Movable long-tube positive pressure emergency long tube air breathing apparatus Movable long-tube positive pressure ... , 4 air cylinders, 2 high pressure connecting ducts, 2 exhaust valve, 2 single-direction valves, 1 reducer base, 1 reducer, 1 ... person’s use under medium labor intensityOpening pressure of safety valve (Mpa)1.1-1.5Max air supply (L/min)300Methods ...