🔍 Key Concepts

• Interference fit between an O-ring and its groove/surfaces • How compression set and wear affect sealing surfaces • Difference between pressure/flow/temperature effects vs. mechanical fit of a seal

💭 Think About

• What physically keeps an O-ring from leaking in a hydraulic joint: is it pressure, flow, temperature, or how tightly it is squeezed in place? • If an O-ring starts to leak, which of the choices would actually change its shape or size so it no longer presses firmly against the metal surfaces? • Which options are operating conditions of the fluid, and which options describe changes in the O-ring material or geometry over time?

✅ Before You Answer

• Identify which answer choices describe changes in the O-ring itself rather than changes in the hydraulic fluid conditions. • Think about how an O-ring could lose its original shape or elasticity so it no longer presses tightly in its groove. • Eliminate any options that would not directly reduce the mechanical squeeze (interference) between the O-ring and the mating surfaces.