On a flotation unit, what maintenance action should be performed on check valves and control valves to prevent failure?

• A. cleaned to prevent failure
• B. replaced on schedule
• C. lubricated
• D. inspected only

Answer: (A)

The main idea is that preventive valve maintenance in a flotation unit hinges on keeping valve passages and seating surfaces free of debris and deposits. When check valves and control valves accumulate dirt, scale, or fouling, their discs, seats, and stems can stick, leak, or fail to seal or throttle accurately. Cleaning removes these deposits, restoring smooth operation, proper seating, and reliable actuation, which directly reduces the risk of sudden valve failure.

Cleaning is the best choice because it directly addresses the root cause of many valve problems in wastewater systems— deposits and contamination that impair function. Replacing parts on a schedule ignores actual wear and may waste resources if parts are still usable, or miss issues that cleaning would prevent. Lubrication is usually inappropriate for these valves in this service, since lubricants can contaminate the process, attract dirt, or interfere with sealing. Inspecting only can identify problems but won’t prevent failures caused by buildup.

So, cleaning to prevent failure proactively keeps the valves operating as designed, maintains process control and backflow prevention, and minimizes downtime in the flotation unit.