Working Principle

The axial-flow check valve operates based on the pressure difference between the inlet and outlet ends. When the inlet pressure exceeds the sum of the outlet pressure and the spring force, the disc opens, allowing the medium to flow through the axial channel of the valve body. When the outlet pressure combined with the spring force becomes greater than the inlet pressure, the disc closes and remains shut, effectively preventing backflow.

Basic Information

• Model: General Type / Anti-Sulfur Type

• Pressure Rating: PN1.0–70.0 MPa (Class 150–2500)

• Size Range: DN15–1200 mm (NPS 1/2″–48″)

• End Connections: Flanged, Welded, Wafer, and Threaded

• Design Standards: API 6D, GB/T 21387

• Operation Mode: Automatic

• Materials: Carbon Steel, Austenitic Stainless Steel, Duplex Stainless Steel, and Other Alloys (e.g., Inconel 625, Incoloy 825)

Structural Features

• Shock Absorption Design: Equipped with a damping spring to avoid direct impact between the disc and the valve body during opening, thus reducing vibration and noise compared to conventional check valves.

• Sealing Structure: The valve seat adopts a combined sealing structure with hard and soft seals, offering noise reduction, shock absorption, and ease of on-site maintenance.

• Axial Shuttle Design: The unique axial-flow shuttle structure ensures low flow resistance, high flow coefficient, and compact dimensions.

• Disc Design: The disc is lightweight, reducing friction on the guiding surface and enabling quick return to the seat. The small mass and low inertia allow the disc to travel a short distance and gently contact the valve seat, preserving the sealing surface and preventing damage.

Performance Advantages

• Fast Opening and Closing: Compared with swing-type and wafer-type check valves, the axial-flow design has a shorter travel distance, especially for large-diameter valves, enabling rapid shutoff and effectively preventing reverse flow.

• Excellent Sealing Performance: The lightweight, low-inertia disc closes with minimal impact on the valve seat, significantly reducing seal surface damage and leakage.

• Low Fluid Resistance: The internal structure features a Venturi design, allowing the medium to flow in a streamlined manner, minimizing pressure loss and achieving low resistance.

• Low Vibration, Low Noise, and Anti-Water Hammer: Due to slow reverse flow and spring-assisted closure, there is no impact during opening or closing, effectively reducing mechanical vibration, noise, and water hammer.

Application Fields

• Oil & Gas Industry: Widely used in long-distance oil and gas pipeline systems, especially in key positions such as large ethylene plant compressors.

• Chemical Industry: Used to control the flow direction of chemical fluids, suitable for pipelines carrying oil, gas, water slurries, and H₂S+CO₂ acidic and corrosive media to prevent accidents.

• Power Industry: Commonly used in steam systems, condensate systems, boiler feed pumps, cooling towers, water service recirculators, river intakes, and renewable energy systems.

• Water Supply and Drainage Systems: Effectively prevents backflow in pipelines, ensuring safe and reliable water supply, suitable for water treatment plants, transmission systems, drinking water, and raw water.

• Refining and Petrochemical Industry: Applied to control media such as hydrogen, cracked gases, steam, crude oil, ethylene, and propylene, as well as steam and CO₂ injection systems and oil/gas gathering systems.

• Nuclear Industry: Key equipment in first-loop systems such as passive core cooling systems, steam generators, and spent fuel pool cooling systems.

• Marine and Offshore Engineering: Ensures safe system operation by controlling and preventing fluid backflow.

• Clean Energy Field: Used in systems such as wind and solar power generation to control fluid flow and enhance overall system efficiency.

Natural Gas Internal Gathering                Natural gas treatment plant

Class2500 2 1/2” Anti-Sulfur Type          PN10.0MPa DN300 General Type

Selection Considerations

• Nominal Diameter Selection: Choose the appropriate valve diameter based on fluid conditions to avoid continuous vibration of the disc and other moving components, which may lead to premature wear, noise, or unstable operation.

• Spring Stiffness Coefficient: Adjusting the spring stiffness changes the valve’s closing speed and dynamic characteristics. However, excessive spring force increases steady-state pressure loss, which is not energy-efficient.

• Operating Conditions: Select the appropriate disc structure and materials based on different operating conditions, such as medium type, pressure, temperature, and flow rate, to ensure optimal performance and reliability of the axial-flow check valve.