Oilers/Plant Tenders (HHC) Civil Service Practice Exam 2026 - Free Oilers & Plant Tenders Practice Questions and Study Guide

A valve that allows oil to flow in one direction only is known as a check valve. This type of valve is designed to prevent backflow in a piping system. When fluid flows in the intended forward direction, the valve opens, allowing the fluid to pass through. However, if the flow reverses, the valve closes automatically, stopping the fluid from flowing back. This function is crucial in hydraulic systems, where it is essential to maintain the correct flow direction and pressure.

The other types of valves serve different purposes: an actuator valve is typically used to control the movement of a mechanism, a throttle valve regulates the flow and pressure of fluids, and a control valve adjusts the flow and pressure in a system based on a signal from a controller. Each of these valves plays a distinct role, whereas the primary role of a check valve is specifically to ensure unidirectional flow.