Shutoff Valves

There are 3 different activation options for PowerHalt air shut-off valves. Read below to learn more and determine which is best suited for your application.
Pull Cable Activation – The simplest activation method is pull cable activation. This is accomplished via pull cable which is available in lengths from 2-20’ depending on which valve you choose. The PH1 and PH2 air shut-off valves are available with manual activation. The PH2 air shut-off valve is available with a combination of manual and electronic activation as well.

NOTE: Manual activation is only recommended for applications where the operator works in close proximity to the engine.

Electronic Activation – The most common activation method is electronic activation. This is accomplished by supplying DC power to the system which then powers an electronic motor or solenoid depending on your valve choice. The PH2, PH3, and PH5 air shut-off valves are available with electronic activation.

Pneumatic Activation – For systems with on-board air, the pneumatic activation option is available. Pneumatic activation is accomplished by supplying air to an electronic solenoid which is powered by DC power through the control system. The PH2 air shut-off valve is available with pneumatic activation.

Automatic activation valves monitor your engine speed and will automatically activate the valve and shut-down the engine when it detects that the engine has exceeded a user set trip speed. These valves also have a manual override option that allows the operator to activate the valve at any time. PH2, PH3, & PH5 valves are all available as automatic activation valves.

Manual activation valves will activate only when instructed to do so by the operator. Manual activation is achieved by pressing a button / pushing a toggle switch / pulling a pull cable depending on which valve you have chosen. All PowerHalt valves are available as manual activation only valves.

Manual activation valves are recommended for applications where the operator works in close proximity to the valve. In all other cases, Pacbrake recommends choosing an automatic activation valve. Certain government and internal company regulations will also indicate if you are required to have an automatic or manual activation valve.

Electronic reset valves are able to reset themselves to the open position after closing. PH3 valves are able to electronically reset themselves.

Manual reset valves require that the operator access the valve and manually turn the reset knob on the valve to reset it to the open position after closing. PH1, PH2, & PH5 valves require the operator to manually reset them.

Large V-engines may require two or more air shut-off valves. The automatic reset option is recommended to prevent incidents where only one valve is reopened after a shut down, preventing engine damage.

The PowerHalt PH3 series of air shut-off valves can incorporate multiple auxiliary inputs from external sources for activation of the air shut-off valve in the event of an emergency. Ideal for secondary emergency monitoring systems as well as multiple locations for manual override input.

To comply with CSA B621-14 and B622-14 a intake shut-off valve must have the capability to automatically (without user intervention) shut down an over speeding engine, as well as remain shut until a user commands it open (requires user intervention to open after closing). PH2, PH3 and PH5 valves equip ed with PowerGuard (automatic shut-down based on a user programmed engine speed) will comply with both standard subsections.