Reggie
Established Member
- Joined
- Mar 20, 2006
- Posts
- 1,642
I haven't worn my wedding ring in over 6 years due to being on site.I've even given myself a nasty cut on a car door due to a wedding band.
Really not my area but I might guess the difference is due to what they're trying to achieve in both cases. With a pilot (i assume) you want to add oxygen to the air, and do so by pumping it into the mask. So a *bit* of leakage of contaminant free outside air might not be a problem as most (90+%) of the inhaled volume will come from the proper source. :?:
Whereas a respirator in mining/processing has to filter dirty air full of noxious gases. So a bit of leakage via a lower resistance flow path, compared to the filter, could create more problems.
Edit: easy to agree on factual stuff.
Edit2: just been reminded about positive pressure by PM. My comments here don't apply to positive pressure devices. Do aircraft use positive pressure for pilots?
Oxygen supplied to pilots would be via pressurised tanks thus yes pressurised.
Yes the resporators can't have leakage for noxious gas or toxic particles like asbestos
There is also the issue for mines rescue personnel using closed circuit breathing apparatus, were the used is recirculated, filtered resupplied with some oxygen added.