Diaphragm/Piston Pressure Reduction Principle of Oxygen Cylinder Regulator

The oxygen cylinder regulator is connected to the oxygen cylinder through the high-pressure input port, and the high-pressure gas in the cylinder is input into the pressure reduction chamber. The high pressure in the oxygen cylinder is usually in the range of 150-200 bar (2200-3000 psi). The main function of the regulator is to reduce the pressure of this high-pressure gas to a low pressure range suitable for the final use equipment, usually between a few bar and tens of bar. The diaphragm or piston mechanism plays a key role in regulating pressure in this process.
Diaphragm Pressure Reduction Principle
The diaphragm is a flexible thin sheet in the regulator, usually made of metal or high-strength rubber material. Its working principle is based on balanced force:
When high-pressure oxygen enters the pressure reduction chamber, the air pressure acts on one side of the diaphragm and pushes against the valve of the regulator.
The other side of the diaphragm applies a reverse force through a spring, and the tension of this spring is controlled by the adjustment knob. The knob adjusts the pressure of the spring, thereby controlling the position of the diaphragm.
When the input pressure of oxygen is too high, the diaphragm will move downward, push the valve to close, and reduce the flow of oxygen; when the input pressure drops, the diaphragm moves upward, opens the valve, and increases the flow.
The movement of the diaphragm allows the output pressure of oxygen to be automatically adjusted, so as to remain within a stable range.
Piston pressure reduction principle
The piston regulator uses a rigid piston instead of a diaphragm, which is connected to the valve and achieves pressure reduction through a similar balance mechanism:
After high-pressure oxygen enters the pressure reduction chamber, it pushes the piston to move, and the piston is also controlled by the reaction force of the spring.
When the piston is pushed by high pressure, the valve is closed, slowing down the airflow; when the air pressure in the bottle decreases, the reaction force of the spring pushes the piston to reset, opens the valve, and increases the oxygen flow.
The displacement change of the piston directly determines the opening and closing degree of the valve, thereby controlling the gas flow and realizing the conversion from high pressure to low pressure.
The advantage of the piston regulator is that its structure is more solid and suitable for use under high pressure and large flow conditions, so it is often used in occasions that need to handle larger flow or higher durability.