Different Types of Check Valves and Their Applications

In order to ensure the efficient and safe operation of the piping system, it is essential to select the right type of check valve. Check valves play a central role in preventing backflow and protecting water hammers. Different types of check valves are designed for different flow conditions and performance requirements, which makes choosing the best check valve for a particular project complicated. This article will compare various check valve types and their application examples to help you choose the most suitable type.

Different Types of Check Valves and Their Applications

When choosing the right valve for your system, it is important to understand the various check valve types and their specific applications. The characteristics and benefits of each type of check valve are different, making each type suitable for specific environments. The following sections discuss five common types of check valves and their typical uses to help you decide which valve type is best for your project needs.

Lift Check Valve

Lift check valves allow fluid to flow in one direction by lifting the disc from the seat. When the flow stops or reverses, the disc falls back onto the seat, preventing backflow. These valves are typically used in systems with high fluid pressures and relatively clean fluids. Lift check valves range in size from 1/2 "to 8" for a variety of pipe sizes. They are capable of handling medium to high flow fluids, ensuring stable operation under high flow pressures.

Lift check valves are popular for their superior performance in high pressure applications. Their gravity-assisted closing mechanism ensures a reliable seal that preserves system integrity. Low maintenance requirements help reduce long-term operating costs. However, they may not be suitable for fluids containing suspended particles, as particles may interfere with the normal position of the disc. In addition, the high opening pressure makes it unsuitable for low pressure differential systems.

Lift check valves are widely used in the oil and gas industry, where they often have to deal with high-pressure environments. Chemical processing plants and plants in high-pressure steam and water networks also use lift check valves to ensure safe and efficient fluid flow in harsh environments.

Swing Check Valve

Swing check valves control fluid flow by swinging the disc on the hinge or shaft. They are suitable for low flow and low drop systems. Swing check valves range in size from 2 "to 30" and can be adapted to different pipe diameters, especially for systems with low to moderate flow rates and low cracking pressures.

A big advantage of swing check valves is their simple design, which makes operation and maintenance easier, thus improving the long-term reliability of the system. They are particularly suitable for larger diameter pipes because the lower pressure drop improves overall system efficiency. In high-speed systems, however, they can be affected by water hammers and are slower to respond to countercurrents.

Swing check valves are widely used in water and wastewater treatment plants because they help maintain a steady flow direction. They are also commonly found in pumping stations and boiler systems as a key component for reliable operation.

Double Plate Check Valve

Double-plate check valves, also known as sandwich check valves, have two discs that switch according to the direction of flow. Their small size and light weight make them ideal for space-constrained environments. Double-plate check valves range in size from 2 "to 24" and are capable of operating under different flow conditions, with rupture pressures between lift and swing check valves.

The compact design and lightness of the double-plate check valve help to save space in systems where installation space is limited. They have low pressure drop, reducing energy consumption and improving flow efficiency. This valve is suitable for gas, liquid and steam and other media. However, their maintenance requirements can be high and they are not suitable for fluids with high particle content.

Double-plate check valves are commonly found in HVAC systems, chemical processing, and Marine applications, where space utilization and reliability are highly demanding.

Non-slam Check Valve

The non-slam check valve is designed for smooth and quiet closing. A spring mechanism is usually used to assist in closing, making it more responsive to countercurrent. They range in size from 1/2 "to 24" and are suitable for both low and high flow systems. Most non-slam check valves have a low to moderate break pressure, allowing them to respond quickly to changes in flow direction.

Non-slam check valves minimize or eliminate water hammers, which can cause serious damage to plumbing and associated equipment. In addition, their quietness and rapid response to changes in flow direction improve their applicability in delicate operations. However, its design is complex, maintenance requirements are high, and initial costs may be high.

Non-slam check valves are suitable for pumping stations, tall building water supply systems, and other applications where hydraulic shock can interrupt operation or damage equipment.

Tilt Disc Check Valve

Tilt disc The disc of a check valve can be tilted to allow fluid to flow in one direction and return to its original position when the pressure is removed. It is designed with low pressure drop and is able to handle different flow rates and pressures. Tilt disc check valves range in size from 2 "to 30" for a variety of applications. Its low rupture pressure makes it ideal for low pressure systems, ensuring smooth and efficient operation.

One of the main advantages of tilt disc check valves is their versatility. They can handle different flow conditions and are designed to be durable with less maintenance. Therefore, users can improve system efficiency by reducing maintenance costs. However, tilt disc check valves typically cost more than swing check valves and may need to be properly installed for optimal performance.

Tilt disc check valves are widely used in areas such as water distribution systems, industrial processes and power production because they demonstrate reliability in these diverse applications.

Key Considerations when Choosing a Check Valve

When choosing the right check valve, there are several factors to consider for the best results. Here are the main factors to consider:

Flow Conditions

It is important to understand the flow conditions in the system, including velocity, pressure, and the possibility of backflow. Different types of check valves are suitable for different flow conditions. For example, lift check valves are suitable for high pressure systems, while swing check valves are suitable for systems with low flow rates and low drops. Knowing the flow conditions helps to select the valve with the best performance and reliability.

Material Compatibility

The compatibility of the valve's material with the handling fluid is critical to prevent corrosion and improve valve life. Stainless steel is widely used because of its corrosion resistance and versatility. Depending on the fluid and environment, other materials such as brass or PVC can be selected.

Opening Pressure

Opening pressure refers to the minimum pressure required to open the valve. The opening pressure of the valve should match the operating conditions of the system. Low opening pressure valves are suitable for low pressure differential systems, while high opening pressure valves are suitable for high pressure systems. Select the appropriate opening pressure to ensure that the valve will work properly under the expected system conditions.

Size and Weight

The size and weight of the valve will affect the design and installation of the system. Small, lightweight valves such as double-plate check valves are suitable for areas with limited space. Make sure the valves don't take up too much space or add weight to the system to ensure the structure is strong and easy to install.

Maintenance Requirements

It is necessary to consider the maintenance needs of the valve, and not all check valves are maintained at the same frequency. For example, a non-slam check valve may require regular maintenance and cleaning. Understanding maintenance requirements can help you budget and improve system reliability.

Application Specific Requirements

Consider the specific requirements of your application. Some industries and applications may have other special requirements. For example, tilt disc check valves are widely used in industrial processes and power production because they are flexible and can operate under different flow conditions. This helps increase the efficiency and durability of the valve to meet the needs of your application.

Conclusion

This paper introduces the main features and applications of lift type, swing type, double plate type, non-punch type and tilt disc type check valves. Some important factors to consider when selecting a check valve are discussed, such as flow conditions, material compatibility, opening pressure, size, and maintenance requirements. Hopefully, this guide will help you choose the best check valve for your business.