no only lines and components that are exposed to o2. This is the fill whip valves ect that are used for filling the o2 before topping off. Top off gas is grade e or better for o2 pp blending. Keep in mind thta the connection to the tank is exposed to o2 then you connect the top off air line. If yo have no check valve to prevent back filling o2 to the air piping it should be clean also . The issue of not putting o2 in a non clean system can be prevented by turning on the gas on the whip and and then opening the valve on the tank preventnig o2 from back feeding.
A blending class would help you in these issues 2-3 hundred is cheeper than an accident.
