3 ms·

I thought about using scuba gear for welding, but I was worried about explosion from oxygen in case of leak? FWIW, it's way overkill, but you'd want SCBA (Self

I thought about using scuba gear for welding, but I was worried about explosion from oxygen in case of leak? FWIW, it's way overkill, but you'd want SCBA (Self Contained Breathing Apparatus)[1] not SCUBA (Self Contained Underwater Breathing Apparatus) unless you are, indeed, underwater. Of course the technologies are similar (and can be swapped to a limited degree in a pinch) but SCBA is used when you're not underwater. Those are what firefighters use while attacking fires, or performing trench rescue / confined space rescue / etc. and handling hazardous materials calls. Note that SCBA do not used bottled oxygen... it's just plain air, but under pressure. I'm not a diver, so I don't know as much about SCUBA, but I know they aren't using pure oxygen either, but I think there may be times when they use a mix that is slightly different from plain old atmospheric air. An additional note: SCBA are expensive, require maintenance and need to be refilled with air. All of these things would be a challenge to using one outside of an industrial setting. The "refill with air" part is especially tricky, because you might think "I can use a regular air compressor", but you actually can't, for at least two reasons. One, the pressures needed to fully refill an SCBA tank are higher than a standard shop air compressor. Two, the air also needs to be filtered to remove any contaminants - including, for example, oil used to lubricate the pump on the compressor. As you might guess, fire departments and other SCBA users buy special compressors that are very expensive. And unlike SCUBA, I don't know that there are many, or any, commercial shops where you can walk in and get a bottle filled. If you had a buddy on a local fire department, they might be able to get a bottle filled for you, but no guarantees. Oh, and the bottles also need hydrostatic pressure testing every few years to make sure they are safe to use. [1]: https://en.wikipedia.org/wiki/Self-contained_breathing_apparatus https://en.wikipedia.org/wiki/Self-contained_breathing_appar...

BenjiWiebe 7y ago
And some small rural fire departments don't even have the ability to refill their own SCBA tanks, and instead bring them to a larger department to get them refilled.
- mindcrime 7y ago
  Yes, exactly. Those compressors are expensive. Back in my firefighting days, of the 21 or so departments in my county, I think maybe 3 had their own compressors. A few more had cascade systems, either at their station, or on a truck. So every couple of weeks or so, the other departments would haul all of their bottles to one of the departments that had a compressor, and refill them all (including the cascade bottles). It really is a bit of a hassle, but it's worth it for an application like firefighting where SCBA are an absolute requirement.
dotancohen 7y ago
Most recreational diving is just compressed air, no added oxygen. I wonder if, or why, SCBA gear would use different tank valves than SCUBA gear such that any dive shop couldn't fill one.
- mindcrime 7y ago
  I wonder if, or why, SCBA gear would use different tank valves than SCUBA gear such that any dive shop couldn't fill one. Good point. I don't actually know for a fact that they are different. It may actually be the case that a dive shop would have the capability to fill an SCBA bottle. Now, whether or not they'd be willing to do it is a different question.
- defterGoose 7y ago
  FWIW, nitrox use is pretty common among recreational divers as well, and mixed gas diving is all but a must for tech diving. 32 and 36 percent O2 are most common and up to 40 is ok without taking extra equipment precautions.

BenjiWiebe 7y ago

And some small rural fire departments don't even have the ability to refill their own SCBA tanks, and instead bring them to a larger department to get them refilled.

mindcrime 7y ago
Yes, exactly. Those compressors are expensive. Back in my firefighting days, of the 21 or so departments in my county, I think maybe 3 had their own compressors. A few more had cascade systems, either at their station, or on a truck. So every couple of weeks or so, the other departments would haul all of their bottles to one of the departments that had a compressor, and refill them all (including the cascade bottles). It really is a bit of a hassle, but it's worth it for an application like firefighting where SCBA are an absolute requirement.

dotancohen 7y ago

Most recreational diving is just compressed air, no added oxygen. I wonder if, or why, SCBA gear would use different tank valves than SCUBA gear such that any dive shop couldn't fill one.

mindcrime 7y ago
I wonder if, or why, SCBA gear would use different tank valves than SCUBA gear such that any dive shop couldn't fill one. Good point. I don't actually know for a fact that they are different. It may actually be the case that a dive shop would have the capability to fill an SCBA bottle. Now, whether or not they'd be willing to do it is a different question.
defterGoose 7y ago
FWIW, nitrox use is pretty common among recreational divers as well, and mixed gas diving is all but a must for tech diving. 32 and 36 percent O2 are most common and up to 40 is ok without taking extra equipment precautions.