🔍 Key Concepts

• Static vs. dynamic seals – think about whether the seal is used mainly for non-moving joints or moving parts • Cross‑section shape of each seal type (round, U-shaped, V-shaped, X-shaped, etc.) • How pressure is applied to the sealing surface (radial vs. axial sealing)

💭 Think About

• Which of these seal types has a simple, round cross‑section and is typically squeezed between two flat surfaces, like an O‑ring? • For each choice, imagine a piston or shaft: how would that seal sit around it, and what would its profile look like in cross‑section? • Which option is specifically designed to present four sealing lips instead of a single circular contact area?

✅ Before You Answer

• Match the cross‑section profile of an O‑ring (simple circular cross‑section) to the most similar option • Confirm which options (V, U, cup) are lip seals rather than solid round-section seals • Identify which listed seal is explicitly designed as an alternative to an O‑ring for improved sealing with multiple contact lines