Dumb doubles question

[rhodges]

hey guys, i just set up my first set of doubles and im assuming when carrying them is should avoid using the crossbar as a handle and just grab the valves themselves, is this right? Or is it okay to pickup by the crossbar? I'm guessing not.

Thanks

 

[SeaCobra]

best to avoid hoisting by the crossbar

 

[lowviz]

Do a "Spock thing" with your left hand, put the 'V' around the cylinder neck on your left. Reach down and grab the bottom of the right cylinder and lift the set until it is horizontal to the ground and pulled tight to your waist. Let your legs do the work.

Oh yes: Do not EVER put the set down hard on either cylinder bottom. You will torque the manifold. Gently, gently, gently...

 

[TSandM]

I have been told many times not to lift the sets by the manifold. The cave instructors at Zero G in Mexico routinely carry them that way. Go figure.

 

[RJP]

I find it's just easier to lift with one hand on each valve vs grabbing the manifold anyway.

 

[rhodges]

Thanks for confirming my initial thought

 

[ElGaucho]

The logic goes that if the manifold fails, there is really not much you can do, you face complete gas loss. So that makes the case for avoiding things that could make the manifold fail. Manhandling it from opposite valves, versus the crossbar itself ... it´s an interesting discussion in "theoretical" physics that the internet can always provide (I can even see people posting data from a 1953 study) . Anyhow, I sometimes grab them by the crossbar, specially when going up and down the stairs in my apartment. And I try to grab the tanks by the outer valves most of the times, just because it´s better etiquette. The only truth might be, don´t do strange forcing stuff on an isolator valve, because that might be "the weak point" if you want to find one in a set of manifolded doubles.

 

[Doppler]

I lift my double tanks one at a time... OH, wait! That's sidemount!





And do not lift by the manifold. The thinking being that IF there is ANY play in the bands (and there are plenty of cheap bands out there), the crossbar CAN become slightly misaligned and even a slight contact with the ceiling or wall of a cave, wreck etc, may compromise the orings keeping the compressed stuff in. Never seen it happen BUT I have seen a manifold "give way" while being used as a carry bar... on three different occasions.

 

[captain]

Lifting doubles from the crossover is like Superman holding down a helicopter. How much does he weight, do his feet hold on to the the ground, can he make himself weight enough to overcome the helicopter's lift.
If the weight of the tanks were enough to damage the crossover if you lifted them by the crossover you wouldn't be strong enough to lift them.

 

[robertarak]

The crossbar is called the manifold and it connects the two valves together. Conventional wisdom says not to put undue stress on the manifold since manifold failure can be catastrophic. Also placing the tanks down so one cylinder touches down before the other could also stress on the manifold. To avoid the stresses, one hand on each valve is the preferred method for picking up doubles?

There are no dumb questions. I hope this helps.