One had a gauge connected to a line downstream from a quick open/shutoff valve. When the quick opening valve was activated, the rapid change in pressure caused an internal seal of their pressure gauge to rupture, allowing water into the gauge casing.
The gauge was rated for the nominal pressure the customer was measuring, but the pressure spike pushed past that pressure range just enough to break the gauge and make it unreadable.
It happened with two makes of the gauge from separate vendors, so the customer knew it wasn’t faulty manufacturing.
We recommended the customer look into a snubber, a specialty part with a few different design types which work to arrest rapid pressure fluctuation and spikes by slowing the maximum speed a substance can travel.
Snubbers also make gauges measuring quickly oscillating media more readable and less likely to suffer damage.
Those familiar with plumbing might equate them to water hammer arrestors installed in homes to lengthen the life of the pipes…