CPE Mechanical Systems & Equipment 2

Question 1

A centrifugal pump is operating in cavitation. Which symptom is MOST characteristic?

Accepted Answer

Rattling or crackling noise with erratic flow

Answer

Cavitation causes vapor bubbles to implode violently, producing a rattling noise and unstable flow.

Question 2

What is the primary purpose of a mechanical seal in a rotating pump?

Accepted Answer

To prevent fluid leakage along the shaft

Answer

Mechanical seals use lapped mating faces to prevent process fluid from leaking along the pump shaft.

Question 3

Which gear type is BEST suited for transmitting high torque between parallel shafts with low noise?

Accepted Answer

Helical gears

Answer

Helical gears have angled teeth that engage gradually, reducing noise and enabling higher torque transmission between parallel shafts.

Question 4

The Net Positive Suction Head Required (NPSHr) for a pump is determined by:

Accepted Answer

The pump manufacturer based on impeller design

Answer

NPSHr is a pump characteristic established by the manufacturer through testing and is fixed for a given pump and flow rate.

Question 5

A V-belt drive shows excessive slippage. The FIRST corrective action should be:

Accepted Answer

Check and adjust belt tension to specification

Answer

Insufficient tension is the most common cause of belt slippage, and adjusting tension to the manufacturer's specification corrects this before replacement is considered.

(CPE) Certified Plant Engineer Practice Test

(CPE) Certified Plant Engineer Practice Test

CPE Mechanical Systems & Equipment 2