Pex Tubing Oxygen Barrier The oxygen diffusion barrier applied to the exterior limits oxygen permeation through the tubing wall in hydronic heating applications which prevents corrosion of ferrous metal parts in the heating system.Click to see full answer. Keeping this in consideration, how do you know if PEX has oxygen barrier? in hot water It often has a shiny gloss to it, compared to non barrier. Rub it together and it will squeak. If you heat it with a match or torch carefully you may see that EVOH layer start to de-laminate from the tube.Furthermore, can oxygen barrier PEX be used for plumbing? Most oxygen-barrier PEX does not have the appropriate approval codes for use with potable water and should not be installed in domestic plumbing applications. Since oxygen from the air can penetrate PEX tubing (even when the PEX is embedded in a concrete slab), an oxygen barrier is needed in most heating systems. In this regard, do you need oxygen barrier PEX? Oxygen barrier PEX is made for heating applications and has thus not been approved for plumbing and drinking water. When using tubing without an oxygen barrier, you must be careful to assure that each and every component in your system is non-ferrous (meaning that it contains no iron).What is orange PEX pipe used for?PEX tubing is flexible, easy to install, and minimizes noise caused by a water hammer. Designed for use on hot and cold potable water lines, Orange PEX tubing is commonly used for radiant floor and hydronic heating applications.