The function of a gasket is to

• A. Stop the leakage of gases or fluids across mating surfaces
• B. Provide electrical insulation
• C. Reduce friction in joints
• D. Absorb sound

Answer: (A)

Gaskets are used to create a seal between mating surfaces so fluids or gases don’t leak out or in. When the parts are bolted or clamped together, the gasket material compresses and fills tiny gaps and surface irregularities, forming a barrier that withstands pressure, temperature changes, and vibration. This is why gaskets are essential in engines, piping, and valves—where keeping liquids or gases contained is critical. Materials are chosen for chemical compatibility and temperature performance, such as rubber, silicone, PTFE, copper, or graphite, depending on the system.

Electrical insulation isn’t the primary purpose, though some gaskets may offer insulating properties in certain contexts. Reducing friction is handled by lubricants and proper bearing or seal design, not by the gasket. Absorbing sound is typically the job of sound-damping materials, not standard gaskets.