How to Determine the Direction of a Check Valve Icon?
2 Answers
Methods to determine the direction of a check valve icon: A check valve is a valve that allows flow in one direction and closes in the opposite direction, preventing the reverse flow of hydraulic oil. In the check valve symbol, the side with the ball is the inlet, and the opposite side is the outlet. The check valve allows fluid to flow only from the inlet to the outlet, preventing the medium from flowing back, hence it is commonly known as a check valve. It is used in hydraulic systems to prevent reverse flow of oil or in pneumatic systems to prevent the reverse flow of compressed air. Check valves come in two types: straight-through and right-angle. Straight-through check valves are threaded and installed in pipelines, while right-angle check valves come in three forms: threaded connection, plate connection, and flange connection.
Identifying the direction of a check valve icon actually has a trick. The icon usually depicts an arrow, with the direction of the arrow indicating the flow direction of the fluid. For example, the tail side of the arrow is the inlet, where the fluid enters, and flows toward the outlet at the head. In automotive repair manual diagrams, the direction the arrow points is where the system flows, so make sure not to install it backward during actual installation. If there's no arrow, a triangular symbol might be used instead, with the pointed end indicating the flow destination. I've seen oil system icons where the arrow points toward the engine interior—if installed backward, the oil would reverse flow, leading to unstable oil pressure and engine wear. The cooling system is similar, with the arrow pointing in the forward flow direction. Diagram annotations usually specify this, so don't rely on guesswork. Getting the direction wrong can degrade the entire system's performance and increase the likelihood of malfunctions. So, develop the habit of carefully examining the details in the diagrams to avoid troublesome repairs later.
