How to Address Excessive Pressure Drop in the Piping of a PSA Oxygen Generation System

In a PSA oxygen generation system, as the compressed air flows through the piping, it encounters resistance from pipes, valves, fittings, and other components, resulting in a pressure loss - known as a pressure drop. The magnitude of this pressure drop is not fixed; it varies depending on the system design, equipment type, and operating conditions. Generally, for small to medium-sized PSA oxygen generation systems, the normal pressure drop typically falls within the range of 0.01 to 0.2 MPa.

If the system experiences an excessive pressure drop, it indicates an underlying issue. The root causes often involve piping leaks, blockages, or valve malfunctions. When troubleshooting this problem, examine the following key areas:

Check for Piping Leaks

• Soapy Water Leak Detection: Apply a soapy water solution to pipe welds, connection points, and other joints to identify any visible leaks. Once leaks are confirmed, perform targeted repairs or replace the affected piping sections.

• Pressure Testing: Use specialized pressure testing equipment to conduct a comprehensive pressure test on the entire piping system. Monitor for any pressure decay to pinpoint the exact location and severity of the leak, and subsequently carry out the necessary repairs.

Clear Piping Blockages

• Physical Cleaning: For blockages caused by the accumulation of impurities, dust, or debris, employ tools such as gas purging or pipe augers to clear the obstruction.

• Chemical Cleaning: If the inner walls of the piping are contaminated with stubborn deposits - such as oil residue or scale - chemical cleaning agents may be used to remove them. The selection of cleaning agents and the execution of the cleaning process should ideally be performed by qualified professionals to prevent the cleaning procedure from corroding the piping.

Inspect Valves and Fittings

• Check Valve Status: Inspect automatic valves, switching valves, and similar components to ensure they open and close smoothly without any sticking or jamming. If a valve fails to open fully, it increases local flow resistance within the piping, leading to an excessive pressure drop. Therefore, if any sticking is detected, the affected valve must be repaired or replaced.

• Check Fitting Connections: Verify that fittings - such as elbows, tees, and couplings - are securely connected and show no signs of looseness or deformation. Loose connections can result in gas leaks, thereby increasing the pressure drop; conversely, deformed fittings can alter the geometry of the piping, disrupting gas flow and also contributing to pressure loss. If any issues are identified, the fittings must be tightened or replaced.

Optimize Piping Layout and Design

• Reduce the Number of Elbows: An excessive number of elbows leads to increased pressure drop. During the design and installation phases, the piping layout should be optimized whenever possible to minimize the use of elbows, thereby ensuring a straighter and smoother flow path.

• Adjust Pipe Diameter: Select an appropriate pipe diameter based on the specific requirements for gas flow rate and velocity. If the pipe diameter is too small, the gas velocity will increase, leading to greater frictional resistance and a consequent rise in pressure drop. Therefore, it is essential to use appropriately sized piping to mitigate pressure drop.

Inspect Equipment Operating Parameters

• Air Compressor Operating Status: Verify that the air compressor's discharge pressure and flow rate meet the specified requirements. Malfunctions within the air compressor can disrupt the gas supply to the entire system - potentially resulting in excessive pressure drop within the piping network.

• Other Equipment Parameters: Check the operating parameters of other system components - such as refrigerated dryers and filters - to ensure they are functioning normally. Abnormal operation of these devices can also contribute to pressure drop within the piping system.

Indeed, the timely detection, diagnosis, and resolution of excessive piping pressure drop are of paramount importance and absolutely critical for ensuring the stable and efficient operation of a PSA oxygen generation system.