A Comparative Study of High-Temperature And High-Pressure Performance Between Lift Check Valves And Swing Check Valves

Understanding Lift Check Valves

Structure and Operation

Lift check valves consist of a valve body, a valve seat, and a movable disc. The disc moves vertically along the centerline of the valve body, allowing fluid to flow through when the pressure is sufficient. When the fluid flow stops or reverses, the disc drops back onto the seat, preventing backflow. This mechanism is similar to that of a globe valve, providing precise control over fluid flow.

High-Temperature and High-Pressure Performance

• Material Selection: Lift check valves often use materials like stainless steel, carbon steel, and alloy steel for their valve bodies and discs. These materials are chosen for their strength and resistance to high temperatures and pressures. For example, the valve seat and disc may be coated with Stellite, a cobalt-based hard alloy, to enhance wear resistance and durability.

• Sealing Performance: Lift check valves offer excellent sealing performance due to the tight contact between the disc and the seat. This makes them suitable for applications requiring high sealing reliability.

• Pressure Drop: Due to the vertical movement of the disc, lift check valves generally have a higher pressure drop compared to swing check valves. This is because the fluid must change direction to pass through the valve, resulting in increased resistance.

• Operating Conditions: Lift check valves are typically used in high-pressure applications where precise control and reliable sealing are crucial. They are commonly found in steam systems, hydraulic systems, and chemical processing plants.

Understanding Swing Check Valves

Structure and Operation

Swing check valves feature a circular disc that pivots around a hinge or a shaft. When fluid flows in the forward direction, the disc swings open, allowing fluid to pass through. When the flow stops or reverses, the disc swings back to its closed position, blocking the flow. This design allows for a more streamlined flow path compared to lift check valves.

High-Temperature and High-Pressure Performance

• Material Selection: Swing check valves are also constructed from materials like stainless steel, carbon steel, and alloy steel. The valve seat and disc may be coated with hard alloys or other wear-resistant materials to enhance durability and performance in high-temperature and high-pressure environments.

• Sealing Performance: While swing check valves provide good sealing, they generally have a slightly lower sealing efficiency compared to lift check valves. This is due to the nature of the disc's movement and the potential for slight misalignment during closure.

• Pressure Drop: Swing check valves have a lower pressure drop compared to lift check valves. The streamlined flow path allows fluid to pass through with minimal resistance, making them suitable for applications where flow efficiency is critical.

• Operating Conditions: Swing check valves are commonly used in large-diameter pipelines and systems where low flow resistance is important. They are often found in water supply systems, oil pipelines, and other applications with high flow rates.

Comparative Analysis

Sealing Performance

Application Suitability