Editing Scuba set (section)

====Constant flow scuba====
{{main|Diving regulator#Open circuit free-flow regulator}}
Constant flow scuba sets do not have a demand regulator; the breathing gas flows at a constant rate, unless the diver switches it on and off by hand. They use more air than demand regulated scuba. There were attempts at designing and using these for diving and for industrial use before the Cousteau-type aqualung became commonly available circa 1950. Examples were [[Charles Condert]]'s dress in the US (as of 1831),  and [[Yves le Prieur]]'s hand-controlled supply valve in France (as of 1926); see [[Timeline of diving technology]]. These systems are obsolete as they waste most of the gas or require manual control of each breath, and more efficient demand regulators are available. "[[Ohgushi's Peerless Respirator]]" from Japan as of 1918 had a bite-controlled breathing gas supply valve, which could be considered a form of demand valve, and was successfully used for several years.