Oh my! Your post is simply outstanding. More than I ever hoped for. And I very much appreciate it! More than aa few have this issue, and you have provided the most thorough discussion anywhere on the web. I do understand in detail how a regulator works and understand and tend to agree with your conclusion. My only question is the insistence of others that the diaphragm is controlled solely by the spring tension; atmospheric pressure has no influence. But as you point out, with a very weak spring as the R60 has, I can easily see atmosphere having an influence. But, in the final analysis, is there a solution? I have that bit. BTW, one thing is beyond dispute: atmosphere is indeed having an influence, regardless of any spring.