Valves closed but regs pressurised?

[Rogerdd]

Tank valves on/off and regs pressurised: what’s the standard way during predive?

For example when diving backmount twinset with deco bottle, I first analise backgas and deco gas, screw in the first stages, open the tank valves, and check that the regs and spg are working (for the regs I take a quick breath, not just pushing the purge button), then close the valves (both twinset and deco bottle) but leave all the regs pressurised.

The gear is then transported to the boat, and I get ready.
Once on the boat and before jumping into the water I will do my routine which involves turning the twinset valves open and do another quick check of the regulators
For the deco bottle I will reopen the valve, check the reg (still by doing a quick breath, usually with the reg still tucked in), and turn the valve shut without purging the reg (I will reopen the valve only during gas switch underwater).

Postdive I will turn all the valves off and purge the regulators before unscrewing them from the tanks.

Is that the normal way?

 

[LFMarm]

I don’t think there is one way because of the many variables regarding transportation etc

In general, whenever a regulator gets wet, it needs to be pressurized to avoid water ingress in the first stage. Either with valve closed or open.

Normally, you want to keep valves closed during transportation to avoid unwanted gas discharge from the whole tank.

When diving, you want to keep open the tanks that you plan to use in the short term (eg diluent, inflation for wing, suit, etc) but closed the ones you are unlikely to use (eg bailout bottles).

An additional consideration are AI transmitters. If you have those and tanks are not getting submerged, you typically want to release pressure from the regulators to stop transmitting and using the battery.

 

[Rogerdd]

Thank you, so it appears that what I’m doing doesn’t sound too bad if I understood you correctly (keep valves shut when not in use after setting up, but keep regs pressurised).

Reason I was asking is that I got used to not purge the regs unless I was about to disconnect the regs from the tanks after the dive, but I dived with someone a few days ago who insisted on turning the valves off and also purging the regs when they finished setting up

 

[mr_v]

@Rogerdd - is that your complete reg check procedure? If so, you may be missing a few steps, e.g., checking IP, ensuring that the reg/hoses can keep the pressure. There is a checklist sticky in the Regulator sub-forum - check it out.

Also, when you attach your reg to a tank, try breathing from the reg without turning the valve on. If the reg is tight, you won't be able to breathe. If you can breathe - even if it is just a sip - there is leakage somewhere.

At the end, it all depends on your sense of adventure.

 

[Rogerdd]

There’s a lot more to to my routine but just wanted to check this specific part

 

[jborg]

When I dove with a transmitter I would close and purge (backgas) after setting up gear, to save on transmitter battery. Now I typically don't have a transmitter, and more often just leave the regs charged.

 

[happy-diver]

I check my gear when cleaning it, then again the day before the dive, and then again when I jump in the water

 

[johndiver999]

There’s a lot more to to my routine but just wanted to check this specific part

The (potential) problem with your protocol is that it increases the chance that you will submerge with your tank valves off and then you might die. Perhaps that is not a big risk for you or something you might not worry about.

If you have the regs pressurized and tank off and you jump in, you can get pretty deep, just breathing the air from the pressurized regulators. I've seen someone actually do this and make it to 60 feet, believe it or not, and then the "fun begins" because there is no air to inflate the BC either.

 

[broncobowsher]

Valves off, depressurize.
If you have pressure in the hoses you can get a couple of breaths off that. Which isn't enough when you first enter the water. Enough to enter the water as you did your pre-check and all was good.

 

[InWay2Deep]

I don't leave my backgas (sidemount tanks) pressurized unless I'm in the water ready to go as it drains the transmitter batteries. I will test them before leaving the house but then purge. As for stage/deco bottles I run an in-line shutoff on the regs. When jumping I have the 1st stage charged and the reg shutoff, then when dropping it I turn it on, check pressure and turn it off and make sure the shutoff is turned off. I do this incase the reg loses pressure while I"m away from it, I dont get any nasty water inside the line and up into the second stage. I only use brass/glass on my stage/deco bottles.