In a PEX plumbing home run system, the line for each fixture comes directly from central hot and cold manifolds. The Viega MANABLOC combines the hot and cold manifolds into one unit. It is available at SupplyHouse.com with various distribution port combinations and either compression, crimp, or PEX press connections at the ports.
With home run distribution lines there is no need for any fittings between the manifold and the fixtures. Centrally located valves on the manifold can shut off water at any fixture. Hot and cold water arrives at faucets faster, and pressure is more stable when multiple fixtures run.
