What Is a Pulsation Dampener

Pulsation dampeners are essential components in fluid handling systems designed to minimize pressure fluctuations and ensure optimal performance. This comprehensive article explores the causes and risks of fluid pulsations, the working principles of pulsation dampeners, and their various types and applications.

How Pulsation Occurs in Pumping Systems

Pulsation in pumping systems occurs due to the reciprocating nature of positive displacement pumps, such as diaphragm pumps, piston pumps, and peristaltic pumps. During the discharge stroke, the pump generates a pulse of fluid, causing pressure variations in the system.

Risks Deriving from Fluid Pulsations

Fluid pulsations pose several risks to pumping systems:

1. Excessive vibration: Pressure fluctuations can cause pipe rattle and vibration, leading to damage to pipe welds and piping runs.
2. Water hammer: Sudden pressure spikes, known as water hammer, can result in severe damage to pipes, valves, and instrumentation.
3. Reduced equipment lifespan: The constant stress caused by pressure pulsations can shorten the lifespan of pumps, valves, and other components.
4. Inefficient operation: Pulsating flows can decrease pump efficiency and affect the accuracy of flow metering devices.

What Is a Pulsation Dampener

A pulsation dampener is a device designed to minimize pressure fluctuations in fluid handling systems. It acts as a shock absorber, absorbing excess energy during pressure spikes and releasing it during pressure troughs. This process helps to maintain a steady flow rate and reduces the negative effects of fluid pulsations on the system.

How Does Pulsation Dampener Work

Pulsation dampeners work by providing a cushion of compressible gas or a flexible bladder that absorbs and releases energy as the fluid pressure fluctuates. The dampener is typically installed near the pump discharge, where it can effectively dampen pressure pulses before they propagate through the system.

As the pump generates a pressure spike, the dampener’s compressible gas or flexible bladder expands, absorbing the excess pressure. During pressure troughs, the compressed gas or bladder releases the stored energy, maintaining a more consistent pressure in the system.

Types of Pulsation Dampeners

Active Pulsation Dampener

Active pulsation dampeners use an external energy source, such as compressed air, to actively counteract pressure fluctuations. They continuously monitor the system pressure and adjust the dampening effect accordingly. Active dampeners are more complex and expensive than passive dampeners but offer superior performance in demanding applications.

Passive Pulsation Dampeners

Passive pulsation dampeners rely on the inherent properties of the dampening device to absorb and release energy without external intervention.

Gas-Charged Dampeners

Gas-charged dampeners, also known as bladder dampeners, consist of a pressure vessel divided into two chambers by a flexible bladder. One chamber contains a compressed gas, while the other chamber is connected to the fluid system. As the fluid pressure increases, the bladder compresses the gas, absorbing the excess energy. When the pressure decreases, the compressed gas expands, releasing the stored energy back into the system.

In-Line Passive Pulsation Dampener

In-line passive pulsation dampeners, also known as inlet stabilizers, are installed directly in the fluid line. They typically consist of a small chamber with a compressible material, such as a spring-loaded piston or a rubber bladder. As the fluid pressure fluctuates, the compressible material absorbs and releases energy, dampening the pulsations.

Benefits of Pulsation Dampener

• Extends Pump Life: By reducing the mechanical stress on pumps caused by pressure fluctuations, pulsation dampeners help extend the lifespan of pumping equipment.
• Minimize Water Hammer Effects and Vibration: Pulsation dampeners effectively reduce water hammer and vibration, protecting pipes, valves, and instrumentation from damage.
• Reduces Pump Maintenance Costs: With reduced mechanical stress and vibration, pumps require less frequent maintenance, resulting in lower overall maintenance costs.
• Reduced Noise and Mechanical Stress on the System: Dampening pressure pulsations lead to quieter operation and less mechanical stress on the entire fluid handling system.
• Protection of Pipes, Valves, and Instrumentation from Vibration and Damage: By minimizing vibration and pressure spikes, pulsation dampeners protect critical components from damage, extending their lifespan.
• Smoother Flow Rate and Reduced Pressure Fluctuations: Pulsation dampeners help maintain a more consistent flow rate and pressure, improving the overall performance of the fluid handling system.
• Improved Metering Accuracy and Pump Efficiency: With reduced pulsations, flow metering devices can provide more accurate readings, and pumps can operate more efficiently.
• Improved Discharge Pressure Control: Pulsation dampeners help maintain a more stable discharge pressure, enhancing the control and performance of the pumping system.
• Prevent Cavitation: By minimizing pressure fluctuations, pulsation dampeners can help prevent cavitation, which can cause damage to pumps and other components.
• Enhance Npsh (Net Positive Suction Head): Pulsation dampeners can improve NPSH by reducing pressure fluctuations at the pump inlet, minimizing the risk of cavitation and ensuring proper pump operation.

Application of Pulsation Dampers

Pulsation dampeners are widely used in various industries and applications, including:

• Chemical processing: Pulsation dampeners are essential in chemical processing plants to protect equipment from damage caused by pressure fluctuations and ensure accurate dosing of chemicals.
• Water treatment: In water treatment facilities, pulsation dampeners help maintain consistent flow rates and pressure, improving the efficiency of filtration and disinfection processes.
• Oil and gas: Pulsation dampeners are used in oil and gas applications to protect pipelines, valves, and instrumentation from the damaging effects of pressure pulsations.
• Pharmaceuticals: In pharmaceutical manufacturing, pulsation dampeners ensure precise dosing and protect sensitive equipment from damage caused by pressure fluctuations.
• Food and beverage: Pulsation dampeners are used in food and beverage processing to maintain consistent flow rates and pressure, ensuring product quality and protecting equipment from damage.

Faqs

What Is the Difference between a Surge Suppressor and a Pulsation Dampener

Surge suppressors and pulsation dampeners are both designed to protect fluid handling systems from pressure fluctuations, but they serve different purposes.

Surge suppressors are used to protect against sudden, high-magnitude pressure spikes, such as those caused by water hammers. In contrast, pulsation dampeners are designed to minimize the constant, lower-magnitude pressure fluctuations caused by the reciprocating action of positive displacement pumps.

What Is the Difference Between a Suction Dampener and a Pulsation Dampener

Suction dampeners and pulsation dampeners are both used to minimize pressure fluctuations in fluid handling systems, but they are installed at different locations.

Suction dampeners, also known as inlet stabilizers, are installed at the pump inlet to minimize pressure fluctuations and protect the pump from cavitation. Pulsation dampeners, on the other hand, are typically installed at the pump discharge to dampen pressure pulsations and protect downstream components from damage.

Conclusion

Pulsation dampeners are critical components in fluid handling systems designed to minimize pressure fluctuations and protect equipment from damage. By understanding the causes and risks of fluid pulsations, the working principles of pulsation dampeners, and their various types and applications, engineers and operators can select the most appropriate dampening solution for their specific needs.