Pump Curve For Air And Gas Handling

Simplify pump selection with vacuum and pressure pump performance curves for hazardous and safe area applications.


A pump curve is a graphical depiction illustrating a pump's operational performance. Its significance is paramount when dealing with gases. At ADI, our unwavering commitment to furnishing pressure-vacuum flow pump curves underscores our dedication to precision, performance, and reliability; it's a commitment to accuracy and dependability. We firmly believe that streamlining pump selection empowers you to match your needs. Our pump curves transcend mere charts; they serve as guiding tools for achieving success in the handling of air and gases.


ADI tailors solutions meticulously to align seamlessly with your specific needs, whether in hazardous or safe areas. Exploring these comprehensive tools allows you to transform your pump selection journey into a seamless, informed, and confident experience. Say goodbye to uncertainties and welcome precision. Explore our combination curves to navigate your pump selection journey with ease.

What Is a Pump Curve?

A pump curve is a visual representation that clarifies the performance capabilities of a pump within a range of rated flow and pressure at different operating points. Proficiency in interpreting a pump curve chart is essential for identifying the full spectrum of operational points for a pump. Engineers and professionals consider this knowledge invaluable when choosing the optimal pump tailored to a specific application.


Why Pump Performance Curves Matter?

Understanding the importance of pump curves is crucial for making informed decisions about pump selection. Here's why these curves hold such value:

  • Tailored Insights: ADI's pump curves provide essential guidance for precisely selecting and operating pumps in specific applications, offering critical data to optimize both efficiency and performance. Similarly, our combination curves offer tailor-made insights into the performance of our pumps across a range of conditions, accounting for both vacuum and pressure scenarios.
  • Streamlined Selection: These combination curves simplify the process of selecting the right pump by presenting a holistic view of performance in real-world situations. This means you can make choices with confidence, knowing how the pump will perform under different conditions.
  • Efficiency Optimization: By studying ADI's pump curves, you can pinpoint the ideal operating points that yield the highest efficiency, contributing to minimizing energy consumption and reducing operating costs. Similarly, we emphasize mastering the interpretation of pump curve charts for effective pump selection and operation, playing a pivotal role in extending the pump's lifespan by preventing issues such as overloading or operation beyond its optimal range.

In summary, combination curves are indispensable tools provided by ADI that empower you to make precise and efficient choices in pump selection, ensuring performance excellence and cost-effectiveness in your industrial gas handling applications.

Understanding Pump Efficiency Curves

Introducing Combination Curves

In the diaphragm pump industry, Standard Performance Curves are conventionally employed, resembling a typical bell-shaped normal distribution curve. These curves effectively illustrate either pressure or vacuum individually. Despite their utility in testing pump performance, they primarily cater to scenarios involving either pressure or vacuum, rather than both concurrently. However, in many gas sampling applications, a combination of vacuum and pressure is prevalent, rendering the traditional curves less suitable.


Graph 1: Representation of a standard performance curve for an ADI R-Series pump
Graph 1: Representation of a standard performance curve for an ADI R-Series pump



Recognizing this discrepancy, ADI has introduced a novel solution known as Combination Curves, colloquially referred to as Combo Curves. Unlike Standard Performance Curves, Combo Curves provide a comprehensive representation of a diaphragm pump's pressure and flow capacity, accommodating both vacuum and pressure simultaneously. By embracing this nuanced approach, ADI enhances the applicability of diaphragm pumps in diverse gas sampling contexts, ensuring a more accurate and insightful assessment of their performance under varied conditions.

The creation of Combination Curves involves plotting the flow rate against outlet pressure while maintaining a constant vacuum at the inlet. This process is executed for different vacuum levels, revealing how the flow rate is influenced by the combination of a vacuum on the pump inlet and pressure on the pump outlet.


How to Read Pump Curves

Accurately interpreting a pump curve chart helps identify potential operating points for a pump, aiding informed selections tailored to specific applications.


Graph 1: Representation of a combination curve for ADI R224 series pumps
Graph 2: Representation of a combination curve for ADI R224 series pumps



ADI’s combination curves reveal how adjusting the outlet pressure while maintaining a constant inlet vacuum impacts the flow rate. Typically the pressure is shown on the x-axis and the flow rate on the y-axis.

Various points on the chart result from maintaining a constant inlet vacuum. Flow rate is commonly measured in liters per minute (l/min), while gas pump outlet pressure is typically measured in pounds per square inch (PSI). The constant vacuum at the pump's inlet is quantified in inches of mercury (inHg). These curves, meticulously generated in increments of 5 InHg, provide a detailed understanding of the pump's behavior under varying conditions, contributing to a more robust evaluation of its performance in real-world applications.


How to Utilize ADI’s Pump and Combination Curves

At ADI, we stand out by providing a complete set of resources for pump selection. We create these combination curves to cover different vacuum conditions and show how changes in both inlet vacuum and outlet pressure impact the flow rate. This unique feature makes selecting the right pump simpler, offering valuable insights for informed decisions.

Leveraging ADI's Performance Pump Curves and Combination Curves:

  1. Specify Your Requirements: Begin by identifying the specific vacuum and pressure conditions relevant to your application.
  2. Consult ADI's Curves: Utilize our extensive curve library to find the curves that align with your conditions, helping you identify the most suitable pump model for your specific needs.
  3. Optimize Your Choice: Fine-tune your selection based on efficiency and other application-specific factors. This step ensures you choose a pump that aligns perfectly with your performance and cost-efficiency goals.

ADI's commitment to providing these valuable resources stems from our dedication to enhancing your gas sampling and handling applications. Our aim is to simplify the selection process and help you make well-informed choices. These tools empower you to optimize your pump selection, potentially reducing energy consumption and operating costs, all while ensuring the best performance for your applications.

How Do You Test A Pump For A Combination Curve?

Testing a pump for a combination curve involves a series of precise steps to ensure its performance aligns with the desired parameters. Here's a step-by-step guide:

  1. Gauge Installation: Start by removing the pump from the system and installing a closed pressure or vacuum gauge onto the pump. Once in place, measure the vacuum or pressure and compare it to the minimum requirements outlined in the operating instructions.
  2. Setup for Diaphragm Pumps: When creating combination curves, specifically for diaphragm pumps, connect the pump to a vacuum line and then link it to a pressure line. Initiate the pump under open flow conditions, which typically means atmospheric pressure.
  3. Gradual Adjustments: After the pump is operational, start making gradual adjustments:
    1. Slowly close the inlet line until you achieve the desired vacuum level.
    2. Gradually close the outlet pressure line to reach the desired pressure. Be prepared to observe changes in the pump's inlet vacuum as this occurs.
  4. Fine-Tuning: Slowly open the inlet vacuum line to bring the vacuum back to the desired level. It may require repeating these adjustments several times until the pump's pressure and vacuum levels stabilize.
  5. Flow Rate Recording: Finally, record the flow rate using the pump's outlet line. This measurement encapsulates the combination of vacuum, pressure, and flow values, providing valuable data for your combination curve.

By following these meticulous steps, you can accurately test a pump for a combination curve, ensuring it meets the desired performance criteria. This information is essential for optimizing your pump's efficiency and suitability for your application, potentially reducing energy consumption and operating costs.

Need Expert Advice?

Do you have inquiries or require expert guidance in ADI’s pump technology? Our team of dedicated professionals is at your service, prepared to assist you in finding the ideal pump tailored to your specific application. Feel free to contact ADI today, and let us enhance your pumping solutions.