What is the function of an expansion joint?

The primary function of an expansion joint is to absorb movement and reduce stress in piping systems. Piping systems are subject to various stresses caused by temperature changes, pressure fluctuations, and even ground movement. Expansion joints accommodate these movements, preventing potential damage to the pipes, their joints, and associated equipment. By allowing for thermal expansion and contraction or misalignment, expansion joints play a critical role in maintaining the integrity and longevity of pipe systems, particularly in environments subject to significant temperature changes or vibration.

In contrast, the other options do not capture the function of an expansion joint. Increasing water pressure pertains to the operation of pumps or compressors rather than the role of an expansion joint. Holding pipe sections together refers more to the function of flanges, couplings, or clamps, which mechanically connect pipes rather than absorbing movement. Providing a measurement reference for pipe length does not align with the primary role of expansion joints, which is to accommodate movement rather than serve as a reference point.