fred32176
Contributor
My primary second stage free flows at full open with Venturi assist on - in the water near the surface. It won't free flow in air. And it won't free flow at depth.
Ease of breathing adjustment
- Thread starter Twiny
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I think "free flow" is not the correct words here to describe the orifice/seat adjustment being discussed. I adjust my second stages to leak, barely, they are not free flowing. Most regulators, per the SM, must free flow with the Venturi at maximum when initiated by purging. What we are talking about is a leak, the seat/orifice is not fully sealing when the knob is fully out.
The instructions below require a Venturi free flow in the DIVE or Max position (example G250V):
When a second stage is set to barely leak, not free flow, with the knob fully out, it essentially has 0 inches of cracking effort. As has been described, most regs have a case fault geometry that is roughly equal to 1.0 to 1.2 inches between the center of main diaphragm and the top of the exhaust valve in a normal swimming position. With the seat/orifice adjusted as I am describing, and several others, the regulator will leak annoyingly until the knob is turned in approximately 1/2 turn. It will also be prone to free flow in use if the knob is not turned in. That is what is called a hot tune. I would never set a customers regulator that way, but for me and my wife and most of my buddies, a hot tune is the norm.
The instructions below require a Venturi free flow in the DIVE or Max position (example G250V):
When a second stage is set to barely leak, not free flow, with the knob fully out, it essentially has 0 inches of cracking effort. As has been described, most regs have a case fault geometry that is roughly equal to 1.0 to 1.2 inches between the center of main diaphragm and the top of the exhaust valve in a normal swimming position. With the seat/orifice adjusted as I am describing, and several others, the regulator will leak annoyingly until the knob is turned in approximately 1/2 turn. It will also be prone to free flow in use if the knob is not turned in. That is what is called a hot tune. I would never set a customers regulator that way, but for me and my wife and most of my buddies, a hot tune is the norm.
then yes, it can matter and the IP from full to empty should be taken into account.
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