Texas Compressed Natural Gas (CNG) Delivery Truck Driver Practice Exam

The device that controls and maintains a consistent outlet pressure is the pressure regulator. This component is essential in any system where gas is being delivered because it ensures that the supply pressure remains stable, regardless of variations in the inlet pressure or flow demands. By regulating the pressure, the pressure regulator prevents over-pressurization, which can lead to equipment damage or unsafe operating conditions.

In a compressed natural gas (CNG) delivery system, this regulation is vital for monitoring the pressure levels that vehicles use, ensuring safe and efficient fuel delivery. The pressure regulator operates by automatically adjusting the size of the outlet opening to maintain the desired pressure.

Other devices listed, such as flow meters and pressure sensors, serve different purposes. Flow meters measure the volume or mass of the gas flowing through the system, and pressure sensors monitor the pressure but do not regulate it. Safety valves, on the other hand, are designed to release pressure if it exceeds a predetermined level to prevent accidents or equipment failures, but they do not control outlet pressure in a steady operation like a pressure regulator does.