibration: Vibration Frequency: ≤25Hz; Amplitude: <0.2mm

Set Pressure Adjustment Range: 0.8–2.5 kgf/cm²

Channel Pressure: 0.2–2 kgf/cm²

Sensitivity: ≤0.15 kgf/cm²

Channel Flow Rate: ≥1.5 m³/h