From inlet to outlet: The flow of our O₂ booster

Compressing flow

The blue lines represent the compressing flow (A). Low-pressure O₂ flows through the booster, is compressed to a higher pressure, and then discharged through the outlet.

Regulating flow

The green line represent the regulating flow (B). When the flow decreases to the turndown limit of the VSD, the regulating valve automatically opens to recycle excess oxygen to the booster inlet, maintaining stable and continuous operation.

Blow-by flow

The gray line represent the blow by flow (C). Blow-by occurs when, as the piston moves upward to compress oxygen (O₂), a portion of the gas leaks between the piston and the cylinder wall and passes into the crankcase. During normal operation, if the O₂ pressure exceeds the safety valve setpoint, the safety valve will release oxygen to relieve the excess pressure. In addition, when the O₂ booster stops, it will vent the remaining compressed oxygen in the system. The blow-by flow collects all of these released O2 and directs them safely out of the booster.

1-stage flow

A = Compressing flow

B = Regulating flow

C = Blow-by flow

1 = Inlet

2 = Strainer

3 = Solenoid valve

4 = Motor

5 = Pump block

6 = Cooler

7 = Regulating valve

8 = Solenoid valve

9 = Blow-by

10 = Check valve

11 = Outlet

12 = Controller

Low-pressure oxygen (O₂) enters through the inlet (1). Its quality is crucial for booster performance and must meet ISO 8573-1:2010 Class 2:2:1 standards. The strainer (2) removes large particles from the pipeline. It only filters out coarse impurities and should not be used as a regular filter. Once the booster is ready, the controller (12) signals the solenoid valve (3) to open, allowing O₂ into the pump block (5). During the piston’s downward stroke, O₂ is drawn in; on the upward stroke, it’s compressed. Compression may occur in one or two stages depending on the required outlet pressure.

Some O₂ leaks past the piston into the crankcase during compression. This is known as blow by (9).

As compression raises the O₂ temperature, the cooler (6) reduces it to meet application requirements. When demand drops to the VSD’s turndown limit, the regulation valve (7) opens to recycle excess O₂ back to the inlet, ensuring stable operation. The check valve (10) allows high-pressure O₂ to exit the booster while preventing backflow. When the booster stops, the controller (12) activates the solenoid valve (8) to vent remaining compressed O₂.

Throughout the process, the controller (12) manages start-up, shutdown, pressure regulation, and system protection, continuously monitoring performance.