Well Burket rate them for 50 Bar for some reason - maybe they don't know what they're doing

What about rule 9.7 of the build regs - All pneumatic components used with pressures greater than 50psi (3.4bar) must be rated/ tested to at least the maximum pressure available in that part of the system.

And 9.8.1 - Rating Pressure relief devices must have a rating of 1000psi (68bar) or 110% of the pneumatic component with the lowest maximum working pressure rating protected by that particular pressure relief device, whichever is the lower.

14 years use, maybe its down to luck? Like I said, its your hand not mine.