Just wanted to go out on a limb and add a little here.... My original objection really had nothing to do with the use of PVC. I have extensions and 90's on the way from Tecme right now. I'm sure using PVC is fine as long as it is done properly. Look at all the gear now, it's usually made of some type of plastic. Has to be related to PVC??? My issue was attempting to make life support equipment from hardware store parts. It struck me as risky at best, if not out right dangerous. I sent a PM to Dave Sutton with the details, but I had first hand knowledge of a Rebreather diver on a homebuild who was killed due to a failure of his breathing/air delivery system. It was nearly 20 years ago when I was a newbie diver. I didn't know anything about Rebreather's, only that his homemade unit cost him his life. It has stuck with me all these years. When I saw the post of someone wanting to make their own rig, I piped up. I thought I was helping keep a fellow diver safe. As it turns out, homemade DSV's are quite common, I just didn't know it until this thread. I love to design and build things. I am genuinely impressed with some of the homebuilt units I've seen on Rebreather World. I have been working on my own Dolphin based homebuild unit for the past few months. I'm quite sure that as another poster said, many of the ideas and designs started in someone's garage as projects. If it works for you....great! *I*personally would not choose a homemade DSV. Just my opinion. FD