How come when I turn any one of the three flow meters on the ball goes up the tube when you first crack the valve of the tank but then sinks out of site. How can I know what kind of pressure I have at the torch. When I first started to tig I used a machine that the flow meters small ball would float up to about 20 lbs and stay hovering there until you shut off the gas. What is the story with the ones at the shop Am I missing something or are they defective? They are all the same brand and model. Thanks for you time and input.