Why would one increase cracking pressure to spec on a primary second stage?

[Jim Lapenta]

Is it generally recommended to also (or instead) store a second stage with the diaphragm locked in the depressed position?

Would it be advisable to take either or both of these preventative measures between all inactive periods (for example overnight), or only for periods lasting days, weeks, or months?

Not all regs have a way to lock the purge button. And it's really not necessary. Depending on the reg design, if it's not meant to be locked it may create more problems with other things when someone tries to rig something up to do it.

As for how often to keep the adjustment knob all the way out in the easiest breathing position, I do it after every dive. Why, because it builds muscle memory. The first time someone doesn't do it might remember the next time. Or they may not. Then it's not done after the next dive, dive outing, and pretty soon, not at all. And then they find the seat is not lasting as long as they think it should. It takes a quick motion of the wrist for a split second.

 

[Akimbo]

Divers that use DPVs are another category that might want to detune their primary. This is an argument in favor of side exhaust regulators.

 

[madamimadam]

Not all regs have a way to lock the purge button. And it's really not necessary. Depending on the reg design, if it's not meant to be locked it may create more problems with other things when someone tries to rig something up to do it.

As for how often to keep the adjustment knob all the way out in the easiest breathing position, I do it after every dive. Why, because it builds muscle memory. The first time someone doesn't do it might remember the next time. Or they may not. Then it's not done after the next dive, dive outing, and pretty soon, not at all. And then they find the seat is not lasting as long as they think it should. It takes a quick motion of the wrist for a split second.

Thank you.