Some time ago I urgently needed a second stage for my regulator. I din’t want to spend much on it as it was supposed to be only a temporary solution. So I decided to buy the cheapest thing I could find on the local NZ on-line auction website. I purchased a regulator made in the late seventies (I believe), it cost only a couple of dollars. The set had a piston balanced first stage and two second stages … more that I needed. When the package arrived, it was a pleasant surprise.
Both the first stage and the second stages had no corrosion and no salt on them. The first stage looked very well, but its yoke didn’t have enough space for the valves I was using. The second stages were perfect. When I disassembled them, I discovered a simple mechanism and, most importantly, a silicone membrane. With such a design nothing can go wrong. Since that time I used the second stage many times, it has never failed me.