I can’t say I’m 100% sure on how these rotating gate valve lockouts from Master Lock are intended to be used, but I’m guessing one possible use is to prevent somebody from turning the water — especially if it’s heated to steam — back on when you’re working on a plumbing project across the building. If lock-out tag-out works for electricians, why not for plumbers?
When locked, the valve lockout surrounds the handle and freely rotates about it so you can’t turn it. You can also knock out the center for rising stem gate valves — in other words, if the center sticks out farther than the lockout. There’s room for multiple locks, in case more than one person is working on a branch and you need clearance from each person before turning the valve back on.
Made from Xenoy thermoplastic which is tough, lightweight, and chemical resistant, the lockout will operate in temperatures from -50°F to 350°F. Master Lock sells five different sizes that fit 1″ to 3″ diameter handles, 2″ to 5″ handles, 4″ to 6-1/2″, 6″ to 10″ handles, and 8″ to 13″ handles.
You can buy the valve lockouts singly starting at $11 to $28 depending on size, or buy a set with all five sizes which nest neatly into each other for around $100.