The HE-LO 3/2-way valves are manually operated on-off valves (bistable) for the targeted exhausting of pneumatic systems.
The valve is installed in air supply lines and meets the requirements of OSHA 29 CFR 147 "Control of Hazardous Energy" of the US Department of Labor.
By pressing the operating knob, the passage from 1 to 2 is blocked and from 2 to 3 is opened. The maximum exhausting flow is achieved by keeping the control knob in the end position until the downstream system is completely exhausted. When blocked, the valve can be locked by means of a padlock.
This ensures that a shut down system (e.g. during maintenance work) cannot be supplied with air without authorization.
The PVEL 3/2-way valves are manually (PVEL-H) or pneumatically (PVEL-P) operated shut off valves (bistable) for the targeted pressurization and exhausting of pneumatic systems up to 50 bar.
The PVEL-H has a latching intermediate position which enables slow pressurization (soft-start function) of the system. A mark on the top cover indicates the position of the Soft Start rotary knob. When blocked, the PVEL-H can be locked with up to four padlocks.
The PVEL-P is switched by an external pneumatic signal and has a throttling point inside. A slow switch-on can be achieved by throttling the control pressure build-up.