What are Brass Check Valves?

A brass check valve allows fluid to flow in a single direction. This prevents fluid from flowing in the opposite direction, which could contaminate or damage other components. Check valves function autonomously and do not require manual operation. Most available varieties have a small spring to close the valve, and medium forward pressure opens the valve. Note that a minimum pressure is required to release the valve (typically called the cracking pressure). These valves’ housings are made of brass. Yet, it is a cost-effective alternative to stainless steel for numerous applications.

Brass Housing

As a housing material, brass is used. Brass is a copper-zinc alloy with excellent mechanical properties. Brass check valves are known for their resilience. It can be used with potable water, gas, mineral lubricants, compressed air, and other non-aggressive media. However, due to the risk of dezincification, they cannot be used with saline or distilled water. Dezincification diminishes the mechanical strength of brass. It removes zinc from the alloy, resulting in a porous structure.

Types of Brass Check Valve

• Swing check valve
• Spring check valve

Spring Check Valve Vs. Swing Check Valve: Difference

What is a Spring Check Valve?

A type of check valve that permits fluid flow in a single direction while preventing backflow in the opposite direction. It is made primarily of brass, bronze, and stainless steel, resistant to corrosion. It involves the application of water or other non-corrosive fluids. The valve uses a spring mechanism. It provides the force to maintain the valve closed and prevent reverse flow. When fluid streams in the required direction, the pressure lifts the valve off its seat, allowing passage. However, when the flow direction reverses or stops, the spring pushes the valve back onto its seat. It blocks any backflow.

What are Swing Check Valves? 

In swing check valves, a flapper swings away to enable fluid or gas to flow forward. When it is appropriate to stop the flow, the flapper will return to its seat, automatically closing the valve as the system pressure drops. The high discharge capacity of swing check valves makes them stand out. These devices require a swaying action to function. Yet, their application is restricted to horizontal or upward-flowing vertical currents.

Swing Check Valve Vs. Spring Check Valve: Body Structure

Brass Swing Check Valve

The body design of a brass swing check valve typically consists of a compact and robust structure. It is commonly made from high-quality brass material, providing durability and corrosion resistance. The valve body features a cylindrical shape with threaded or flanged connections at its ends. It allows for easy installation in a pipeline system.

The swing check valve’s body incorporates a hinged disc or flap, which swings open and closes freely to control fluid or gas flow. The disc is typically made of brass or another compatible material and is attached to the valve body using a hinge mechanism. The disc swings open when the fluid or gas flows in the desired direction, allowing the medium to pass through. If there is a reversal in flow, the disc swings back into place, effectively blocking the flow and preventing backflow.

Body Structure of Spring Check Valve

Typically, it involves a cylindrical or tubular body with inlet and outlet ports. The valve body is cast iron, stainless steel, or brass depending on the application and control fluid.

Inside the valve body, a movable disc or flap acts as the check valve’s closing element. The disc is hinged or mounted on a pin or shaft. It allows it to move freely in response to fluid flow. A spring is attached to the disc. This provides force to maintain the valve closed without fluid pressure.

When fluid flows in the required direction, the pressure lifts the disc against the spring force. It allows the fluid to pass through the valve. Yet, when the flow reverses or stops, the spring pushes the disc back into its closed position. It prevents backward flow or backflow.

Spring Vs. Swing Check Valve: Working

How Swing Check Valves Works?

The disc of an inline swing check valve rotates on a hinge. The disc rests on the valve seal on the inlet side when the valve is closed. When the pressure of the media entering the valve exceeds the valve’s fracture pressure, the disc rises. Yet, the valve opens, and media can flow through. When the inlet pressure decreases, the valve closes to prevent downstream backflow.

How Spring Check Valves Works?

The basic working principle of a spring check valve involves the movement of a disc pushed against a seat by a spring. When the flow of fluid or gas is in the required direction, the fluid pressure lifts the disc off the seat. It allows the flow to pass through the valve unobstructed. The spring remains compressed during this process. When the flow direction tries to reverse, the pressure of the fluid pushes against the disc or ball, causing it to be forced against the seat. The spring then acts as a closing force, pressing the disc or ball firmly against the seat to create a tight seal and prevent backflow. The spring provides the resistance to keep the valve closed, ensuring that flow can only occur in one direction.

Brass Spring Check Valve Vs. Swing Check Valve: Temperature

Brass Spring Check Valve: Working temperature

In most cases, brass spring check valves can handle temperatures ranging from -20°C to 120°C (-4°F to 248°F). Always consult the manufacturer’s specifications for the specific valve. It helps to determine its recommended working temperature range.

Brass Swing Check Valve: Working Temperature

Brass and bronze swing check valves are suitable for various temperatures. Both brass and bronze are known for their thermal conductivity and high-temperature resistance.

Brass swing check valves typically have a temperature range of -20°C to 180°C (-4°F to 356°F), making them suitable for a variety of applications.

Bronze swing check valves, on the other hand, can handle even higher temperatures. They generally have a temperature range of -20°C to 232°C (-4°F to 450°F). This range makes them suitable for severe environments.

Spring Vs. Swing Check Valve: Materials

The kinds of pressure and materials that spring and swing check valves need are constructed from different materials. This material must withstand the severe conditions of an application. Various factors influence the material selection process for swing and spring check valves. These are the

• type of media
• pressure
• level of corrosion
• temperature

The amount of wear the valve will experience, and the cost of the final item are factors in the selection of materials. Yet, certain resilient materials are more expensive than others.

Bronze

Many characteristics of bronze make it an excellent material for fabricating check valves. It has high ductility to prevent fracture. It is resistant to corrosion and has a low price.

