CPA Equipment Maintenance & Operations 2 — Questions and Answers
Question 1: When inspecting a pump mechanical seal for leaks, what is the acceptable leak rate for a standard single mechanical seal?
- No visible leakage is acceptable
- Up to 10 drops per minute
- Up to 3 drops per minute (Correct answer)
- Up to 1 oz per hour
Correct answer: Up to 3 drops per minute
A standard single mechanical seal should leak no more than 3 drops per minute; anything beyond that indicates seal wear or failure.
Question 2: What is the primary purpose of a pressure relief valve (PRV) on a storage tank or vessel?
- To control flow rate into the vessel
- To prevent overpressure by venting excess pressure (Correct answer)
- To maintain a constant operating temperature
- To regulate fluid viscosity
Correct answer: To prevent overpressure by venting excess pressure
A PRV automatically vents excess pressure to protect the vessel from rupture when pressure exceeds the set point.
Question 3: A centrifugal pump is experiencing cavitation. Which symptom is MOST characteristic of this condition?
- Increased discharge pressure
- Rattling or crackling noise from the pump (Correct answer)
- Decreased suction pressure reading
- Higher than normal motor amperage
Correct answer: Rattling or crackling noise from the pump
Cavitation causes vapor bubbles to form and collapse violently, producing a distinctive rattling or crackling sound like gravel in the pump.
Question 4: Before performing maintenance on a heat exchanger that contains flammable hydrocarbons, which step must be completed FIRST?
- Replace the gaskets
- Purge and blind the equipment (Correct answer)
- Apply new insulation
- Calibrate the pressure gauges
Correct answer: Purge and blind the equipment
Purging removes hydrocarbons and blinds (spectacle blinds) isolate the exchanger from the process to prevent exposure to flammable materials.
Question 5: What does the term 'MAWP' stand for in the context of pressure vessel maintenance?
- Maximum Allowable Working Pressure (Correct answer)
- Minimum Acceptable Water Pressure
- Mechanical Average Work Parameter
- Mean Allowable Wall Pressure
Correct answer: Maximum Allowable Working Pressure
MAWP stands for Maximum Allowable Working Pressure, which is the highest pressure a vessel is designed to handle safely.
Question 6: Which type of valve is BEST suited for throttling (flow control) applications in petroleum operations?
- Gate valve
- Ball valve
- Globe valve (Correct answer)
- Check valve
Correct answer: Globe valve
Globe valves are designed for throttling because their plug-and-seat design provides fine control over flow rate.
Question 7: When using a torque wrench to tighten flange bolts on a process piping joint, what is the correct tightening sequence?
- Clockwise from the 12 o'clock position
- Tighten all bolts hand-tight, then use a cross-pattern sequence (Correct answer)
- Random order until all bolts are snug
- Tighten the bottom bolts first, then the top
Correct answer: Tighten all bolts hand-tight, then use a cross-pattern sequence
Hand-tightening first, followed by a cross (star) pattern, ensures even gasket compression and prevents flange distortion.
CPA Equipment Maintenance & Operations 2
When inspecting a pump mechanical seal for leaks, what is the acceptable leak rate for a standard single mechanical seal?