A PEEP Valve, or Positive end-expiratory pressure valve is a device used for Continuous Positive Airway Pressure(CPAP), Biphasic Positive Airway Pressure (also called Bilevel Positive Airway Pressure) or an intubated patient. On an intubated patient the PEEP valve can be a part of a Bag valve mask assembly or may be attached to the patient circuit on a mechanical ventilator.