ETC ETC Mechanical Systems & Equipment 2

Question 1

What is the purpose of an expansion joint in a piping system?

Accepted Answer

To allow for thermal expansion and contraction without stressing pipe or equipment

Answer

Expansion joints absorb dimensional changes caused by temperature variations, preventing thermal stress and potential failure in piping systems.

Question 2

What does NPSH represent for a centrifugal pump?

Accepted Answer

The pressure available at the pump inlet above vapor pressure, preventing cavitation

Answer

NPSH is the difference between the absolute pressure at the pump suction and the vapor pressure of the liquid, determining whether cavitation will occur.

Question 3

What is the purpose of a pressure reducing valve in a water distribution system?

Accepted Answer

To reduce upstream pressure to a lower regulated downstream pressure

Answer

A PRV reduces high upstream water pressure to a safe, regulated level suitable for building fixtures and piping systems.

Question 4

What is the refrigeration cycle's primary purpose in an air conditioning system?

Accepted Answer

To transfer heat from the indoor space to the outdoor environment using a refrigerant

Answer

The refrigeration cycle uses a refrigerant to absorb heat inside the building and reject it outside, cooling the interior space.

Question 5

What does brake horsepower measure for a pump or motor?

Accepted Answer

The actual power delivered to the pump shaft, accounting for mechanical losses

Answer

Brake horsepower is the actual mechanical power delivered at the shaft, which is less than motor nameplate power due to mechanical inefficiencies.

(ETC) Engineering Technician Certification Practice Test

(ETC) Engineering Technician Certification Practice Test

ETC ETC Mechanical Systems & Equipment 2