CPA Equipment Maintenance & Operations 5

Question 1

What is the purpose of a 'pigging' operation in a petroleum pipeline?

Accepted Answer

To clean, inspect, or separate products inside the pipeline using a pig device

Answer

Pipeline pigs are devices propelled through the pipe by product flow to clean deposits, separate batches, or carry inspection sensors.

Question 2

Vibration analysis on a rotating machine shows a dominant frequency at exactly 1× running speed. This pattern MOST likely indicates:

Accepted Answer

Imbalance in the rotating element

Answer

A 1× running speed (1X) vibration signature is the classic indicator of rotor imbalance, where the center of mass doesn't align with the rotational axis.

Question 3

A double block and bleed valve arrangement provides isolation by:

Accepted Answer

Closing two block valves with a bleed valve between them to verify and vent any leakage

Answer

Double block and bleed uses two in-line block valves with a bleed (vent) valve in between; opening the bleed confirms both blocks are holding and releases trapped pressure.

Question 4

What is the function of a vapor recovery unit (VRU) at a petroleum storage facility?

Accepted Answer

To capture and recover hydrocarbon vapors displaced during tank filling operations

Answer

VRUs capture hydrocarbon vapors displaced from tanks during filling, recovering saleable product and reducing emissions instead of venting to atmosphere.

Question 5

When performing laser shaft alignment on a pump-motor set, the acceptable tolerance for angular misalignment in a high-speed machine (>3600 RPM) is typically:

Accepted Answer

Less than 0.5 mils/inch

Answer

High-speed machines require tighter alignment tolerances — typically under 0.5 mils/inch angular — because misalignment forces increase with rotational speed.

(CPA) Certified Petroleum Apprentice Practice Test

(CPA) Certified Petroleum Apprentice Practice Test

CPA Equipment Maintenance & Operations 5