The previously given advice of 3 times the nominal diameter plus 2 = number of turns to open/close a gate valve is generally pretty good.
It should be remembered this will not hold true on large valves that have a gearbox installed (either spur gears or bevel gears.) The gearbox should...
I am doubtful these particles are SBR elastomer. You mentioned finding one "corroded" SBR gasket in the system. Are you certain it is SBR?
Several years ago, there was an article in the AWWA JOURNAL that reported exposure to chloramine deteriorated virtually all elastomers to some degree...
Although electrons are present in the conductor, electrons won't flow, or move from atom to atom until the conductor sees a potential difference across itself, (voltage). With a voltage applied, one end of the conductor appears negative while the other end appears positive. Electrons are...