ROC-M Exam case studies
ROC-M Exam · Put your knowledge to work in context.
The Registered Operator Certification – Mechanical (ROC-M) is a professional credential for people who operate, monitor, and maintain mechanical plant equipment - boilers and pressure vessels, pumps and compressors, piping and valves, HVAC and refrigeration systems, and the electrical and control hardware that drives them. It suits stationary engineers, plant and facility operators, maintenance technicians, and utilities staff who need to demonstrate broad mechanical competency rather than narrow specialization. The ROC-M Exam case studies are 5 cases and about 2,643 words.
1Condensate Pump Cavitation After Heat Exchanger Retubing
A building heating loop uses a centrifugal condensate pump rated 40 L/s at 35 m head, drawing from a receiver vented to atmosphere at 101 kPa. The pump sits 4.2 m above the receiver water level.
533 words, about 3 min2Relief Valve Sizing Dispute on a Steam Boiler
A low-pressure steam boiler is rated 3,000 kg/h at 700 kPa gauge with a design pressure of 800 kPa gauge. The existing safety valve is stamped with a capacity of 3,200 kg/h at 700 kPa.
496 words, about 2 min3Compressor Trips on High Discharge Temperature in Summer
A rotary screw air compressor rated 22 m3/min at 800 kPa runs in a plant room that reaches 41 C in summer. It trips on high discharge temperature at 105 C, which is the shutdown setpoint.
469 words, about 2 min4Chilled Water Valve Hunting in a Variable Flow Loop
A variable primary chilled water system serves 12 air handling units. The lead chiller is a 500 kW screw machine with a variable speed drive.
540 words, about 3 min5Motor Overload Trips After Pump Impeller Trim
A 75 kW, 400 V, three-phase motor drives a centrifugal cooling water pump. The pump was oversized, so the impeller was trimmed to reduce flow from 180 L/s to 150 L/s.
605 words, about 3 min