5 Rotary Valve Safety Reminders Critical for NFPA 69

Gus Carrington

Gus Carrington About The Author

Oct 13, 2021

Rotary valves perform a critical function that some manufacturers may forget is within the range of these mechanical components. In the unfortunate and dangerous circumstance that fire ignites in a facility and then flows through a system, it could actually be a rotary valve that isolates and contains the dangerous flames.

As we’re sure that you are aware, the National Fire Protection Association (NFPA) creates and publishes standards for all manner of equipment in order to assist manufacturers in the practice of plant safety. This helps companies be best prepared for Authorities Having Jurisdiction (AHJs) to inspect and approve of a safe environment. Specifically, NFPA 69 relates to rotary valves and there are certainly consequences a manufacturer could potentially face if their rotary valves don’t meet the helpful standards found within. 

Each plant has different levels of production. Each worker at a plant may already think they know what’s best based on years of experience in that specific facility. Still, OSHA will be quick to fine a company whose facility experienced a costly incident because their valves were not in line with NFPA guidelines. The saving grace of not just your bottom line, but more importantly, your employees’ safety could very well depend on a single valve. Do you want to take that chance?  

Even if you do ensure that a new valve is up to NFPA guidelines, that same valve can actually deteriorate over time. In this AZO blog post, we’ll share five points to routinely inspect in regards to your rotary valves that could truly make the difference when it comes to fire safety in your facility.

Abrasive materials wear down valves over time

If you are handling particularly abrasive material, it is incumbent on you to check your valves as well as other equipment. Materials like sand, sugar or diatomaceous earth can slowly but surely wear away at valves and their clearances as time goes on. Some manufacturers don’t realize that a rotary valve breaking down can shut down an entire process. It is a helpful strategy for any company handling abrasive material to regularly check their valves for this kind of wear.

Temperature also affects rotary valves over time

When shopping for new valves, it is always important to fill out any questionnaires accurately. If, for example, you miscommunicate the temperature of your facility by about 50 degrees, the estimated effect on a rotary valve could be incredibly misinterpreted. 

The simple truth is that heat expands metal. If a rotor were to continue to turn (after expanding), it could potentially grind or contact the housing and end covers. Severe damage could be inflicted as a result. Replacing a rotary valve after such an event would be necessary, which brings us to our next point:  

Owning multiple valves is responsible preventative maintenance

Simply put, when (not if) shutdown occurs, having a backup valve ready to go can make or break productivity. In the end, it can certainly be less expensive to buy two rotary valves on the front end than the cost of lost production when waiting weeks for a second valve. 

An effective solutions provider can fix a valve (and save replacement costs)

The right solutions provider can inspect valves and determine what needs to be done in order to return the same valve back to meeting NFPA guidelines. AZO believes DMN-WESTINGHOUSE offers the best valves on the market, and we like to think of a pneumatic conveying system as a chain (only as strong as its weakest link).

Most of the time, the links (valves) don’t need to be completely replaced, according to DMN sales manager Chris Williams. There is still a cost associated with refurbishing a rotary valve, but it generally pales in comparison to buying and installing a new valve. A trusted partner to AZO, DMN actually doesn’t just think of itself as a valve manufacturer. All in all, they’re a dependable solutions provider with more than 45 years of experience. 

“We’ve seen a lot and done a lot,” Williams said. ”We’ve seen an awful lot of applications and we’ve got an awful lot of different executions.”

 

Safety liabilities should be monitored effectively with valves

Finally, it is of the utmost importance for any manufacturer to take stock of the hazards that any of their machines unfortunately present. Though rotary valves contain the ability to stop a fire in its tracks, the rotating blades of the valve do present a threat to an operator's hand and arms if not handled with care. When cleaning the valve, for example, operators must carefully watch the moving parts and they must be turned off before cleaning. 

The motors of a valve also can present safety concerns. Chain-driven motors with moving parts present a liability, so some professionals recommend and encourage direct drives. Manufacturers also need to ensure that the correct motors are in the correct area according to class/division specifications. This will come into play when dust becomes a concern and if there is a wash-down happening in the same area. 

If you’d like to hear more about ingredient automation as a whole, never hesitate to contact AZO. We have a multitude of sales associates who have spent decades finding the right choices for pneumatic conveying, bulk bag unloading and more. Our partner DMN-WESTINGHOUSE offers tailor-made solutions to the global food, dairy, plastics, (Petro)chemical, pharmaceutical, mineral, power and biomass industries. 

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