The Devilbiss Bubble humidifier provides humidified oxygen to patients to minimize discomfort and the potential health risks of breathing a dry flow of oxygen such as nose bleed. The Devilbiss bubble humidifier works in conjunction with DeVilbiss Oxygen Concentrators. A pressure relief valve and down spout diffuser design allow high flow delivery (6-15 LPM). This humidifier is specifically suited for applications where delivery via face masks requires high oxygen flow rates to maintain desired oxygen saturation. The 360 degree diffuser head provides superior gas hydration with very low operation volume. The pressure relief valve automatically resets and also has an audible pressure relief alert to warn of any potential patient or equipment hazards. Low water turbulence and tight, large wing nut securely seals in pressure and prevents rain-out.