'Vintage' piston 1st-stage main springs, is there a danger of metal fatigue/spring snapping in two?

[KeithG]

I am curious since I only know about my Sherwood regs: how does a spring get rusty? Why are people so worried about rust?

The spring in my Sherwood is never exposed to the water, so it will not rust.

Do other designs allow this as normal operation?

 

[tbone1004]

I am curious since I only know about my Sherwood regs: how does a spring get rusty? Why are people so worried about rust?

The spring in my Sherwood is never exposed to the water, so it will not rust.

Do other designs allow this as normal operation?

most regulators allow the springs to be in direct contact with ambient conditions, air at the surface, water when diving as most regulators are unsealed. Sealed pistons are rare, and while sealed diaphragms are very popular on this forum, they are a small percentage of those in the wild

 

[Eric Sedletzky]

most regulators allow the springs to be in direct contact with ambient conditions, air at the surface, water when diving as most regulators are unsealed. Sealed pistons are rare, and while sealed diaphragms are very popular on this forum, they are a small percentage of those in the wild

Oh, I’ll bet there are way more diaphragms out there than you think. I’ll bet the ratio is around 50/50 (or more).
Just think of all popular brands and even off brands that use diaphragms around the world.

 

[tbone1004]

Oh, I’ll bet there are way more diaphragms out there than you think. I’ll bet the ratio is around 50/50 (or more).
Just think of all popular brands and even off brands that use diaphragms around the world.

sealed diaphragms is the important distinction. I'm sure the ratio is close to 50:50, but what's the percentage of sealed diaphragms, and I'd bet unsealed is at least 5:1