Ductile Iron

Iron’s availability and low price make it an ideal material for producing spring and swing check valves. It has a high abrasion resistance. Yet, it has low corrosion resistance.

Brass

Swing and spring check valves of brass can withstand extreme temperatures and pressures. They can be shaped and configured to fit any check valve and are less expensive than steel. Check valves made of brass are compatible with copper, brass, plastic, aluminum, and welded steel.

Stainless Steel

Swing and spring check valves are frequently manufactured from stainless steel. Its many characteristics, including its resistance to corrosion and oxidation, make it an ideal material for a wide range of check valve applications.

Connections for Spring and Swing Check Valves

They are connecting swing and spring check valves to a pipeline in numerous ways. Leakage prevention is essential for connecting the valve and the pipeline properly. Multiple connection methods include flanged, threaded, welded, sweat, and press.

Each of the numerous connection types ensures a secure connection between the swing or spring check valve and the piping system. Choosing the proper method of connection is crucial for effectively operating the valves.

Connections:

Threaded Connections

Threaded connections are the most fundamental method of connecting a valve to a conduit. It is used for small valves in low-pressure systems. As threaded suggests, they establish a secure connection by screwing onto a threaded pipe.

Press Fittings

Press connectors are a substitute for soldering and welding. A hydraulic device drives specially designed connectors onto the spring or swing valve to join it to the pipeline. When struck, a sealing element creates an even, smooth, and reliable connection. They are also known as press connect and crimping joints.

Flanged Connectors

Flanged connections are the most robust and can connect to any conduit system regardless of the pressure or size of the valve. They are equipped with two flanges bolted together at the inlet and one at the outflow.

Sweat Fitting

The swing or spring check valve openings for a sweat fitting are slightly larger than the piping. The solder is applied to seep into the space between the conduit and the valve fitting. Typically, this is conducted with copper piping.

Welded Connection

The purpose of a welded joint is to create a more secure, leak-free connection. This technique of connecting swing and spring valves is costlier. However, it ensures an exceptionally secure and exceptional connection between the valve and the pipeline. In areas where the absence of leaks is crucial, such as high-pressure and high-temperature conduit lines, welded connections are utilized.

Swing Vs. Spring Check Valve: Pros and Cons

Advantages and Disadvantages of Swing Check Valves

The utmost benefit of swing check valves is their low price, which makes them compatible with a wide range of project budgets. They also offer substantial discharge capacity. Since this valve cannot sustain downward vertical flow, it can only serve a limited range of systems. Also, water pressure is likely to be amplified by swing check valves.

Advantages and Disadvantages of Spring Check Valves

Since spring check valves can be used in vertical applications, they offer significantly more versatility than swing check valves. They are significantly more likely to be compatible with existing piping configurations. Depending on the choice of spring, this form of valve functions well in any flow orientation.

Spring check valves have the additional benefit of reducing water pressure. This device is known as a “silent check valve,” It reduces noise levels in applications where pendulum check valves could exacerbate the problem. Additional benefits of spring check valves include:

• Temperature resistance
• Positive sealing even below the cracking pressures

In contrast, spring check valves are typically costlier than swing check valves. Additionally, they have a reduced flow capacity.

Swing Check Valve Vs. Spring Check Valve: Applications

Application of Swing Check Valve

Swing check valves made of bronze are an essential component in many applications. It controls and regulates the passage of liquids, gases, or steam. Yet, these valves are commonly found in large-scale industrial applications. Here are some major prevalent applications for bronze swing check valves.

In water treatment systems, bronze swing check valves can be used. The valve avoids backflow and water contamination by controlling the flow’s direction. It can also be employed in irrigation systems. It prevents pumps from being overwhelmed by excessive pressure from over-pressurized areas upstream. Moreover, it can be installed on fire protection systems. This can prevent backflow when the water pressure fluctuates excessively.

Spring Check Valve Applications

Spring check valves are suitable for various water pipelines and system applications. This kind of valve prevents equipment from backflow-caused damage. Yet, it lowers the chance of system downtime and contamination. In addition, spring check valves can relieve system pressure. It creates a safer environment and ensures proper operation.

Maintenance of Spring Check Valves Vs. Swing Check Valves

Regular maintenance is the best way to ensure uninterrupted operation over the long term. It is suggested that valves be visually inspected for leaks within the first year. Yet, a complete maneuver cycle is performed every three months. This may lead to examining the valve and prevent scale formation when a valve operates under extreme conditions. More inspection is required.

Factors to Consider While Choosing the Spring and Swing Check Valve

When selecting a spring and swing check valve, essential factors are considered. It includes;

• application requirements (such as flow rate and pressure)
• type of fluid or gas being handled
• valve material compatibility
• valve size
• installation requirements

Can Swing Check Valves Be Repaired?

In most cases, swing check valves can be repaired. It can be done by replacing worn or damaged parts such as the disc or seat. However, the extent of repair ability depends on the valve design and spare parts.

What Are the Problems or Failures Associated with Spring Check Valves?

Various problems or failures with spring check valves. These include leakage, improper seating of the valve disc, spring failure, and flow restrictions. Regular inspection and maintenance can help prevent and address these issues.

What Is the Standard Size of the Swing Check Valve?

Swing Check Valve

Summary

• A spring check valve prevents reverse flow and ensures unidirectional flow. They have one inlet and outlet and must be oriented correctly for effective operation.
• Spring check valves contain a spring that holds the closing disc in place until sufficient pressure is applied. It causes the spring to collapse and transfer the disc from the pipe opening.
• A swing check valve only permits flow in one direction. It closes automatically when the fracture pressure drops. They are butterfly valve that covers the valve orifice with a disc.
• Swing and spring check valves are relied upon for their installation and low maintenance.