I am getting ready to install a new 40 gallon Bradford/White electric water heater tank. It comes with a combo anode-hot water outlet fitting. Both the cold water inlet and hot water outlet fittings (see photo) are "dielectric waterway fittings with 3/4" NPT tapered male threads." There is a plastic lining inside the nipples, white in the hot water outlet and blue in the cold water inlet. Do I leave these plastic linings in place? The reason I ask is because there is also a black membrane across bottom of the plastic linings that looks like it would block the flow of water. Maybe they keep debris from entering the pipes prior to installation and should be removed? Your thoughts?