Miniature Proportional Valve: One of the Most Important Components of Medical Ventilators

Miniature proportional valves used in medical ventilators, commonly referred to as oxygen miniature proportional valves or oxygen flow controllers, are primarily used to control the mixing ratio and flow rate of oxygen and air. Below is an introduction to miniature proportional valves.

Working principle of oxygen miniature proportional valves

Oxygen and air enter the miniature proportional valve from their respective pipelines.

Oxygen and air are mixed in the miniature proportional valve through a set of adjustable apertures.

The mixed oxygen-air mixture is transmitted via pipes to the ventilator.

The ventilator, based on the patient's breathing condition and preset parameters, outputs a specific concentration of the oxygen-air mixture.

In this process, miniature proportional valves control the mixing ratio and flow rate of oxygen and air, thereby achieving precise control over the concentration of the output mixture gas. The size of the apertures and the adjustment of the mixing ratio are achieved through rotating adjustable knobs or automated control systems.

Components of miniature proportional valves

Miniature proportional valves mainly consist of the valve body, regulator, transmission mechanism, spring, and other components. Inside the valve body, there are channels for the mixed gas inlet, oxygen inlet, air inlet, and mixed gas outlet. The mixed gas inlet is the output after oxygen and air are mixed, while the oxygen and air inlets are used for inputting pure oxygen and air respectively. The regulator controls the opening of the miniature proportional valve through a knob or an automatic control system, adjusting the mixing ratio and flow rate of oxygen and air. The transmission mechanism converts the movement of the regulator into the movement of the valve, allowing the valve to control the flow rate of the mixed gas at different openings.

Characteristics of miniature proportional valves

High precision

Miniature proportional valves need to precisely control the mixing ratio and flow rate of oxygen and air to ensure that the ventilator's output oxygen concentration meets the patient's requirements.

Strong adjustability

Miniature proportional valves need to have adjustable characteristics to meet the oxygen needs of different patients.

High safety

Miniature proportional valves need to maintain a stable output oxygen concentration during the use of the ventilator and be able to handle different fault scenarios to ensure the safety of the ventilator.

Good durability

Miniature proportional valves need to have a long service life, maintaining stable performance and precision over multiple uses.

Manufacturing process of miniature proportional valves

Design

First, the design of the miniature proportional valve is needed, including the structure and size of the valve body, the design of the regulator, the design of the transmission mechanism, etc. The design needs to consider the usage environment, performance requirements, and manufacturability of the miniature proportional valve.

Material selection

Based on design requirements and usage environment, select appropriate materials. The materials for miniature proportional valves need to have good corrosion resistance, wear resistance, high strength, and machinability.

Manufacturing

According to the design drawings, manufacture the parts, including the valve body, regulator, transmission mechanism, etc. Manufacturing needs to strictly follow manufacturing processes and quality control requirements to ensure the precision and quality of the parts.

Assembly

Assemble the manufactured parts to form the overall structure of the miniature proportional valve. Assembly needs to pay attention to the precision of components and their fits to ensure the performance and precision of the miniature proportional valve.

Testing

Conduct tests on the manufactured miniature proportional valve, including flow tests, oxygen concentration tests, working pressure tests, etc. The tests need to be conducted according to design requirements to ensure that the miniature proportional valve's performance and precision meet the requirements.