Differences among lift check valve, swing check valve, and butterfly check valve

Check valves are essential components in fluid systems, preventing backflow and ensuring unidirectional flow. Among them, lift check valves, swing check valves, and butterfly check valves serve similar functions but differ in structure, operation, and application.

1.Lift Check Valve

A lift check valve operates by allowing the valve disc to slide along the vertical centerline of the valve body. It is designed to be installed only in horizontal pipelines. In high-pressure and small-diameter applications, the disc may be a spherical shape.

The body structure of a lift check valve is similar to that of a globe valve, which results in a higher flow resistance coefficient.

Its design includes a guide sleeve in both the upper part of the disc and the lower part of the bonnet, allowing the disc to move freely within the sleeve.

When the medium flows forward, the disc opens due to the pressure of the fluid. When the flow stops, the disc falls back onto the valve seat due to its own weight, preventing backflow.

Straight-through lift check valves have their inlet and outlet perpendicular to the valve seat passage, whereas vertical lift check valves have the same direction for inlet, outlet, and seat passage, reducing flow resistance compared to the straight-through type.

Check Valve

2.Swing Check Valve

A swing check valve features a disc in the shape of a circular plate, which rotates around a pivot to open and close the passage. Due to its streamlined flow path, it offers lower flow resistance than a lift check valve.

It is suitable for large-diameter applications with low flow velocity and stable flow conditions but is not ideal for pulsating flow.

The sealing performance of a swing check valve is not as good as that of a lift check valve.

There are three types of swing check valves based on disc configuration:

Single-disc swing check valve

Double-disc swing check valve

Multi-disc swing check valve

These variations help reduce hydraulic impact when the flow stops or reverses.

butterfly valves

3.Butterfly Check Valve

The butterfly check valve has a structure similar to a butterfly valve, but unlike a butterfly valve, which requires external force to operate, a butterfly check valve functions automatically.

When the medium flows forward, the butterfly plates rotate around a pin to open, resembling the shape of a “>” symbol.

When the flow stops or reverses, the plates return to the valve seat due to gravity and backflow pressure, preventing reverse flow.

This type of check valve can be installed in both horizontal and vertical pipelines and is typically mounted in a wafer-style configuration.

The valve requires a short straight pipe section at the inlet and outlet to allow space for the discs to rotate.

Each type of check valve has its unique characteristics and advantages, making them suitable for different applications:

Lift check valves are ideal for high-pressure and small-diameter pipelines but have higher flow resistance.

Swing check valves are better suited for large-diameter pipelines with stable flow, offering lower resistance but poorer sealing performance.

Butterfly check valves are compact, easy to install, and suitable for both horizontal and vertical installations, making them a versatile choice.

Understanding these differences helps in selecting the right check valve for optimal system performance and efficiency. Email:sales@haihaogroup.com