A respiratory ventilation apparatus (110, 300) configured to deliver a respiratory gas to a patient interface, comprising: a gas pressurization unit located in a main body of the respiratory ventilation apparatus (110, 300); a humidification assembly being removably coupled to the main body of the respiratory ventilation apparatus (110, 300); wherein the humidification assembly includes a liquid chamber (222, 3000, 3600) configured to accommodate one or more liquids, characterized in that the liquid chamber (222, 3000, 3600) comprises a tank (3002, 3300) and a tank cover (2603, 3004, 3400, 3700), which is pivotally connected to the tank (3002, 3300) through a connection mechanism with a rotational axis; wherein the tank (3002, 3300) comprises an opening for filling at least one of the one or more liquids, wherein the opening is openable by opening the tank cover (2603, 3004, 3400, 3700) and/or closable by closing the tank cover (2603, 3004, 3400, 3700); and wherein the humidification assembly and the main body of the respiratory ventilation apparatus are fluidically connectable by closing the tank cover (2603, 3004, 3400, 3700) and/or fluidically disconnectable by opening the tank cover (2603, 3004, 3400, 3700); wherein the tank (3002, 3300) and the main body are attachable with each other by moving the tank (3002, 3300) in an attaching direction relative to the main body with an angle between the rotational axis and the attaching direction between 20°-160°; and/or wherein the tank (3002, 3300)and the main body are unlockable from each other by moving the tank (3002, 3300) in an unlocking direction relative to the main body with an angle between the rotational axis and the unlocking direction between 20°-160°. a gas pressurization unit located in a main body of the respiratory ventilation apparatus (110, 300); a humidification assembly being removably coupled to the main body of the respiratory ventilation apparatus (110, 300); wherein the humidification assembly includes a liquid chamber (222, 3000, 3600) configured to accommodate one or more liquids, characterized in that the liquid chamber (222, 3000, 3600) comprises a tank (3002, 3300) and a tank cover (2603, 3004, 3400, 3700), which is pivotally connected to the tank (3002, 3300) through a connection mechanism with a rotational axis; wherein the tank (3002, 3300) comprises an opening for filling at least one of the one or more liquids, wherein the opening is openable by opening the tank cover (2603, 3004, 3400, 3700) and/or closable by closing the tank cover (2603, 3004, 3400, 3700); and wherein the humidification assembly and the main body of the respiratory ventilation apparatus are fluidically connectable by closing the tank cover (2603, 3004, 3400, 3700) and/or fluidically disconnectable by opening the tank cover (2603, 3004, 3400, 3700); wherein the tank (3002, 3300) and the main body are attachable with each other by moving the tank (3002, 3300) in an attaching direction relative to the main body with an angle between the rotational axis and the attaching direction between 20°-160°; and/or wherein the tank (3002, 3300)and the main body are unlockable from each other by moving the tank (3002, 3300) in an unlocking direction relative to the main body with an angle between the rotational axis and the unlocking direction between 20°-160°.