Dual plate check valves, also known as double disc or butterfly check valves, are a type of check valve characterized by their compact design and efficient operation.

Design and Construction:

• • Dual plate check valves consist of two semicircular plates or discs that are mounted on a hinge pin within a single body. The plates are designed to open in response to forward flow, allowing fluid to pass through the valve.
• • When flow stops or reverses, the plates close under the influence of gravity and flow pressure, preventing backflow.
• • The hinge pin allows the plates to swing freely, providing low-pressure drop and efficient operation.

Materials of Construction:

• • Dual plate check valves are available in a variety of materials to suit different application requirements, including carbon steel, stainless steel, ductile iron, bronze, and exotic alloys.
• • The choice of materials depends on factors such as the fluid being handled, temperature, pressure, and corrosion resistance requirements.

Standards and Certifications:

• • Dual plate check valves are manufactured according to industry standards and specifications such as API (American Petroleum Institute), ASME (American Society of Mechanical Engineers), ASTM (American Society for Testing and Materials), ANSI (American National Standards Institute), and others.
• • They may also meet specific regulatory requirements or certifications for use in critical applications or hazardous environments.

Forged steel check valves are a type of check valve constructed using forged steel components, making them robust and suitable for high-pressure and high-temperature applications.

Design and Construction:

• • Forged steel check valves are available in various designs, including swing check valves and lift check valves. Swing check valves feature a hinged disc that swings open in the direction of flow and closes under the influence of gravity or reverse flow.
• • Forged steel check valves are constructed using forged steel components for enhanced strength and durability.
• • The main components typically include a body, bonnet, disc (or flap), seat, and hinge pin. The valve body and bonnet are forged from steel to withstand high pressures, while the disc is designed to open and close to allow or prevent flow.
• • Lift check valves utilize a disc or piston that lifts from the seat to allow flow and settles back to close off flow when pressure decreases or reverses.

Materials of Construction:

• • Forged steel check valves are typically made from materials such as carbon steel, stainless steel, or alloy steel.
• • The choice of material depends on factors such as the fluid being handled, temperature, pressure, corrosion resistance requirements, and compatibility with other system components.

Standards and Certifications:

• • Forged steel check valves are manufactured in accordance with industry standards and specifications such as API (American Petroleum Institute), ASME (American Society of Mechanical Engineers), ASTM (American Society for Testing and Materials), ANSI (American National Standards Institute), and others.
• • They may also meet specific regulatory requirements or certifications for use in critical applications or hazardous environments.

Design and Construction:

• • Pressure sealed check valves are available in various designs, including swing check valves and lift check valves. Swing check valves feature a hinged disc that swings open in the direction of flow and closes under the influence of gravity or reverse flow.
• • Lift check valves utilize a disc or piston that lifts from the seat to allow flow and settles back to close off flow when pressure decreases or reverses.
• • Pressure sealed check valves are constructed with robust materials and a unique pressure seal bonnet design to withstand extreme operating conditions. The main components typically include a body, bonnet, disc (or flap), seat, and hinge pin.
• • The body and bonnet are designed with pressure seal arrangements, such as threaded, welded, or bolted connections, to ensure a tight seal under high pressure. The disc is engineered to open and close smoothly to allow or prevent flow, while the seat provides a sealing surface for the disc.

Materials of Construction:

• • Pressure sealed check valves are typically made from high-quality materials such as carbon steel, stainless steel, alloy steel, or other specialized alloys capable of withstanding high pressures and temperatures.
• • The choice of material depends on factors such as the fluid being handled, temperature, pressure, corrosion resistance requirements, and compatibility with other system components.

Standards and Certifications:

• • Pressure sealed check valves are manufactured in accordance with industry standards and specifications such as API (American Petroleum Institute), ASME (American Society of Mechanical Engineers), ASTM (American Society for Testing and Materials), ANSI (American National Standards Institute), and others.
• • They may also meet specific regulatory requirements or certifications for use in critical applications or hazardous environments.

Swing check valves are a type of check valve characterized by a hinged disc or flap that swings open to allow flow in one direction and closes to prevent backflow.

Design and Construction:

• • Swing check valves consist of a body with inlet and outlet ports, a hinged disc, and a hinge pin or shaft. The disc is attached to the hinge pin and swings freely within the body to allow or prevent flow.
• • When forward flow occurs, the disc swings open, allowing fluid to pass through. When flow stops or reverses, the disc swings closed under the influence of gravity or reverse flow, preventing backflow.

Applications:

• • Swing check valves are used in a wide range of industries and applications where backflow prevention is critical.
• • They are commonly installed in pipelines, pump discharge lines, steam lines, and process equipment to prevent reverse flow and protect equipment and processes from damage.

Materials of Construction:

• • Swing check valves are available in various materials to suit different application requirements, including carbon steel, stainless steel, bronze, cast iron, and exotic alloys.
• • The choice of material depends on factors such as the fluid being handled, temperature, pressure, corrosion resistance requirements, and compatibility with other system components.

Swing flex check valves, also known as swing-flex or swing-flo check valves, are specialized types of swing check valves designed to provide efficient flow control while minimizing the risk of slamming and water hammer.

Design and Construction:

• Swing flex check valves feature a unique flexible disc or flap design that allows for smooth operation and reduced wear compared to traditional swing check valves.
• The flexibility of the disc also helps to minimize the effects of water hammer and slamming during operation.
• The flexible disc is typically made of elastomeric materials such as rubber or synthetic polymers, providing a tight seal against the valve seat to prevent backflow.

Applications:

• Swing flex check valves are commonly used in applications where reliable backflow prevention and efficient flow control are required.
• They are suitable for use in pipelines, pump discharge lines, sewage systems, stormwater drainage systems, and other fluid handling applications.

Materials of Construction:

• Swing flex check valves are available in a variety of materials to suit different application requirements, including cast iron, ductile iron, carbon steel, stainless steel, and various elastomeric materials for the disc.
• The choice of material depends on factors such as the fluid being handled, temperature, pressure, corrosion resistance requirements, and compatibility with other system components.