Valves seem small, but choosing the right one changes performance, safety, and reliability. Let’s break down 4 types used in fluid systems: check, ball, plug, and butterfly. Check valve → lets flow go one way only (no backflow) Ball valve → open/close with a hollow ball inside that rotates 90° Plug valve → similar to ball, but uses a plug with a hollow core to align/block flow Butterfly valve → rotates a disc in the flow path to regulate or isolate 👇 In the first comment: internal parts, pros/cons, and examples in real systems. Which of these valves have you seen in real life (plumbing, car, machines)? Tell me below. #STEM #Engineering #FluidDynamics #Valves #MechanicalDesign #LearnEngineering