Apollo Expansion PEX is cross-linked polyethylene tubing designed for use within potable water piping systems. Produced using a peroxide method, Apollo Expansion PEX is PEX-A pipe. Having been in use for over 50 years PEX-A pipe has the highest rate of cross-linking of any PEX pipe. Apollo Expansion PEX is the most flexible PEX pipe available. Apollo Expansion PEX pipe provides superior durability, corrosion resistance and flexibility for the most demanding environments. Apollo Expansion PEX is blue for the simple identification of cold water, hot water and main water lines. The Apollo Expansion PEX system is a comprehensive cold expansion piping system comprised of brass fittings, poly alloy fittings, manifolds, valves, fasteners, tools and tubing designed for implementation in water delivery systems, simple or complex.