A Double diaphragm is a type of positive displacement pump that falls under the reciprocating pump type. See Figure 1.0.
Double Diaphragm Pumps Diagram

Figure 1.0

 

What Are Double Diaphragm Pumps?

An air operated double diaphragm pump is a type of positive displacement pump that uses compressed air to pump fluid through a liquid conveying system. The pump consists of two flexible diaphragms that move back and forth, drawing fluid into the pump and pushing it out. An air valve is used to control the flow of compressed air to the diaphragms, allowing for precise control of the pump's output.

Double diaphragm pumps are commonly used in a variety of industries, including chemical processing, food and beverage, and oil and gas. Their ability to handle viscous and abrasive fluids and their reliability and ease of maintenance make them a popular choice for many applications.

What Applications Use Double Diaphragm Pumps?

With their versatility, reliability, and efficiency, double diaphragm pumps are used in a wide range of applications across various industries. In the chemical industry, they are used for transferring chemicals, solvents, and corrosive liquids. In the food and beverage industry, they are used for transferring food products and liquids as they are hygienic and can handle viscous and shear sensitive fluids without damaging them. Likewise, double diaphragm pumps are applied in the medical and pharmaceutical industries to transfer sensitive fluids that require gentle and precise handling.

The application list is rounded off by the automotive and manufacturing industries, where diaphragm pumps are used for lubrication and fluid transfer. Overall, their ability to handle a wide range of fluids and their self-priming capabilities make them a popular choice for many industrial and liquid transfer applications.

How Does a Double Diaphragm Pump Operate?

When in operation, a double diaphragm pump is similar to a single diaphragm pump as it uses a plunger to move the fluid. The main difference is that a double diaphragm type has two diaphragms that work in tandem to increase the pump's ability to move fluid. This allows the pump to reach higher pressures and flow rates than a single diaphragm pump.

The pump displaces a fixed volume of liquid with each stroke of the piston. The piston is connected to the diaphragm, which is connected to the liquid in the pump chamber. When the piston moves down, it creates a vacuum on the upper side of the diaphragm, which sucks liquid into the pump chamber (suction phase, see Figure 2.0). The liquid is then forced out of the chamber when the piston moves up again (discharge phase, see Figure 3.0).

Double diaphragm Suction

Figure 2.0

Double diaphragm Discharge

Figure 3.0

What About Leak Detection and Double Diaphragm Pumps?

A double diaphragm does not automatically imply good leak detection. While most pumps with leak detection require double diaphragms, double diaphragms do not require leak detection. Some users prefer the double diaphragm design for its redundancy, but do not require any form of detection. Supplying double diaphragm without leak detection is also a means of meeting some specifications specified for tubular diaphragm designs.

What Are The Key Advantages of Double Diaphragm Pumps?

The key benefits of double diaphragms pump include:

  • Versatility 
    Double diaphragm pumps can handle a wide range of fluids, including corrosive and abrasive liquids, as well as viscous fluids with high solid content. They can also handle liquids with varying viscosities and consistencies.
  • Durability
    Double diaphragm pumps are built to withstand harsh environments and heavy use. They are designed with few moving parts, which reduces the chances of mechanical failure and increases the overall lifespan of the pump.
  • Efficiency
    They are highly efficient pumps and can move a large volume of fluid with minimal energy consumption. They are also designed to be self-priming pumps, which means they can start and stop easily without the need for additional priming.
  • Safety
    Double diaphragm pumps are designed with no seals or packing, which means there is no risk of fluid leakage. They are also equipped with an automatic shut-off feature that activates when the pump runs dry. This prevents damage to the pump and reducing the risk of accidents.
  • Easy maintenance
    Double diaphragm pumps are easy to maintain and repair. They can be disassembled quickly and easily, which allows for routine maintenance and repairs to be completed without the need for specialized tools or training.

     

Who Will Benefit from Double Diaphragm Pumps?

Double diaphragm pumps offer a versatile, durable, efficient, safe, and easy to maintain solution for moving a wide range of fluids in various industrial and commercial applications. Their ability to handle corrosive, abrasive, and viscous fluids, as well as their self-priming and automatic shut-off features, make them an attractive choice for businesses seeking a reliable and cost effective pumping solution.

Overall, double diaphragm pumps are an excellent choice for businesses seeking a reliable and efficient pumping solution that can handle a variety of fluids with minimal maintenance and downtime.

Choose The Right Milton Roy Solution For Your Application

Milton Roy has over 85 years of experience in reciprocating metering pumps and ancillary equipment that deliver reliability and accuracy in critical chemical dosing applications. We manufacture various types of chemical metering pumps to meet your application needs.