What Are Check Valves And Where Are They Used?

Jul 22, 2023 | News


Check valves, also known as one-way valves, allow fluid flow in only one direction through a piping system. They open to permit forward flow and passively close to prevent reverse flow. With proper check valve selection, systems gain protection, maintain pressure differences, isolate sections, and ensure efficient pumping.

flange double door check valve

Check valves are crucial components in various industrial applications including:

• Pumps: To prevent backflow after the pump is switched off
• Compressors: To avoid reverse flow that can damage blades
• Boilers and Pressure Vessels: To stop system drainage
• Process Lines: To ensure one-way transfer between vessels and units
• Water Supply Lines: To prevent contamination from backflow

Overview Of Flange Double Door Check Valves

Flange double door check valve consists of a body with two closure plates or doors mounted internally on a hinge. As fluid enters the valve, the doors swing open allowing full bore unobstructed flow. When flow tries to reverse, the doors swiftly swing shut to block backflow. Double door check valves offer:

• Full pipe diameter flow for minimal pressure drop
• Ability to handle fibrous materials without clogging
• Easy inspection and maintenance access to the internal doors
• Options like dual plates for critical services needing redundancy

Lift Check Valves And Their Working

China Lift check valve contains a disc and hinge assembly attached externally to the valve body. As forward flow starts, the disc lifts up to allow passage through the valve. A spring ensures the disc shuts promptly when flow reverses. Key features of lift check valves:

• Compact and light design with external moving parts
• Lower cracking pressure for high sensitivity
• Springs customized to pressure conditions
• Suitable for vertical or horizontal installation

Overview Of Single Disc Wafer Check Valve

Wafer check valves have a single circular closure disc held between two body flanges. The disc seals against the upstream seat. Their key properties:

• Thin wafer body designed for between-flange installation
• No body cavity minimizes fluid hold up and contamination
• Often used in high purity pharmaceutical applications
• Suitable for sizes up to 8″ and pressure ratings up to 300 psi

Check Valve Selection Considerations

Proper sizing along with choosing rugged designs from reputable manufacturers ensures reliable, long-lasting check valve performance. To select the optimal check valve type, consider:

• Application pressure, temperature, and media characteristics
• Desired cracking pressure sensitivity
• Required check capacity and minimum pressure loss
• Vertical vs horizontal installation
• Frequency of inspection and maintenance needs
• Cost limitations and expected service life