Rotary valves are built to take lots of punishment, but there are certain things you shouldn’t do with them. For example, you shouldn’t take your valve skydiving. You shouldn’t feed your valve a margarita. And you shouldn’t make your valve the star of a romantic film because it just can’t handle heartbreak.
When it comes to workplace safety, there are several other (probably more important) rules to keep in mind with your rotary valves. Here are our top six.
Tip #1: Lock out, tag out, rock on
The lockout/tagout procedure is one of the most important aspects of valve safety, because it prevents the release of electricity and other hazardous energy while operators service the valve. The procedure essentially eliminates every danger we’ll cover here — including electric shock, shear points and pinch points — and then some.
Locking out and tagging means powering down your equipment, shutting off all related electrical sources and making a record of your actions. Because rotary valves are often controlled by an automated system, the process also keeps the valve from starting up without warning.
Lockout/tagout is covered under several subsections of OSHA 29 Part 1910.
Tip #2: Keep your fingers out
In your rotary airlock, places where the rotor and housing meet are called shear points. Things like proper lockout/tagout, warning labels and general awareness can keep your staff from getting injured in this way.
We know you’re smart enough not to stick your fingers in a moving airlock. Right?
But accidents happen, and there is a surefire way to prevent you and your employees from losing any digits: inlet and outlet flange guards.
Flange guards block access to the dangerous moving parts, even if someone has the bright idea to clean the valve while it’s still rotating. These accessories are mandatory — you should always keep them installed while the valve is being operated.
Tip #3: No, seriously, watch your fingers
We’re not trying to scare you, but shear points aren’t the only danger in a rotary airlock situation: pinch points and exposed rotating shafts also pose a risk.
Pinch points live in areas where the drive chain and sprocket engage. Exposed shafts come up at the seal access area and tail shaft. To prevent contact with any of these moving parts, look into some of the optional guards you can attach to your valve, like tail shaft guards.
Beyond that, always follow the proper lockout/tagout process before working with the equipment.
Tip #4: Avoid high-pressure situations
When you’re working with a pressurized system, higher air pressure is another big hazard to keep on your radar. The sudden release of pressure will blow material through the opening at your personnel, creating a risk of injury. Make sure your operators always relieve process pressure from the valve before opening it for maintenance.
Tip #5: Stay grounded
To avoid potential electrical hazards, your conveying system should generally be grounded with copper wire. This is particularly important if you’re conveying materials that create more static electricity, like plastic pellets.
Grounding your system reduces the risk of electric shock when your workers touch the equipment. It also cuts off a potential ignition source for combustible dust hazards. Static electricity can ignite combustible dust and spark a dangerous explosion in your facility.
For the same reason, it’s important to keep your equipment clean, including the valve interiors and exteriors. That includes checking your outboard bearings to make sure no dust is escaping.
Tip #6: Check yourself before you wreck yourself
Whenever you’re performing maintenance on a valve — or your conveying equipment in general — it’s very important to consistently document your maintenance checks. Keeping a thorough log of your maintenance history will prevent miscommunication down the line, letting future operators know how recently the valve and other equipment has been cleaned, repaired or replaced.
When in Doubt, Ask an Expert
Every rotary valve should be tested extensively, both for quality and for safety. If you have any questions about valve safety, or if you would like more information about optional safety features, you only need to ask.
Megan Thompson is president & COO of ACS Valves (Caledonia, ON, Canada). For more information, call 905-765-2004 or visit www.acsvalve.com.
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