A hydraulic lockout valve is used in pneumatic and hydraulic applications to prevent injury during maintenance to machinery. OSHA (Occupational Safety and Health Administration) actually has guidelines that regulate the use of lockout valves for industrial equipment. When more than one person works on a locked-out device, the procedure is called lockout/tagout. A lockout valve utilizes a padlock to insure that the valves are not unlocked during maintenance and repair.

A hydraulic lockout valve is usually colored a bright yellow and red for safety purposes, with the valve being yellow and the valve lever red. The valve is lever-operated and can be put into the open or shut position. Lockout valves are designed for one or more padlocks to be adhered to the valve. This prevents accidents when more than one person is working on a locked-out machine. For a lockout valve with multiple padlocks, each worker will be assigned a padlock. Until each worker removes his padlock from the valve, the machine remains locked out.

When a lockout valve is turned on, air flows freely through the valve and throughout the machines air lines. When the lockout valve is turned off, the air from the main air supply is shut off. Exhaust valves within the machine are then opened, allowing all air pressure within the machine to bleed out. At this time, workers attach their padlocks to the bleeder valve to insure safety.

To operate the on and off position of a lockout valve, a lever is pushed in or pulled out. When the lever is out, the lockout valve is open and allowing the free flow of air. When the lever is pushed in, the lockout valve is off and preventing air flow. Hydraulic lockout valve installation is either inline-mounted or surface-mounted, depending on the application. With either installation the valves must be in a noticeable place with easy access.