Things Scuba Instructors teach that are either bad or just wrong.

[pauldw]

Her AOW instructor asked me why I didn't get her Nitrox for a particular dive, since she had just completed her Nitrox course. This was a 25 foot reef dive. I said "Um.. Because there's no advantage to Nitrox on a shallow reef dive". He shook his head and said "At our age (55+) we should ALL dive Nitrox on EVERY dive." Really?

Yeah, really. It's a good placebo. And you're ruining it!

 

[Angelo Farina]

Yeah, really. It's a good placebo. And you're ruining it!

High pp of oxygen is not a placebo. It is a very powerful medical treatment, which can heal some illness, but can also cause severe risks.
It is not something to expose yourself liberally, without weighting its benefits and its risks...

 

[60plus]

I have worked with pressurised gases and liquids since the 1970s and have never known a gauge face blow out, nor have I knows a pressure plug blow out. What I have know a few times is diaphragms rupturing or pulling out of their seat which results in an escape of gas from the hole designed for that purpose. It is general good practice to look away from any joint or possible blowout source when turning pressurised equipment on particularly if not wearing appropriate eye protection., this includes the first stage to cylinder valve connection. It is a good idea to blow out or wipe out the first stage dust cover before fitting. My Aqualung first stage is self closing but even so I fit the dust cover and inspect it carefully before fitting to cylinder.

 

[beester]

My first point in red above. There was a time when the blowout plug in an SPG was nonexistant, I still have some around so it's a good rule for me.

Another thing to take into consideration is that one is pressurizing equipment to 125+ psi and 3000+ psi and a failure may occur. I, personally, don't want to be looking at a HP failure when I know I won't be wearing eye protection. I also open valves slowly to minimize any shock to the system which could trigger a failure. Sometimes divers forget how F'n dangerous HP air can be.

Curious why you would want to look at an spg the moment you are turning the valve and pressurizing the system. You can look at it 10 secs later when it's stable, instead of holding it close to your face when you are turning the valve.

 

[Bob DBF]

Curious why you would want to look at an spg the moment you are turning the valve and pressurizing the system. You can look at it 10 secs later when it's stable, instead of holding it close to your face when you are turning the valve.

I don't, however I suppose some divers are impatient to see how much gas they have in the tank. I believe it warning to them.

 

[Wibble]

Curious why you would want to look at an spg the moment you are turning the valve and pressurizing the system. You can look at it 10 secs later when it's stable, instead of holding it close to your face when you are turning the valve.

What about oxygen? Need to slowly pressurise the system, don't want to turn it on fast

 

[beester]

What about oxygen? Need to slowly pressurise the system, don't want to turn it on fast

That is actually true ;-) I do look at the spg when (slowly) pressurising an O2 stage or the O2 on the rebreather.

 

[The Chairman]

SPGs don't explode the way they used to. I'm not sure why, but they don't.

 

[Eric Sedletzky]

SPGs don't explode the way they used to. I'm not sure why, but they don't.

They learned how to build them better so they don’t explode.

 

[Pressurehead]

. It is general good practice to look away from any joint or possible blowout source when turning pressurised equipment on particularly if not wearing appropriate eye protection.

I am sure there are a few here who have been hit with O rings, had one hit me just under the eye last trip, not from my cylinder, someone pressurising their cylinder next to me , the ground around this fill station [on a coral atoll] had O rings all over the place, I picked up at least a dozen.