Diaphragm pumps Manufacturers online

Diaphragm pumps are special positive displacement pumps that use a flexible diaphragm system to pump liquids or gases.

They are widely used in industries such as chemicals, pharmaceuticals, food, water treatment and waste water management, as they are also suitable for aggressive or sensitive media.

Below you will find how they work, the different types of diaphragm pumps, their areas of application and their advantages:

How diaphragm pumps work:

Diaphragm pumps consist of a housing with a flexible diaphragm that moves mechanically to create a vacuum (suction) and positive pressure (delivery). The pumping process works in several steps:

The diaphragm is moved back and forth by mechanical or pneumatic force. In pneumatic diaphragm pumps, this is done by air pressure, while in mechanical pumps an eccentrically driven piston generates the movement. When the diaphragm retracts, a vacuum is created in the pump housing. This draws the medium through the suction valve into the pump chamber. When the diaphragm moves back to the starting position, the pressure in the chamber increases, forcing the medium out through the outlet valve. Suction and discharge valves (usually non-return valves) ensure that the medium can only flow in one direction. The diaphragm movement and the valves thus enable a continuous flow.

Types of diaphragm pumps:

There are two main types of diaphragm pumps:

• Pneumatic diaphragm pumps: These are operated with compressed air and are suitable for aggressive or viscous media. They are easy to control and do not require any electrical components, making them safe for potentially explosive environments.
• Mechanical diaphragm pumps: These are mechanically driven by an electric motor or piston and are suitable for more precise flow rates as the drive is easily adjustable.

Areas of application for diaphragm pumps:

Diaphragm pumps are used in many industries due to their versatility:

1. Chemical industry:
Due to their chemical resistance, diaphragm pumps can pump aggressive, abrasive or sensitive media, such as acids, alkalis and solvents.

2. Pharmaceutical and food industry:
Here, diaphragm pumps are often used for sterile and hygienic applications, as they are easy to clean and operate without lubricants.

3. Water and waste water treatment:
They are suitable for pumping wastewater and sewage as they also tolerate particles and solids in the medium.

4. Agriculture and horticulture:
Diaphragm pumps are often used for fertilizers and pesticides as they have robust and chemically resistant materials.

5. Aerospace and medicine:
Small, precise diaphragm pumps are used for accurate metering of gases and liquids, such as in respirators and medical devices.

Advantages of diaphragm pumps:

• Diaphragm pumps can run dry without being damaged, which makes them suitable for irregular pumping processes.
• They do not require an additional device to draw in the medium and can therefore be used flexibly.
• The diaphragm can be made of resistant materials (e.g. PTFE), which makes them suitable for aggressive media.
• Diaphragm pumps can also pump liquids containing solids without this impairing their function.
• The delivery pressure can be easily adjusted, making diaphragm pumps suitable for applications with changing pressure requirements.

Diaphragm pumps are extremely versatile and robust pumps that are suitable for pumping liquids and gases, especially when aggressive or viscous media need to be pumped. The selection of the right model depends on the requirements of the application, such as flow rate, pressure, chemical resistance and controllability.

Here you will find an overview of the most important criteria to look out for when purchasing diaphragm pumps:

When purchasing diaphragm pumps, there are several important factors to consider to ensure that the pump meets the specific requirements and operates reliably.

• The pump should be able to deliver the desired flow rate, which is usually specified in liters per minute (l/min) or per hour (l/h).
• The delivery pressure is also crucial and should be matched to the application, especially when liquids are pumped over long distances or against high back pressure.
• The diaphragm must be compatible with the pumped medium. Resistant materials such as PTFE (Teflon) are suitable for aggressive chemicals, while NBR (nitrile rubber) is used for oil and grease. EPDM is suitable for water-based media.
• The housing material should also be matched to the medium. Stainless steel is suitable for corrosive media, plastic for acids, and cast iron for less aggressive liquids.
• Pneumatic diaphragm pumps are ideal for potentially explosive environments and applications where electrical components are to be avoided.
• Electric diaphragm pumps often offer more precise control and are well suited to applications where accurate flow rates are required.
• The pump should be self-priming, especially when pumping from a tank below the pump level.
• A dry-run safe pump can also be operated without medium without being damaged. This is important in applications with irregular media flow.
• The pump must be resistant to the medium, especially in the case of aggressive or abrasive liquids.
• If the medium contains solid particles, the pump should be designed so that it can pump a certain particle size without clogging.
• The pump should be designed for the maximum temperature of the medium.
• The ambient temperature also plays a role, especially in industrial or extreme environments.
• If the flow rate needs to be precisely controlled, for example in dosing applications, the pump should be easily adjustable.
• Some diaphragm pumps offer digital interfaces (e.g. for PLCs), which enables more precise control and integration into automated processes.
• Pay attention to the energy requirements of the drive, especially with pneumatic pumps, as compressed air can be cost-intensive.
• An efficient pump saves energy costs and reduces wear. Efficiency is a particularly important factor in continuous applications.
• Choose a pump that is easy to maintain, with easily accessible components and a modular design.
• Make sure that spare parts such as diaphragms, valves and seals are readily available to minimize downtime.
• The price should be in relation to the planned service life and load of the pump.
• Take into account maintenance and energy costs, which may be lower in the long run with a high-quality model than with cheaper alternatives.

A careful analysis of the pumping requirements, media compatibility, operating conditions and maintenance requirements is crucial in order to select a suitable diaphragm pump. With the right diaphragm pump, processes can be designed to be stable and efficient, and the investment pays off in the long term through greater reliability and lower operating costs.

Diaphragm pumps can be purchased from various suppliers. Comprehensive information about manufacturers and suppliers of Diaphragm pumps from all over the world can be found on Exportpages.