Bellows are categorized by shape and function: U-type (simple, cost-effective, ideal for general displacement), V-type (stiff, suited for high-pressure systems), Ω-type (long fatigue life, for cyclic movement), and flat-type (compact, for tight spaces). Sealed bellows (welded ends) prevent fluid leakage, while open-ended models connect to pipes or machinery.

In oil and gas, bellows absorb thermal expansion in pipelines, avoiding rupture from temperature fluctuations. Automotive exhaust systems use stainless steel bellows to decouple engine vibration, reduce noise, and accommodate chassis-engine misalignment. Aerospace depends on lightweight, heat-resistant metal bellows for jet engine fuel lines and hydraulic systems, surviving extremes from -50°C to 650°C. Medical devices leverage flexible, non-toxic silicone bellows in ventilators and dialysis machines, ensuring patient safety and precise fluid control. Construction uses bellows in plumbing to compensate for building settlement, reducing structural damage from ground movement.