Red Seal Gasfitter — Class B Practice Exam 2025 - Free Practice Questions and Study Guide

The correct choice is a regulator, as it is specifically designed to control the flow and pressure of gas within a system under designated conditions. Regulators are essential components in gas systems, ensuring that the gas is delivered at a consistent pressure that is safe for appliances and equipment. They do this by reducing the high pressure of the gas from the supply line to a lower, usable pressure while also maintaining that pressure despite fluctuations in the feed line.

In contrast, a burnisher typically relates to a finishing tool used in woodworking and metalworking rather than gas flow control. A conducer is not a commonly recognized term in gas systems, though it might imply a conduit or passage for gas flow, which does not serve the purpose of regulating pressure or flow. A compressor is used to increase the pressure of gas or air, but it operates under a different principle than that of a regulator. Compressors are generally employed in scenarios where gas needs to be pressurized for storage or transport, rather than to control its flow at usable levels.