Types of Check Valve
Any piping system needs to regulate fluid direction and stop reversal of fluid and need check valves. These automatic valves need to open and close based on changes in system pressure. With so many varieties available in the market, the system’s pressure, temperature, fluid properties, and space available all come into picture.
Speciality Valve has a vast range of check valves to suit the requirements of various industries such as power plants, chemical processing, water treatment, oil & gas, and so on. The definitions, applications, and functionality of the most widely used and advanced check valve types will all be discussed in this blog.
A swing check valve contains a hinged disc that swings open during forward flow and closes during reverse flow.
Function:
The valve prevents backflow by automatically closing the disc because of reverse pressure. It is ideally suited for horizontal use.
Applications:
- Water and wastewater systems
- Oil and gas pipelines
- Fire protection systems
- General-purpose fluid services
Also known as a wafer check valve, this type consists of two spring-loaded plates that swing on a central hinge pin to allow flow.
Function:
The plates open in forward flow and close rapidly in reverse flow to minimize water hammer.
Applications:
- Chemical and petrochemical plants
- Power generation
- HVAC systems
- High-pressure water piping
The valve is forged out of steel and hence suited for high-temperature and high-pressure applications.
Function:
It provides one-way flow and blocks reverse flow of fluid, typically utilized in aggressive systems because of its strength.
Applications:
- Steam and high-pressure piping
- Oil refineries
- Power generation plants
- High-temperature services
An adapted swing check valve that is made to close softly and stop slamming due to reverse flow.
Function:
It has a spring-loaded or damped mechanism which retards the closing action, minimizing water hammer.
Applications:
- Pump discharge lines
- Chilled water systems
- Water distribution networks
The valve uses a disc that lifts vertically off the seat in forward flow and returns to close the reverse flow.
Function:
It provides tight shut-off and is suitable for fluids under uniform high pressure.
Applications:
- Boiler feed lines
- High-pressure gas systems
- Chemical dosing systems
- Steam applications
6. Pressure Seal Swing Check Valve
High-pressure swing check valve with pressure-sealing bonnet configuration to handle very high pressure.
Function:
It has sealing performance enhancement with rising internal pressure and is therefore ideal for severe high-pressure service.
Applications:
- Superheated steam plants
- Thermal power generation plants
- High-pressure gas transmission system
- High-energy piping systems
It is a small valve which is a single plate or disc that swings open on flow and closes under back pressure.
Function:
It is space-conserving style of swing check valve and suit well in heavy duty area-constricted installing facilities.
Applications:
- Piping of small area industrial setup
- Systems for water supply
- Equipment on skids
- Chemical industry
It is fitted with tilting disc, which pivots on flow in fluid’s forward direction and softly tilts in return direction to shut during back flow.
Function:
It facilitates smoother and prompt movement as compared to normal swing check valves and reduces pressure drop.
Applications:
- Continuous running flow systems
- Cooling water systems
- Pump discharge lines
- Condensate return systems
Differences Between Check Valve Types
The choice of the right check valve is based on a clear understanding of their differences. Below is an explanation of how these valves differ in design, operation, and proper applications.
- Swing check valves are prevalent due to their simple design and are applicable for low-pressure horizontal flow systems.
- Dual plate check valves save space and minimize water hammer and, therefore, are a suitable choice for high-pressure applications with limited space.
- Steel forged check valves are specially made with strength in mind and are wanted in high-pressure, high-temperature applications like steam or chemical systems.
- Non-slam swing check valves solve a large operating issue—water hammer—by allowing slow closure, thereby being well suited for pump discharge lines.
- Lift check valves provide an even closer seal, especially with steady flow and pressure but are otherwise limited to horizontal mounting.
- Pressure seal swing check valves are a step ahead in terms of managing pressure, thanks to their pressure-assisted bonnet seals that improve sealing effectiveness with rising pressure.
- Single plate check valves, being compact, are applicable for small systems where space is limited.
- Lastly, tilting disc check valves provide smooth and rapid action and are suited to continuous flow systems due to low turbulence and good shut-off characteristics.
Based on Design Mechanism:
- Swing: Hinged disc opens/closes
- Dual Plate: Two spring-loaded plates open
- Forged Steel: Tough body for rugged conditions
- Non-Slam Swing: Spring or dampened closure to prevent slamming
- Lift: Disc lifts vertically with flow
- Pressure Seal Swing: Bonnet seal tightens under pressure
- Single Plate: Single thin swinging disc
- Tilting Disc: Disc tilts on axis for rapid response
Based on Optimal Applications:
- Swing: Water, oil, and gas general services
- Dual Plate: Power, chemical, compact systems
- Forged Steel: Refinery, steam, high-temperature pipes
- Non-Slam Swing: Chilled water, pump discharge
- Lift: Boiler feeds, high-pressure gas/steam
- Pressure Seal Swing: Superheated steam, power generation
- Single Plate: Small spaces, small pipes, small skids
- Tilting Disc: Continuous flow applications, condensate systems
Based on Performance Features:
- Low pressure best suited by: Single Plate, Swing
- Most appropriate for high pressure: Pressure Seal Swing, Forged Steel
- Less likely to cause water hammer: Tilting Disc, Dual Plate, Non-Slam
- Closes tightly: Lift, Tilting Disc
- Relatively small in size: Single Plate, Dual Plate
Each style of check valve possesses its own benefits dependent on system requirements like pressure, temperature, available space, and flow characteristics. From the traditional swing check valves to advanced pressure-seal and tilting disc designs, understanding each will assist with offering safe and cost-effective fluid system design.
At Speciality Valves, we offer a full line of industrial, commercial, and utility check valves. Our products are designed using top-grade materials and expert engineering to deliver performance and durability under the toughest conditions.
Having trouble finding the right check valve? Contact Speciality Valves today for expert advice and high-quality valve solutions.
