OSHA once again clarifies that locking out the air source to a pneumatically powered control valve is NOT locking the energy isolation device!
When I taught at ASSP Seminarfest several years ago, the most disputed point was this very practice. I was very clear, which did not sit well with some attendees, that locking the air hoses to these valves was in NO WAY complaint – much less safe. I even pointed out how the idea that locking the end of the hose was so badly flawed as anyone could still get another air hose and plug it in, and they would NOT have violated LOTO – so at least lockout the valve’s hose fitting and not the end of the hose. But OSHA has been obvious for nearly my entire 30 years in safety – this is NOT a permitted practice.
But the reason why OSHA states are just sad!
They do not point out that locking out the airline going to the pneumatically powered control valve is fundamentally flawed, as the air to the valve is NOT the form of hazardous energy the worker is potentially exposed to. In the scenario provided, working on a pump, the LOCKOUT devices must be placed on the UPSTREAM and DOWNSTREAM isolation valves to isolate the pump from the hazardous chemical safely.
Now, suppose the work was actually on the pneumatically powered control valve(s). In that case, the air supply is an energy source that must be isolated as that is the energy source that operates the valve.
Here is the full OSHA document…