Specification

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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.

Figure 1

2. How do you use a Swing Check Valve?

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:

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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: 

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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: 

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• 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.

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If you are looking for more details, kindly visit Globe Valve.

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.

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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 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:

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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.

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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.

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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?

Maintenance

Introduction

Gate valves, butterfly valves and check valves such as gate valves, butterfly valves and check valves are used throughout many industries to regulate the flow of liquids and gases. One of them is swing check valve which is mostly employed in preventing backflow. You might be wondering, &#;What is a swing check valve, and why is it so commonly used?&#; This ultimate article will take you through basic things about swing check valves such as how they function, types available and where they are applied across different sectors.

What Is a Swing Check Valve?

Swing check valves are one of the types of check valves which allow fluid to flow in only one direction but automatically prevent backflow. They function by having a hinged valve disc that swings open with forward flow and closes when the flow changes direction, thus ensuring unidirectional movement. Swing checks are employed in various applications where stopping reverse flow is critical, such as piping systems, wastewater treatment and firefighting equipment. Due to their ease and dependability, they have been favored across multiple sectors.

Next, we will discuss further the operation principle of swing check valves that makes them work well in regulating fluid flow.

How Does a Swing Check Valve Work?

A swing check valve works by the use of fluid dynamics and pressure differences. When the fluid flow starts from the inlet side, the upstream pressure acts on the disc and makes it to open. This motion enables the fluid to flow through with ease and therefore ensuring the low pressure drop across the valve. In cases where the flow direction has to be maintained in a particular direction, such as in wastewater systems or sewage systems, this feature works very well.

When the flow pressure reduces or there is a flow reversal, the disc returns to the closed position to avoid back flow. This automatic closure is important in avoiding water hammering, a situation where a flow of fluid is suddenly stopped and this results in a pressure wave that may harm the piping system. When the right type of check valve is chosen, especially those that are high pressure or have unique modification requirements, the swing check valve provides protection against such problems. This design coupled with a strong valve body and a well designed valve seat guarantees the best performance of the valve regardless of the pressure difference.

Swing check valves are different from other types of check valves like ball valves or spring check valves in the direction of the flow control. Their design does not allow for flow pressure disruptions, which is useful in wastewater applications where flow reversal must be quickly resolved. Thus, the knowledge of the dynamics of swing check valve operation will help engineers to control the effects of water hammer and prolong the service life of the systems.

Key Components of a Swing Check Valve

The swing check valve is made up of several parts that are very vital in the proper functioning of the valve. Let&#;s break down each key part:

• Valve Body: Valve body is the outer shell of the valve that contains all the internal parts of the valve. It is usually constructed of heavy materials such as stainless steel, cast iron or bronze depending on the nature of the media being regulated. The valve body gives the necessary support and also shields the internal parts from external conditions such as corrosion or mechanical impacts. Its material selection is vital in order to guarantee that the valve will be able to handle the pressure and temperature range that it will be exposed to in the system.
• Valve Disc: The valve disc is the part of the valve that rotates in a manner that opens or closes depending on the direction of the flow of the fluid. The valve disc is usually manufactured from stainless steel or other materials that are resistant to corrosion since the disc is always in contact with the fluid passing through the valve.
• Valve Seat: Valve seat is the internal component of the valve body on which the valve disc comes to rest when the valve is in the closed position. It has a very important function of sealing the valve to avoid back flow. The valve seat is often made from a hard wearing material such as metal or a composite to ensure that it does not wear out quickly and to ensure that the valve seat is a tight fit. The quality and precision of the valve seat are critical to the performance of the valve because any defects in the valve seat will cause leakage and poor performance.
• Hinge Mechanism: The hinge mechanism is used to join the valve disc with the valve body so that the disc can open and close. This part is vital for the movement of the valve and is expected to endure the cycles of operation throughout the life of the valve. The hinge is usually made of the same material as the valve disc or the valve body to ensure strength and corrosion resistance. The position of the hinge and the design of the hinge are critical in the operation of the valve and the amount of wear on the valve disc and the valve seat.

Types of Swing Check Valves: Top-Hinged vs. Tilting Disc

It is important to know the difference between the top-hinged and the tilting disc when choosing a swing check valve for your system. These two types both provide the fundamental function of enabling the passage of fluids in one direction only and preventing backflow but they have different operational features and therefore are appropriate for use in different applications.

Top-Hinged Swing Check Valves

Top-hinged swing check valves are of conventional design. The hinge is situated at the top of the valve body and links it to its disc part of the valve. Therefore, this disc opens when the inlet pressure increases and it closes by gravity with the help of back flow pressure if the flow pressure decreases or becomes negative. This design is suitable for low pressure systems where pressure drop is of essence. However, because there is a hinge on which its disc rests, there is always a slight delay in closing, which may lead to water hammering under certain conditions. It is often used in horizontal flow or where basic valve operation and low cost are expected through high usage.

