Zero Velocity Valves
Zero Velocity Valves:
A spring loaded self-actuated zero velocity valve (ZVV) is designed to prevent water hammer by breaking the energy of the returning water column just when its forward velocity reduces to near zero.
A ZVV is designed to close gradually, which allows it to break the energy of the returning water column and prevent water hammer. As the flow of water slows down and approaches zero velocity, the valve begins to close. This slows the water down even further and gradually stops the flow. This is accomplished through the use of a spring-loaded mechanism that automatically closes the valve when the water flow slows down or stops.
When a fluid flow is suddenly stopped, the kinetic energy of the fluid is converted into pressure energy, which can cause the pipeline to vibrate or even rupture. By gradually closing the valve, a ZVV allows the kinetic energy of the fluid to dissipate gradually, preventing water hammer from occurring. This is achieved by using a special design that allows the valve to close gradually, rather than slamming shut all at once.
In addition to preventing water hammer, ZVVs can also be used to prevent backflow in a pipeline. When the fluid flow stops, the valve closes, preventing any backflow from occurring. This is particularly important in applications where backflow could contaminate the fluid or damage the pipeline.
Advantages of spring loaded self-actuated zero velocity valve:
Water hammer / Surge control: One of the primary advantages of this type of valve is its ability to control surges in water pipelines. The valve closes quickly and without slamming shut, which helps to prevent water hammer and other surge-related issues.
Non-slam closing: The valve is designed to close gradually, which helps to prevent damage to the pipeline and equipment. This makes it an ideal choice for applications where pipeline integrity is critical.
Energy efficiency: The valve is self-actuated, which means that it operates automatically without the need for external Power. This makes it ideal for use in remote locations or other situations where manual control is not practical.
Reliability: The spring-loaded mechanism used in the valve is highly reliable and requires minimal maintenance. This makes it a cost-effective solution for surge control in water pipelines.
Easy installation: The valve is easy to install and can be retrofitted into existing pipelines. This makes it a practical solution for controlling surges in older pipeline systems
Low maintenance: The valve is designed to operate for long periods of time with minimal maintenance, reducing downtime and repair costs.
Improved system efficiency: By reducing the risk of pipeline damage, a ZVV can help to maintain the efficiency of the pipeline system, improving its overall performance.
Increased safety: By preventing water hammer, a ZVV reduces the risk of accidents or injuries caused by pipeline failures.
MOC : Mild steel (MS)
Sizes : 100 mm - 3000 mm