Why turn cylinder knob back 1/4 turn?
- Thread starter dlwalke
- Start date
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Soggy
Contributor
One reason is to prevent the knob from sticking open due to the pressure.
Yup.. same reason that when you screw down a locking gate carabiner that's going to be loaded.. you back it off half a turn or so. Those things have a nasty tendency to get way stuck when they're tightened down then loaded. I had to cut myself off a rope once because I forgot to
raxafarian
Contributor
just open it and leave it... don't crank it open HARD...
If you must back it off the stop... just a hair, 1/4 in. not required.
Pet peeve of mine to have a DM on a boat in the carrib. check my valve to be open, and then turn the valve back with a "flick of the wrist"
If you must back it off the stop... just a hair, 1/4 in. not required.
Pet peeve of mine to have a DM on a boat in the carrib. check my valve to be open, and then turn the valve back with a "flick of the wrist"
Soggy
Contributor
Yeah...SSI still teaches "1/2 a turn"
Gee...thanks for cutting off some of my air supply! I may not need it now, but when I breath a tank down to 150 psi because something went wrong I might.
Ari
Moderator
Tried to do it when it is stuck open?
When you turn it back 1/4-1/2 turn it is very easy, only touching it, to make sure it is open, prior to jumping from the boat into the water?
Ever jumped in with the valve closed? I did.
Ari
When you turn it back 1/4-1/2 turn it is very easy, only touching it, to make sure it is open, prior to jumping from the boat into the water?
Ever jumped in with the valve closed? I did.
Ari
sheck33
Contributor
how would a valve get stuck open when you just open it without cranking it open? Same with a carabiner, you screw it closed without cranking and LEAVE it, NO need to either turn the valve back or unscrew a carabiner, people have problems with carabiners because they load them and THEN screw them in further, yes, then you have a problem.
tankvalves, open them and LEAVE them, god knows how many people open a tank and then turn it back '1/2 a turn or so', i see divers almost CLOSE their valves doing that all the time.
So, NO dont close them whatever number of turns after opening, just dont crank a valve open and you will be fine.
tankvalves, open them and LEAVE them, god knows how many people open a tank and then turn it back '1/2 a turn or so', i see divers almost CLOSE their valves doing that all the time.
So, NO dont close them whatever number of turns after opening, just dont crank a valve open and you will be fine.
Ari has the right idea. That 1/4 turn makes it easy during the buddy check to varify that a tank valve is open. I'm sorry, but the "restriction" caused by your valve being closed 1/4 or even 1/2 of a turn is so small I doubt it could even be measured.
sheck33
Contributor
The problem is that many divers turn it back a lot more than 1/4 or 1/2 a turn. I do buddychecks but i dont want my valves touched unless i specifically ask my buddy to. And it is just as easy to verify a tankvalve is open when it is opened all the way, you do know what way to turn a valve to open and close it right?
ScubaScott
Guest
...... a lot sooner than when you reach the end of the thread. Turning back a 1/4 or even 1/2 a turn does nothing to your air pressure, nor it will do anything about reducing the actual volume of air.
SS
SS
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