HDPE pipes combined with compression fittings form a versatile and highly practical piping system that capitalizes on the strength and durability of high-density polyethylene while leveraging the simplicity and immediacy of mechanical connections. The marriage of these two components allows for a fully plastic piping network that is resistant to corrosion, scale, and chemical attack, yet remains easy to install and modify using standard hand tools. The fundamental operation of an HDPE compression fittings pipe with a compression fitting relies on a straightforward mechanical principle that creates a secure and pressure-tight joint without altering the pipe's molecular structure. Simultaneously, an elastomeric O-ring, typically made of EPDM or nitrile, is compressed between the fitting housing and the pipe's exterior surface to provide the primary hydraulic seal, ensuring no leakage of the conveyed fluid.