Axial Flow Check Valve: Structural Analysis and Applications

 
In industrial applications, axial flow check valves are essential fluid control devices designed to prevent backflow and ensure the proper operation of systems. Depending on the structure of the valve disc, axial flow check valves are primarily classified into two types: ring disc type and collar plate type. Each type has unique design features, performance characteristics, and application scenarios. This article provides a detailed analysis and comparison of these two types to assist users in selecting the most suitable valve for their needs.

Ring Disc Type Axial Flow Check Valve

 
The ring disc type axial flow check valve is a common choice for high-pressure and high-flow applications due to its unique structure and excellent performance. Its integral body design ensures reliable sealing while simplifying the structure, making it highly effective across various industrial applications. Below, we explore the specific advantages, performance characteristics, and suitable applications of the ring disc type axial flow check valve.

1. Structural Features

 
The ring disc type axial flow check valve features an integral body design with no external leakage points. The flow path inside the valve body is constructed with an internal wall and flow components arranged in an axisymmetric layout, often employing the Venturi principle to maintain high flow velocity within the flow path when the valve is closed. This design creates a pressure differential across the valve disc, promoting valve opening and stable medium transport.
 
The valve stem is designed to be longer, with a longer guide length and shorter opening and closing stroke, which helps maintain good alignment and operational stability. The valve disc, connected to the valve stem, acts as the primary moving and closing component and is typically designed as a single curved disc to reduce flow resistance and minimize impact on the seat during closure.

2. Performance and Advantages

 
The spring in this type of check valve is usually positioned behind the valve disc, allowing for a quick response to changes in medium flow and ensuring rapid valve closure to prevent backflow and protect pumps or compressors. The sealing structure typically combines metal and soft seals, which, while not achieving zero leakage, provides reliable performance.
 
The design of the ring disc type axial flow check valve ensures good pressure recovery after the medium flows through the valve, making it suitable for various medium transport needs. Its relatively simple structure and reliable key design make it well-suited for high-pressure and high-flow conditions. However, attention must be given to the durability of sealing components in low and high-temperature medium transport.

3. Application Scenarios

 
Due to its stable design and good flow performance, the ring disc type axial flow check valve is widely used in industries such as oil and gas, chemical processing, power generation, and metallurgy. It is suitable for transporting nearly all media except those containing high concentrations of particulate matter, such as mineral slurries. It is especially appropriate for use in large pump stations, compressor stations, and pipeline transport systems.

Collar Plate Type Axial Flow Check Valve

 
The collar plate type axial flow check valve, known for its unique dual-channel design, is particularly suited for applications requiring reduced weight and noise. This design allows for a more compact valve body and lowers operating noise levels. However, its flow capacity may be limited under high flow conditions. The following section delves into the structural features, performance advantages, and appropriate operating environments of the collar plate type axial flow check valve.

1. Structural Features

 
The collar plate type axial flow check valve also features an integral structure but is distinguished by its dual-flow channels: one external channel formed by the valve body and the disc with the flow guide, and one internal channel formed by the inner flow guide and the disc. This dual-channel design allows for a more compact valve body and effectively reduces operating noise.
 
The valve seat is designed with two sealing surfaces on the inner wall of the valve body and the front flow guide, creating the unique collar plate structure. The collar plate shape improves the disc's stress distribution, reducing thickness under high pressure and thus decreasing the overall weight of the valve.

2. Performance and Disadvantages

 
While the collar plate type axial flow check valve offers advantages in reducing weight and noise, its complex structure results in significantly reduced flow capacity, especially under high flow conditions. The internal flow guide and external channel can occupy a large portion of the flow area, leading to insufficient flow capacity.
 
Additionally, the floating nature of the collar plate and its support by only a few radial guide vanes can lead to potential damage to the guide vanes under high-pressure and large-diameter applications, affecting the valve's lifespan. The precision required for sealing surfaces increases manufacturing difficulty and cost.

3. Application Scenarios

 
The collar plate type axial flow check valve, due to its complex structure and flow capacity limitations, is more suitable for small-diameter and low-frequency operations. It is less ideal for high-pressure and high-flow environments, particularly for gas media with significant fluctuations. For low and high-temperature media transport, ensuring the suitability of the valve body material is necessary.

Conclusion and Suggestions

 
When selecting an axial flow check valve, users should consider their specific operational needs. The ring disc type axial flow check valve, with its simple structure and stable flow control, is ideal for high-pressure and high-flow environments, making it a preferred choice for most industrial applications. In contrast, the collar plate type axial flow check valve excels in weight reduction and noise reduction, making it suitable for small-diameter and low-frequency operations. By making an informed choice, users can enhance system performance, extend equipment lifespan, and optimize maintenance costs.