Any idea of the cost of a better regulator that can be left on without leakage? Would make more sense than an additional valve for a disposable cylinderThe oxygen cylinders are really designed to be as low cost as possible as they are a disposable product. The additional valve on the cylinder would increase the cylinder cost by about 30%. So we would have to carefully evaluate if this was what guys like yourself want. From our experience the gas already shuts off quite fast if you unscrew the regulator quickly.