D Automatic Air Shut Off Valve

Product Description

The Chalwyn D Automatic Air Shut Off Valve (SKU Chalwyn-D) is a self-contained, flow-actuated overspeed shutdown valve designed to protect diesel engines from dangerous runaway conditions. Unlike electric or solenoid-operated valves, the Chalwyn D requires no external power source or speed signal—the intake airflow itself provides the closing force.

When engine speed exceeds the pre-set point, the valve automatically closes to shut off intake air. Once the engine stops, it automatically resets to the open position, ready for restart. This simple, reliable design makes the D Series an excellent choice for engine overspeed protection in rugged industrial and offshore environments.

The Model D is the basic automatic version. The D-AM variant adds a manually operated pull “T” handle cable stop (available in cable lengths of 1.0, 1.5, 2.0, and 3.0 meters). Both models are offered in multiple bore sizes and are selected based on the engine power at rated speed and the air intake line bore size.

Key Benefits

• Automatic Engine Overspeed Protection: No electronics required—airflow actuates shutdown.
• Automatic Reset After Engine Stops: Minimizes downtime and simplifies restart.
• Flexible Sizing: Available in multiple bore sizes (D45, D51, D57, D64, D70, D80) to match engine ratings and intake diameters.
• Turbocharged & Naturally Aspirated Engines: Provides reliable protection even with turbocharged engines.
• Simple Installation: Easy to install close to the engine air intake manifold.

Features

• Easy to Install: Lightweight, compact, and fits into existing intake systems.
• No External Power or Speed Signal Required: Reduces complexity and maintenance.
• Air Flow Actuated: Self-contained design eliminates wiring or sensors.
• Automatic Reset After Engine Stops: Ready for immediate restart.
• Manual Override Option (D-AM): With cable stop for manual shutdown.
• Adjustable Overspeed Trip Point: Using the built-in adjuster and locknut (see page 5 of the datasheet for adjustment procedure.).