The PowerHalt PH5 is an electronically controlled diesel engine emergency shutdown valve engineered to instantly stop a runaway engine by blocking its air intake path. Available as a standalone base valve for custom kit integration, it supports nine bore sizes from 1.75 to 5.0 inches. Designed for Class 6–8 commercial trucks, off-highway equipment, and stationary diesel applications where space, reliability, and regulatory compliance are critical.
The PowerHalt PH5 is a positive air intake shut-off valve engineered to deliver reliable emergency engine shutdown for diesel-powered equipment. Supplied here as a base valve for custom kit configurations, it gives engineers and system integrators the flexibility to specify their own controller, wiring harness, and mounting hardware. The valve installs directly into the air intake hose and remains fully open during normal operation. When an overspeed condition is detected — or when an operator triggers a manual shutdown — the electronically controlled butterfly valve plate closes instantly, cutting off combustion air and forcing the engine to a safe stop. Available in bore sizes from 1.75 inches to 5.0 inches, in both 12 VDC and 24 VDC configurations, the PH5 is suited to a broad range of heavy-duty commercial, industrial, and marine diesel engine applications.
The PowerHalt PH5 base valve combines a rugged mechanical design with flexible electronic control, delivering dependable diesel engine emergency shutdown across the most demanding industrial and commercial environments.
Key performance and dimensional data for the PowerHalt PH5 base valve. Nine bore sizes are available to match your engine's air intake configuration. Specifications are subject to revision; always confirm with the current datasheet before finalising a design.
| Parameter | Specification |
|---|---|
| Product Series | PowerHalt PH5 |
| Valve Operation | Electronically Controlled, Spring Return Butterfly Valve |
| Resting Position | Valve Open (Normal Engine Operation) |
| Activated Position | Valve Closed (Engine Shutdown) |
| Hose Bore Sizes (A) | 44.5 mm / 51 mm / 57 mm / 64 mm / 70 mm / 76 mm / 89 mm / 102 mm / 127 mm (1.75" – 5.0") |
| Valve Bore Sizes (B) | 35.5 mm to 118 mm (1.40" to 4.65") corresponding to hose sizes above |
| Mounting Flange Type | Hose-to-Hose, Standard Mounting Flanges |
| Pipe Size Range Supported | Ø38 mm to Ø140 mm (Ø1.5 in to Ø5.5 in) |
| Max Intake Boost Air Pressure | 3.45 bar gauge (50 psig) |
| Continuous Intake Air Temperature | -55°C to +175°C (-67°F to +347°F) |
| Ambient Operating Temperature | -40°C to +120°C (-40°F to +248°F) |
| Ingress Protection Rating | IP67 |
| Vibration Rating | 18.6 G_RMS (7.7 G_RMS for 5.0" bore) |
| Fatigue Cycle Design Life | Designed for 100,000+ cycles; validated to 10,000 cycles |
| Corrosion Resistance | ASTM B117 — 96-hour Salt Fog Tested |
| Valve Housing Material | Aluminum Flap and Housing |
| Voltage Compatibility | 12 VDC / 24 VDC (nominal) |
| Controller Voltage | 12 / 24 VDC nominal (PowerGuard Controller) |
| Maximum Relay Rating | 20 A @ 28 VDC |
| Power Consumption | 30 mA maximum continuous (nominal) |
| Controller Housing Compliance | SAE J1455 (-40°C to +85°C) |
| Standard Compliance | CSA B621-14 & B622-14 |
| Weight (1.75" / 2.0" / 2.25") | 1.49 kg / 1.47 kg / 1.45 kg (3.3 / 3.2 / 3.2 lbs) |
| Weight (2.5" / 2.75" / 3.0") | 1.64 kg / 1.62 kg / 1.59 kg (3.6 / 3.6 / 3.5 lbs) |
| Weight (3.5" / 4.0" / 5.0") | 1.88 kg / 1.79 kg / 2.17 kg (4.1 / 3.9 / 4.8 lbs) |
| Install Manual Reference | L6447 / L6448 |
The PowerHalt PH5 is installed directly into the diesel engine's air intake hose using standard hose-to-hose mounting flanges. In normal operation, the butterfly valve plate sits fully open inside the air path, placing zero restriction on airflow to the engine. When configured with the PowerGuard Automatic Controller, a gear tooth sensor mounted to the transmission bell housing continuously reads engine RPM. If the measured speed climbs above the user-programmed trip point — a condition typically caused by the engine ingesting external fuel sources such as crankcase oil vapors or flammable gas — the controller immediately energises the valve actuator. The actuator rotates the aluminum butterfly plate 90 degrees, seating it firmly against the valve bore and blocking all incoming combustion air. With no air reaching the cylinders, combustion stops and the engine comes to a halt. After shutdown, the system can be configured to hold the valve closed until manually reset by a qualified operator, or to automatically return to the open position once the fault condition clears. An optional valve position switch provides a confirmation signal to panel indicator lights or remote monitoring systems, ensuring operators have real-time visibility of valve status throughout the process.
The PH5 base valve is the core shut-off valve component supplied without a pre-bundled wiring harness or controller. It is intended for engineers and system integrators building custom emergency shutdown systems, allowing them to select and pair their own preferred control hardware, speed sensing method, and wiring configuration around the valve.
The PH5 is available in nine hose bore sizes: 1.75", 2.0", 2.25", 2.5", 2.75", 3.0", 3.5", 4.0", and 5.0" (44.5 mm to 127 mm). Each size is offered in both 12 VDC and 24 VDC variants and in either automatic (PowerGuard) or manual control configurations, giving you 24 kit number options across the full range.
Yes. The PH5 complies with CSA B621-14 and B622-14, which are the relevant standards for air intake shut-off devices on diesel engines in potentially explosive atmospheres, including oil and gas processing facilities, refineries, and underground mines. Always verify that your complete installation meets local regulatory requirements.
Yes. The PH5 is rated for 18.6 G_RMS vibration across the 1.75" to 4.0" bore sizes (7.7 G_RMS for the 5" bore). It is also designed to endure over 100,000 operational cycles. These ratings make it a reliable choice for high-vibration applications such as drilling rigs, underground loaders, and frac trucks.
The PH5 can be paired with the PowerGuard Automatic Controller, which uses a programmable trip speed and a gear tooth RPM sensor to trigger automatic shutdown on overspeed. A manual-only configuration is also available, where valve activation is initiated entirely by an operator switch or an external control input — suitable for applications where automatic engine speed sensing is not required.
Yes. The aluminum valve housing has been validated to ASTM B117 standards (96-hour salt fog test), and the IP67 enclosure rating provides full protection against dust and temporary water submersion. These characteristics make the PH5 a proven choice for work boats, barges, and other marine applications where exposure to moisture and salt air is constant.
Our engineers will confirm the correct PH5 base valve bore size, voltage option, and control configuration for your specific engine and application. Whether you are building a custom emergency shutdown kit for a single asset or specifying across a fleet, we provide full technical documentation and a competitive quote tailored to your requirements and operating environment.
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