Instrumentation & Equipment Maintenance Flashcards
7 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Instrumentation & Equipment Maintenance flashcards as text
A centrifugal pump experiences cavitation. Which corrective action is most appropriate?
Answer: Reduce suction head or increase NPSH available
Cavitation occurs when NPSH available falls below NPSH required, so increasing suction pressure or reducing inlet losses eliminates vapor bubble formation.
What instrument is used to verify that a rotating shaft is operating within acceptable vibration limits?
Answer: Accelerometer or vibration sensor
An accelerometer or vibration sensor measures mechanical vibration amplitude and frequency to detect imbalance, misalignment, or bearing wear in rotating equipment.
Which type of heat exchanger maintenance is performed to remove scale and fouling deposits from tube surfaces?
Answer: Chemical or mechanical cleaning
Chemical cleaning (acid or solvent) or mechanical cleaning (rodding or high-pressure water jetting) removes fouling deposits that reduce heat transfer efficiency.
What does the abbreviation 'P&ID' stand for in process plant documentation?
Answer: Piping and Instrumentation Diagram
P&ID stands for Piping and Instrumentation Diagram, which shows the interconnection of process equipment, piping, and instrumentation.
A safety relief valve (SRV) is leaking continuously at normal operating pressure. What is the most likely cause?
Answer: Operating pressure too close to set pressure
When operating pressure is within 10% of the set pressure, the valve disk may 'simmer' or leak due to insufficient margin between operating and set pressure.
Which sensor type measures level based on the weight of the liquid column above it?
Answer: Hydrostatic pressure transmitter
A hydrostatic pressure transmitter measures the pressure exerted by the liquid head above it, which is proportional to the liquid level and density.
During a loop check on a new installation, what is the technician verifying?
Answer: That the instrument signal correctly reaches the control room and the associated device responds
A loop check verifies end-to-end instrument signal integrity — from field transmitter or device through wiring to the control system — and confirms correct controller response.