Swing Check Valve: A Complete Guide

The use of check valves allows us to control fluid backflow, improving the efficiency of fluid systems. Swing check valves are widely used in fluid systems due to their unique advantages. This article will introduce swing check valves from several different perspectives, gradually unveiling their mysteries to assist you in selecting the right swing check valve.

What is a Swing Check Valve?

To understand what a swing check valve is, we first need to know what a check valve is. As the name suggests, a check valve is a type of valve that controls backflow. A swing check valve is a specific type of check valve that uses a swinging motion to control the backflow of fluid. This means it only allows fluid to flow in one specific direction, preventing reverse flow.

Types of Swing Check Valves

Wafer Swing Check Valve: This type of valve has a thin body design, with the disc mounted between two flanges. It controls the direction of fluid flow to ensure it flows in only one direction.

Tilting Disc Swing Check Valve: This is another type of swing check valve, featuring a tilting disc design. This allows it to respond faster than other swing check valves, enabling quick opening and closing to block fluid flow.

Y Swing Check Valve: Named for its Y-shaped design, this type of swing check valve is also used to control the direction of fluid flow.

Structure of Swing Check Valves

To truly understand a product, we need to look at its overall structure and internal components. This helps us gain a deeper insight into the product. From the following structural diagram, we can see that the appearance of swing check valves is similar to most check valves, but the real difference lies in their internal design.

A swing check valve typically consists of a hinge, a disc, a base, and sealing elements. Under normal conditions, the disc, aided by the weight of a lever, forms a closed unit with the base and sealing elements. When fluid flows in the designated direction, the external force acting on the disc creates a forward push. This breaks the closed state of the valve, causing the disc to move upward at an angle, instantly forming a passage for the fluid to pass through easily.

Conversely, when fluid tries to flow back through the check valve, the disc, already closed by gravity and leverage, forms a tight seal with the base and sealing elements. The backflow fluid also applies an additional force on the disc, making the seal even tighter. This simple yet clever design allows the swing check valve to prevent any fluid from flowing backward without manual intervention.

source：CNLD

Working Principle of Swing Check Valves

Once we understand the internal structure of swing check valves, we can visualize their operating state and working principle. These valves rely on the flow of fluid to push the disc, which is fixed on the hinge, to open or close.When fluid flows in the correct direction, the disc is pushed open, creating a passage. Conversely, when fluid tries to flow back, gravity and the reverse fluid pressure cause the disc to close perfectly against the base and sealing elements, blocking any backward movement.

This is the entire working principle of swing check valves: simple, efficient, and requiring no manual intervention, which helps save costs.

Materials of Swing Check Valves

Swing check valves can be made from various materials, including cast iron, carbon steel, stainless steel, brass, plastic, and alloys. The choice of material depends on the environment in which the valve will be used. Therefore, when selecting a swing check valve, it is important to consider factors such as the operating temperature, fluid characteristics, and working pressure.

Advantages and Disadvantages of Swing Check Valves

Advantages: The overall structure is simple, making operation easy and requiring no manual control. This helps save costs. The valve opens and closes based on gravity and the forward force of the fluid, resulting in low flow resistance within the pipeline and improving the overall performance of the system.

Disadvantages: The valve relies on its own weight to close, making it unsuitable for low-flow liquids. This can prevent the check valve from functioning effectively. Additionally, impacts and wear from the fluid can lead to poor sealing, requiring regular maintenance. Due to its design, it cannot be installed on inclined pipelines, which limits its application range.

Applications of Swing Check Valves

Water Supply and Drainage Systems: Due to their simple operation, swing check valves are commonly used in water supply and drainage systems to control the direction of liquid flow and prevent backflow.

Pump Pipelines: Because of their check valve properties, they are often installed at the outlet of pumps. This effectively prevents backflow that could damage the pump due to reverse pressure.

HVAC Systems: Swing check valves help control the direction of hot and cold air flow, meeting design requirements for heating, ventilation, and air conditioning (HVAC) systems. They prevent air from flowing backward, improving overall system efficiency.

Power Industry: They are typically used in turbine systems at power plants to control the direction of steam and water flow. This protects turbines from water hammer effects caused by reverse flow, which could lead to damage.

Installation of Swing Check Valves

To ensure that swing check valves function effectively, it is important to follow relevant requirements and standards during installation. When installing on horizontal sections, check that the direction of fluid flow matches the opening direction of the disc to allow smooth passage through the valve. For vertical installations, ensure that the disc opens upward and that the fluid flow can pass through easily; otherwise, the disc may not seal properly.

Finally, pay attention to details such as gaskets and bolts during the installation of the valve and pipeline. Adding gaskets between the flange and the valve can prevent fluid leakage, and bolts should meet the manufacturer’s specified standards to ensure a tight seal.

Maintenance of swing check valves

To sustain outstanding performance for an extended period of time, any part requires frequent maintenance and care in addition to excellent quality. When the swing check valve is operating properly, the fluid’s contact on the valve disc damages the valve disc, particularly the wear between the valve disc and the seal, causing the valve to become loose in the latter stages and failing to achieve the desired sealing effect. As a result, the swing check valve must be maintained on a regular basis, and the seal should be changed as soon as it becomes significantly worn.

Future Trend of Swing Check Valve

The swing check valve will certainly not end here. It will not stagnate, but will instead adapt and evolve in response to technological advancements and manufacturing requirements. Based on the previous development history, we may speculate about the swing check valve’s future development pattern.

Digital Intelligence: Most industries are currently evolving in this direction, adopting various cutting-edge technologies to provide intelligent functionalities to their goods, and the swing check valve is no exception. This is also a future growth trend, utilizing clever methods to ensure that the check valve is more precise.

Material update: Since the Industrial Revolution, materials science has been constantly evolving. We have been looking for high-strength, lightweight, corrosion-resistant, and wear-resistant materials. Using these novel materials to build swing check valves allows for less regular maintenance and part replacement in the future, saving money.

Noise: Noise pollution is unavoidable in every manufacturing environment, thus swing check valves will be improved in the future, employing new materials and technologies to decrease or eliminate noise during operation.

Environmental protection and energy saving: Environmental protection and energy saving are inseparable main themes. The development of any product must follow environmental protection, comply with relevant laws and regulations, and improve energy-saving performance to enhance the core competitiveness of the product.

Swing Check Valves from CNLX

Lixin Valve Group Co., Ltd. was established in 2000. It is a modern enterprise with four production bases that integrates research, development, production, sales, and service. Lixin has received ISO 9001, ISO 14001, and OHSAS 18001 certifications, as well as API 6D certification from the American Petroleum Institute, TUV certification, and CE certification.

Their swing check valves are highly sensitive to slight pressure changes, enhancing the sealing performance of the valve. These check valves feature a weighted disc that swings forward to allow media flow and then returns to its original position under gravity for a tight seal. The valves have a compact and simple overall structure, effectively preventing media overflow, making them ideal for high-pressure applications and easy to install.

Conclusion

By gaining a comprehensive understanding of the features of swing check valves, we can clearly recognize their applications across various industries and how to select the right swing check valve for our needs. Lixin Valve Group has a strict quality management system that ensures every product meets international standards. With its professional workshop and excellent mold casting capabilities, Lixin not only provides high-quality swing check valves but also offers solutions tailored to your specific requirements.