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They allow the passage of fluid (liquid or gas) in a single direction. They also aid the maintenance process of systems and avoid the issue of backflow.


Swing Top


1. What is an Swing Ball Valve?

A swing check valve operation depends on gravity and reverses flow control. The valve simple device is designed to allow fluids to flow in one way direction. The greater the flow velocity and head pressure possibility, the greater the valve closing force would be. It is an automatic valve that opens with forwarding flow and closes with reverse flow. When there is a pressure flow through the valve connection to the valve body, it opens the valve disc, and while any reversal of flow will close the valve automatically. The valve operation will vary depending on the type of swing check valve mechanism and specification.

Swing Check Valve

Figure 1

2. How do you use a Swing Check Valve?

ansi 150# cast steel flange end swing check valves

ANSI 150# Cast Steel Flange End Swing Check Valves

A basic swing check valve consists of a valve body, bonnet, gasket, arm, bolt, and disc that is connected to the hinge. When there is external pressure, the disc swings away from the valve seat to allow flow in the forward direction inside the swing check valve body and returns to the valve seat when the upstream flow is stopped to prevent backflow in the system. The disc in a valve body is unguided as it fully opens or closes. There are several disc and seat designs to serve the requirement of different fluids applications. The valve is fully closed when the flow reaches zero.


Swing check valve structural features:


  • The valve structure is simple and compact.

  • The valve flap closes quickly which makes the water hammer when the working pressure falls below the cracking pressure, which is the minimum pressure to open a swing check valve.

  • The valve design is sensitive to a small change in pressure.

  • It provides a good sealing performance.

  • Reliable valve selection for long-term application.

3. Can you use a Swing Check Valve vertically?

The swing check valve is an important component part of pipeline installation where the flow can only go in one direction. The swing check valve can be installed vertically or horizontally. However, it is most common to install a swing check valve on a horizontal pipeline. Swing check valve connects on vertical pipeline does not affect the installation process. The critical part is the installer needs to ensure the stamped arrow points upwards. It enables the flow through the valve body to travel upwards and prevent gravity from pulling it back.


A swing check valve is mounted with a disc that swings on a hinge and the disc swings off the seat to allow fluids to flow through and the disc swings back onto the seat to block the backflow when fluids stopped. The disc weight has an impact on the shut-off characteristics of the valve.

4. How to avoid the Swing Check Valve problem?

Water hammer or hydraulic shock is a common occurrence with swing check valves which rely on the reversal of fluid flow to close quickly. It refers to an internal pressure increase due to a sudden stop or change in the same direction of the fluid traveling through the valve body. The frequently repeated closing of the disc may cause the disc to detach from the swing arm on the valve body. It happened occurs when a valve is closed suddenly at the end of the pipeline. The fluid slams into the now-closed valve and creates a hydraulic shock wave that resonates throughout the system.


Water hammer caused system fault and there are several outcomes are possible which includes the following:

  1. Pipeline collapse

  2. Failure of other components such as pressure gauge, flanges, etc.

  3. Leaks at pipe fittings and joints

  4. Damage to the product that is processed

To avoid water hammer happened to swing check valve, here are the tips: 

1. Proper system design

It is essential to understand the project design and specific needs before fabrication. The following installation preparation will help to lower the velocity of the fluid in the pipe: 

  • Use the shorter pipe lengths.

  • Add fitting like elbow and expansion loops to process the piping system. Water hammer is related to the fluid speed, and with the elbow, it reduces the influence of pressure waves. 

  • Arrange the primary pipes in loops that supply shorter and smaller run-out pipes branches. It helps to lower velocity flows for both sides.

2. Proper system programming

Water hammer occurs when a fluid is expedited or slowed by valve position changes. When the system is running at low pressure and the pressure change is slow, the water hammer is practically undetectable. However, when the fluids move quickly inside the system application, the internal pressure created from turning pump components on or off causes a significant water hammer effect. The extreme pressure changes through proper system programming work to eliminate the risk. The processing system helps to minimize the potential for a water hammer.

3. Proper system training

Adequate or pilot training teaches installers the importance of operating the valve correctly to minimize the effects of a water hammer. Good pipeline control practices such as start-up and shutdown operation procedures ensure the system works efficiently and safely.

threaded end ss316 swing check valves

Threaded End SS316 Swing Check Valves

threaded end brass swing check valves

Threaded End Brass Swing Check Valves

5. The preparation before installing a Swing Check Valve

The process of how to install a swing check valve is important to ensure the valve performs at high capacity.


Here are the steps to take note of:

Step 1:

Select the check valve size by measuring the piping outer diameter size before you purchase a swing check valve. Measure the pipe size as it will be attached to the valve connector. Check the valve material and connection. The common material is stainless steel SS316, cast steel, or brass. The standard connection types are threaded end or flange end. 

Step 2:

Ensure the valve internal is free and clean. If there is a minor scrap stuck inside the valve body, it could potentially cause the flap to get stuck and prevent all fluid from flowing. By doing this step, you can save time to avoid repairing jobs needed during installation time.

Step 3:

Check the external edges especially the flange end connection. Select the valve free of uneven edges or scratches that could ensure valve sealing correctly. The valve is working properly.

Step 4:

Confirm placement of valve. The valve has an arrow that indicates the flow direction. Identify the system flow direction and place it in the appropriate direction before installation.

6. What is the maintenance step of Swing Check Valve?


Install: Swing




Attach the swing check valve onto the pipeline. To create the connection, you can either use hand tightening or simply put a flange together with bolts and nuts.

JIS 10K SS316 Flange End Swing Check Valve


Run the swing check valve testing by activates your pipeline system and make sure the fluid flows smoothly inside the valve body.

ansi 150# ss316 swing check valves

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