Do you turn the air off or leave it on after setting up on a tank?

[davehicks]

Dave,

A partially open valve will still read the cylinder pressure. Now when a diver descends, then it becomes an issue.

Yes, but by starting at Zero I can turn the valve fully on until it stops. It won't ever be partially open. I do this and recommend it because it is the best way I know of to prevent partial or fully closed valves.

 

[wetb4igetinthewater]

Yes, but by starting at Zero I can turn the valve fully on until it stops. It won't ever be partially open. I do this and recommend it because it is the best way I know of to prevent partial or fully closed valves.

True, but once I came across a diver who complained about breathing at depth, as his valve was partially open.

That's one thing I like about diving sidemount from a boat (or CCR). No one touches my valves trying to "help" me.

 

[Baker_Dive]

I'm an advocate of "do what works for you." If your personal routine is to only have your air on, when your reg is attached, and that works for you, go for it. Changing that now may actually be dangerous for you, simply because of habits you've developed. There's also always some risk of perhaps you got distracted and missed a step, someone else turned off your air, or your regulator got bumped and dumped a few hundred (or thousand) PSI. So I'd caution against assuming a hooked-up-reg is always turned on and ready to go.

That said, it is completely unnecessary to disconnect a regulator to prevent losing air from the tank. For me personally, my routine is always that the tank is always off before any dive, and must always be turned on. I have never jumped in, or almost jumped in, with a tank off. My dive-buddies have done it several times, or I caught them about to jump in that way.


I absolutely agree. For me personally, knowing how my brain works, I deliberately turn off the air and purge most of the pressure. That way:

• (a) the tank is always off pre-dive, there is no guessing, and
• (b) any attempted use of the regulator will immediately show the tank is off; there's no mistaking a pressurized regulator for being on.
• (c) I may be a nice guy, but anyone who touched my equipment gets a lecture.

For me, I need a VERY reliable routine. Yeah, I can wing it and be accurate 98% of the time, but I am occasionally absent-minded.

Assumptions can be dangerous. Specifically, the assumption that "hooked up reg means air is on."

Just because a DM catches people with the air off, doesn't always logically lead to the conclusions you propose. You might said "people nearly jumping in with the air off, is a very good reason to do something to ensure that doesn't happen." What you shouldn't say is "therefore you must follow the same routine I follow."

As I stated above, people should do what works best for themselves and their psychi.

You are correct and there isn’t a “right” way, just what works best for the individual

I think you may have misunderstood my intentions. I don’t just Willy nilly jump in when reg is attached. My intent was to convey the redundancy that works for me. I have two fail safes(if I’m using that correctly, maybe it’s only one). The first is, “oh reg is attached it has air and valve on”. I don’t trust that nor should anybody, a pre dive safety check is highly important. . The second step to my fail safe is I always take three deep breaths staring at spg. That’s my method. Let’s assume I forgot to turn valve on, I’d catch it doing my three breaths. Or let’s assume I forgot to do my three breaths, I’d still have my valve on because I always turn my air on when reg is attached.

A dilligent pre dive safety check is the best way to catch mistakes, no matter how experienced or easy a dive presents itself. Just like I do “cell phone, wallet, keys” check periodically I do air, bcd air blast and pat for weights. I need to incorporate octo purge as I don’t always do that.

 

[davehicks]

True, but once I came across a diver who complained about breathing at depth, as his valve was partially open.

That's one thing I like about diving sidemount from a boat (or CCR). No one touches my valves trying to "help" me.

There is no "True, but" here. I literally explained a method to avoid that issue of closed or partially open valves. We are in agreement here.

 

[wetb4igetinthewater]

There is no "True, but" here. I literally explained a method tho avoid that issue of closed or partially open valves. We are in agreement here.

"Completely opening a valve" is actually a skill I teach now as a result. Exactly as you describe. I explain the importance of such and explain that valves can have different levels of resistance depending on their maintenance. I want them to be wary of being in some far flung location where the valves have never been removed from the cylinder and take effort to open/close. While I tell them also to not wrench of the valve, but if it is sus, go ahead. Definitely do it (or have a buddy do it) if they have pressure but difficulty breathing at depth.

 

[azstinger11]

True, but once I came across a diver who complained about breathing at depth, as his valve was partially open.

That's one thing I like about diving sidemount from a boat (or CCR). No one touches my valves trying to "help" me.

Touch my CCR valves and I break your hand lol

 

[RobPNW]

I assemble everything, turn the gas on and check the pressure on the SPG. Then I close the tank valve until almost time to jump in. Then open the valve back up when getting geared up. An instructor told me that if you have an extensive transit in hot weather, leaving the tank valve open could lead to equipment damage? He didn't go into specifics but obviously if the full tank heats up, the pressure will rise. Can someone speak to specifically what equipment may be vulnerable in that situation?

 

[wetb4igetinthewater]

Touch my CCR valves and I break your hand lol

That's it?!? I will cut you with my EEZYCUT!!!!

 

[davehicks]

I assemble everything, turn the gas on and check the pressure on the SPG. Then I close the tank valve until almost time to jump in. Then open the valve back up when getting geared up. An instructor told me that if you have an extensive transit in hot weather, leaving the tank valve open could lead to equipment damage? He didn't go into specifics but obviously if the full tank heats up, the pressure will rise. Can someone speak to specifically what equipment may be vulnerable in that situation?

I don't know if that story is true or not. The only thing that I can imagine your instructor might have been concerned about is the 1st stage. Having 3000 psi of internal pressure and a very hot environment might cause more stress on a diaphragm or HP o-rings. Perhaps the diaphragm could deform or weaken?

 

[SlugLife]

That's it?!? I will cut you with my EEZYCUT!!!!

I always have this on my harness. Lets just say somebody could lose a finger or two.