Although wafer check valves and swing check valves serve the same functions—such as preventing backflow, enabling low-load pump startup, and reducing water hammer—they differ significantly in design standards, structural features, and areas of application. This article analyzes their differences across five key aspects to help users make more informed decisions when selecting a suitable valve type.

Difference 1: Design Standards

Wafer check valves are manufactured according to the following design standards:
• CJ/T 282-2008: Resilient Slow-Closing Butterfly Check Valve
• JB/T 5299-2022: Hydraulic-Controlled Butterfly Check Valve
• JB/T: Butterfly Pump Control Valve

In contrast, swing check valves follow these main standards:
• GB/T 12236-2008: Steel Swing Check Valves for Petroleum, Petrochemical, and Related Industries
• GB/T 13932-2016: Cast Iron Swing Check Valves
• API 6D-2021: International standard widely used in the oil and gas industry

It can be observed that wafer check valves are more commonly used in domestic municipal water systems, whereas swing check valves have broader global applicability, especially in demanding or high-standard working environments.

Difference 2: Distinct Structural Differences

The disc of a wafer (butterfly type) check valve is circular, with a pin shaft running through its center and positioned within the flow path. This results in a more compact design but can lead to increased flow resistance.

In contrast, the pin shaft of a swing check valve passes through the outer edge of the disc’s sealing surface and is located outside the flow path. This structural configuration allows the valve to operate more stably under medium to high pressure conditions.

Difference 3: Variation in the Use of Slow-Closing Structures

Due to their frequent use in large-diameter, low-pressure systems, butterfly check valves often feature slow-closing designs. The disc in such valves has greater movement inertia and is more susceptible to fluid impact, which can cause water hammer. To mitigate this, various slow-closing types are commonly used, such as:

• Hydraulic automatic control valves

• Dynamic flow check valves

• Hydraulic-controlled butterfly check valves

On the other hand, swing check valves are typically applied in medium and small-diameter pipelines (DN15–DN600), where slow-closing structures are less common. Only a few models, such as the HH44X, incorporate this design feature.

Difference 4: Differences in Application Conditions

Butterfly check valves are primarily used in water systems and are well-suited for low- to medium-pressure applications, such as water treatment and municipal supply and drainage systems.

In contrast, swing check valves offer a broader range of applications and can be used in low-, medium-, and high-pressure conditions. They are suitable for a wide variety of media, including:

• Water

• Steam

• Oil

• Chemical fluids

When it comes to material selection, swing check valves are available in a wide range of options—from cast iron and cast steel to stainless steel and special alloys—making them ideal for handling more complex and demanding operating environments.

Difference 5: Differences in Pipeline Connection Methods

Butterfly check valves, due to their typically large diameter sizes, primarily use flange connections, while some smaller diameter models employ wafer (or lug) connections.

In contrast, swing check valves offer a wider variety of connection methods, including:

• Threaded connections

• Flanged connections

• Wafer (or lug) connections

• Welded connections

• Clamp connections

This diversity in connection options makes swing check valves more flexible in installation, allowing them to better meet the demands of different piping system configurations.

Frequently Asked Questions (Q&A)

Q1: Are butterfly check valves suitable for high-pressure systems?

A: Generally, they are not recommended. Butterfly check valves are mainly used in low to medium pressure, large-diameter systems, and are less stable and reliable than swing check valves in high-pressure environments.

Q2: Why do butterfly check valves require a slow-closing (soft-close) design?

A: Because the valve disc is large and the opening/closing inertia is high, water hammer effects are easily generated. Therefore, most butterfly check valves are designed with a slow-closing mechanism to protect the system.

Q3: What working conditions are swing check valves suitable for?

A: Swing check valves are widely used for water, steam, oil, and corrosive media, especially in industrial applications requiring high sealing and pressure resistance.

Q4: Which type of check valve saves more installation space?

A: Butterfly check valves have a more compact structure and typically require less installation space, making them suitable for areas with limited space.

If you need help choosing the right check valve type for your specific application, please contact our technical team. We offer professional selection advice and customized solutions tailored to your needs.