mario
i test and adjust my relief valves, pressure switches and my custom made stuff in the workshop normally with a enerpac hand pump (and AFAIK, you too), works up to 1500 bar with normal hlp 32. works easy, properly and safe, needs no heavy aditional equipment, but cleaning after test can be a problem on a event.
the annoying word in the rules is certified.
In austria and germany a certified PRD is 2 times more expensive than the equivalent normal valve (same brand and type, but pre-adjusted and sealed).
in all the rules (RW, BB, FRA) i´m still missing the nominal flow of the PRD at relief pressure. Theoretically I can use a certified NS 0.1 mm PRD, witch is useless in some cases of overpressure.