Tilting Disc Swing Check Valves

On the other hand, tilting disc swing check valves are designed for more accurate flow control. Unlike other check valves that fully open and close, tilting disc swing check valves have discs mounted on pivot points, which allows them to tilt. This design helps them respond faster to flow reversal, reducing the risk of water hammering. As a result, they offer better control over fluid flow. Tilting disc valves are often used in sanitary systems or wastewater treatment plants. The tilting action allows for a more gradual closure, which minimizes pressure wave formation and enhances the longevity of the valve. While these valves are more expensive due to their complex construction, they provide superior prevention of reverse flows. They are especially suitable for applications that require high pressure.

Below is a chart showcasing some key parameters of swing check valves from the manufacturer Dombor. For those interested in more detailed specifications, you can explore the full swing check valve list here for comprehensive information.

Advantages and Disadvantages of Swing Check Valves

&#;Swing check valves are used in many industries because of the following benefits. &#;&#;One of the major ones is their simplicity as they run on their own depending on the flow conditions and hence do not need much or any manipulation or power from the outside. &#;&#;Therefore, they are very reliable in applications where reliability of the equipment is paramount. &#;&#;In addition, swing check valves are used in various types of media such as liquid, gas, and even semi-solid in sewerage systems and wastewater treatment. &#;

&#;However, there are some disadvantages that are associated with these valves. &#;&#;For example, swing check valve may be vulnerable to water hammer effect which is a shock wave that occurs when a valve shuts down rapidly across the pipe system. &#;&#;If left unattended to this can cause damages. &#;&#;In addition, although swing check valves are very useful in avoiding backflow, they are not as useful in high pressure conditions that are suitable for other types of check valves such as spring check valves or silent check valves. &#;&#;Knowing these positives and negatives will assist you in deciding whether you should use a swing check valve for your application requirements.

Common Applications of Swing Check Valves Across Industries

Swing check valves are widely used in many industries due to their function of avoiding back flow and ensuring the fluid flow in one direction only. Due to their flexibility, they can be used in several important applications.

Swing check valves are widely used in water and wastewater treatment plants, and are one of the most popular types of check valves. In these systems, it is important to maintain a flow direction in order to avoid contamination and to have the system work properly. For instance, in a municipal wastewater treatment plant, swing check valves assist in controlling the pressure of the flow and the back flow that may cause pollution of clean water sources. These valves can operate with very low pressure drops and this makes them suitable for such applications where low pressure is usually experienced.

Another important use is in pump systems especially in flood control systems. Swing check valves are used on the suction side of the pumps to ensure that water does not flow back to the source when the pump is turned off. This is important in avoiding water hammering, which is destructive to the piping and other parts. These valves are very important especially in areas that are near the sea or river where flooding is common to prevent back flow of water into the system which may damage infrastructure and the environment.

Swing check valves are also used in the oil and gas industry. In these high pressure environments, the valves are essential in avoiding the back flow of oil or gas, which may lead to build up of pressure. For example, in offshore drilling platforms, swing check valves are used to control the flow direction of the extracted resources for safety and functionality.

These examples show how swing check valves are used in different industries such as water treatment, oil extraction and many others. They are very useful in both high and low pressure systems because of their ability to offer flow control and back flow prevention under various circumstances.

Installation and Maintenance Best Practices

Swing check valves should be installed and maintained correctly to guarantee that they will work effectively in the long run. When installing these valves, one has to ensure that the flow is in the right direction and the position of the valve. For example, in horizontal flows, the valve should be fitted with the hinge at the top to help gravity in closing the valve. In vertical upward flow, the valve should be placed in such a manner that the flow assists in the opening of the valve and the stopping of the flow closes the valve.

Maintenance entails periodic checks on the valve disc, valve seat and hinge mechanism to determine their condition in as far as presence of debris and wear is concerned. These components can wear out or get damaged and this will lead to leakage or failure of the valve to shut as it is supposed to. It is also necessary to observe the system for water hammer and this can be controlled by changing the position of the valve or incorporating other measures of control. By adhering to these best practices, you will be able to optimize the performance of your swing check valve and integrate it into your system efficiently.

Choosing the Right Swing Check Valve for Your Application

It is important to grasp the advantages of swing check valves to be able to apply them in the various industries effectively and safely. Dombor, the No. 1 industrial valve manufacturer in China since , has over 3,000 projects of experience especially in oil and gas and chemical industries. This guarantees that you receive the best solution for your needs since they are professionals. Are you ready to improve the dependability of your system? Call Dombor today to get the right swing check valve for your needs.