Wed Dec 10, 2014 6:05 pm
Thanks for the input Folks. I've checked the burst disks on all three and they are all at around 5000psi. or the BAR equivalent. Hmm? Which one to use? Decisions, decisions....?
I agree that the yoke must be able to withstand higher pressure settings. As you all know, the original yokes from the 40s to the early 70s were designed for pressures of 2250-3000 depending on make, model and year of manufacture. As I and all of you can attest to seeing "yoke stretch" or "jump" when you hook up a vintage DAAM to 3000 psi. tank. Though I have read in this forum (I forget where) that it was common for the military to use 3000 psi on DH regs. in the late 50s to the mid 70s, I will not do so on my vintage babies.
The simple fix is to tailor the tank fill to meet the regulators operating specifications. That is why I want to double up with modern steel 80s. For example, if I have a vintage reg that can withstand a yoke pressure of 2600psi. and safely operate at tank pressure 2600 psi. I fill the HP 3442 doubles to that level and dive it. With double 80s, 2600 psi. will give me approximately 75% capacity, or 120 CF. You can dive for a good while on a 120 cubic feet of air. Full capacity is no problem of course with a Phoenix HPR, or a Kraken, or any reg that has a yoke strength of 3500 or higher.
I don't think it is wise to "push" the engineering specs on regulators that were built at the time I was born (54 years ago) beyond their original design limits at this point in time. Though vintage DH regs were engineered extremely well (over engineered really), to exceed their original operational paradigms (I feel) could invite catastrophic yoke failure, or invite possible regulator failure internally (regulator freeze or "lock up"), even if you have replaced seats and diaphragms with new ones. Metal fatigue and general wear do to age and inception should be taken into account for safety as well as to preserve the reg. for future generations of divers use.
"Where'd ya get that ol' thang, don't cha' know them thare things ill kill ya!"
Live From the Red Sea,
Russ