OK. I see where you get that, Drew. However, I'm positive the 850 bar stamp refers to the proof pressure as measured by crushers. So still in need of conversion to transducer equivalent. Appears there's a small difference of a few hundred psi between the proof pressure figure provided by the Birmingham proofhouse and that listed in your CIP reference. (Note that the Brits didn't actually start using the bar proofmarks until 1985, and even then they were optional--the individual submitting the gun for proof could request either the metric or the old tons marks until 1989, when it became metric (bars) only.) But when the Brits were using the bars marks, those figures referred to proof pressure only, never service pressure.
