For what it is worth, I replaced a combination of PVC/Iron pipe. I could not believe how filthy, rusty and dirty the insides of the iron pipe were. They had only been up about 2 years and used very little. I am so glad I made the switch to MaxLine. From all I have seen your product is a winner and so are the people I’ve had the pleasure to deal with thus far. I look forward to future orders from RapidAir.