Knob and valve operation (Safety tricks and suggestions) Manejo de las válvulas en SideMount

Every Side Mount diver knows that It´s well accepted in the SM community to use symmetric valves in tanks.
But first of all, where this valves come from?

 
Exactly, they come from the old fashioned doubles or twin tanks, but with a few small modification, instead of a manifold or isolator, there is a plug on each valve, and of course there is not steel bands between tanks at all.

At this point everything sounds simple but it isn´t, why?
Because operation of valves it´s also symmetric !!! Thus we have to twist the knobs against each other.

This is how the valves should be aiming when looking to the diver´s face, 

so the knobs are pointing outwards.

And now, the key question is ... how should the diver twist the knob to open or close the gas flow?

This is a pic taken from the divers view 

Have you ever ridden a motorcycle? If the answer is ¨yes¨, you get more ¨gas¨ twisting the upper part of the right knob to you as in the same way you open the gas flow in the right tank.

And what about the left knob? just in the opposite way. Like when you wring a towel to get it dryed.

This gesture opens both valves.

My personal recommendation is to dive always with both valves fully opened. That means to open the valve up to when it stops and it can´t be twisted still more. Thus you know if you want to close the valve because of a free flow failure you only have to twist it in the only way it can.

Best regards

Moskit Side Mount