G3 G3 - Gas Technician Level 3 Pressure Regulation and Control Questions and Answers 1

Question 1

What is the primary function of a gas pressure regulator?

Accepted Answer

To reduce and maintain a constant downstream gas pressure regardless of upstream fluctuations

Answer

A pressure regulator automatically reduces inlet pressure to a stable, lower outlet pressure suitable for appliances.

Question 2

In a two-stage gas distribution system, the first-stage regulator typically reduces line pressure from high pressure to approximately:

Accepted Answer

2 psi (medium pressure)

Answer

First-stage regulators in two-stage systems reduce high-pressure distribution gas to an intermediate medium pressure of around 2 psi for delivery to homes or buildings.

Question 3

The outlet pressure for most residential gas appliances in the US served by natural gas is typically:

Accepted Answer

3.5 in. W.C. (approximately 0.87 kPa)

Answer

Most residential natural gas appliances are designed to operate at 3.5 in. W.C. (about 0.125 psi) outlet pressure.

Question 4

A pressure regulator that allows outlet pressure to rise above its set point when gas flow stops is said to exhibit:

Accepted Answer

Creep

Answer

Creep (also called lock-up pressure rise) occurs when a regulator allows pressure to drift upward above set-point at zero flow due to a worn or improperly seated valve.

Question 5

What is 'droop' in the context of a gas pressure regulator?

Accepted Answer

The decrease in outlet pressure that occurs as gas flow demand increases

Answer

Droop is the reduction in regulated outlet pressure as flow through the regulator increases, a normal characteristic of spring-loaded regulators.

G3 - Gas Technician Level 3 Certification Practice Test

G3 - Gas Technician Level 3 Certification Practice Test

G3 G3 - Gas Technician Level 3 Pressure Regulation and Control Questions and Answers 1