Airlock interlock multi-doors Interlocks Electronic Interlock for cleanroom

core principle of Airlock interlock

Airlock interlock use physical or logical means to make the opening/closing operations of valves interdependent and mutually restrictive. For example:

●Mechanical interlocks:

Use mechanical components such as levers, chains, or gears to connect the valve stems of two valves. When one valve operates, the mechanical structure forces the other valve to operate synchronously, ensuring the correct operating sequence.

●Electrical interlocks:

Achieve logical control through relays, contactors, or PLCs (Programmable Logic Controllers). For example, when a pressure sensor detects excessive pipeline pressure, the PLC outputs a signal to close the inlet valve and simultaneously open the exhaust valve to prevent system overpressure.

●Pneumatic interlocks:

Use compressed air pressure signals to control valve operation. For example, in pneumatic conveying systems for food processing, pneumatic interlocking devices ensure that materials are conveyed in sequence, preventing blockages or leaks.

core function of Airlock interlock

●Preventing Misoperation

Ensuring valves operate in the predetermined sequence prevents system malfunctions or accidents caused by incorrect operation. For example, in nuclear power equipment maintenance, key interlock devices prevent valves from being opened accidentally.

●Ensuring System Safety

In hazardous conditions (such as high pressure, high temperature, and flammable/explosive environments), interlock devices prevent valves from opening or closing simultaneously, avoiding system overpressure, leakage, or explosion. For example, DBB valves in LNG-fueled ships ensure emergency shut-off.

●Achieving Operation Sequence Control

Enforcing correct operating procedures ensures stable system operation. For example, in steam systems, condensate drain valves automatically open after the inlet valve is closed to prevent water hammer.