Oxygen flow meters are mainly used in medical units for oxygen inhalation for patients. The main structure is composed of two parts: flow regulator and pressure reducer.

1.Two types of oxygen flowmeter

At present, there are two main ways for the hospital to provide oxygen:  oxygen flowmeter regulator and wall pipe oxygen supply. One type of oxygen flow meter is with the pressure reducer and humidifier bottle, and the other type is with a humidifier bottle only. The working principle is that the oxygen in the bottle (oxygen source) is reduced by the pressure reducer. The pressure action changes from the original high-pressure oxygen to low-pressure oxygen, and after the flow is regulated by the oxygen flow meters, it can be output by the output nozzle at a constant flow value.

2.Common failure, cause analysis and solution of oxygen flowmeter

1.Turn the flow adjustment knob, the float changes not linearly but suddenly increases or decreases

The general reasons for this situation are: (1) the front end of the flow adjustment rod is poorly sealed, which is caused by the wear or aging of the seal ring for a long time, as long as the seal ring of the same type is replaced, the fault can be eliminated; (2) The glass display tube is not suitable. This situation is mostly caused by the mismatch in the geometry of the cone surface of the replacement display tube after the display tube ruptures. Replace the original display tube with the same model.

2. The float of the flow regulating valve does not move

Inspection and treatment methods: (1) First observe whether the float and the inner tube of the oxygen flow meters are blocked at the gas outlet. The reason is that the remaining water in the humidifier bottle is not cleaned during storage so that the water enters the gas outlet of the oxygen flow meter main body and rusts with the tip of the float. Solution: Remove the main body of the oxygen flow meter, clean it with carbon tetrachloride and dry it (do not use organic solvents such as gasoline); (2) If there is no abnormality, you can remove the oxygen flow meter part and observe the output of the working pressure of the pressure reducer. If there is no output of the working pressure, it can be determined that the pressure reducer is faulty.