What are the advantages of diaphragm pumps compared to gear pumps

Diaphragm pumps are commonly used in a variety of transfer applications and can handle a wide range of fluids, including viscous, abrasive and shear-sensitive fluids. Double diaphragm pumps are characterised by their robustness, reliability and ease of maintenance. Thanks to the use of special materials, they can be the ideal solution for operation in hazardous or potentially explosive environments.

Advantages of diaphragm pumps

This type of operation combined with specific design configurations allows for a range of application advantages which can be summarised as follows.

Dry-running capability: diaphragm pumps do not break down when operating without fluid.

Self-priming: diaphragm pumps can be run dry and can draw in fluid even if the pump is not blocked.

Operational safety: diaphragm pumps are pneumatic and are an excellent solution for use in potentially explosive environments. The use of specific materials (e.g. carbon) makes the pump electrically conductive and therefore suitable for even the most unstable environments.

Versatility: size, materials and ease of installation make diaphragm pumps an extremely versatile solution, capable of handling a wide range of fluids from water to oil, from sewage to acids and corrosive substances.

Low shear: thanks to a special cutting speed control system, double diaphragm pumps can handle shear-sensitive fluids such as food, latex, inks and polymers.

Reduced maintenance requirements: The low propensity for component wear and damage reduces the impact of maintenance and ancillary costs.

What is a gear pump?

We now turn to gear pumps. This type of pump works by rotating gears whose task is to guide the fluid within the cavities present in the individual teeth. When the fluid chooses the path of least resistance, the latter flows through the mesh components to the drain. Depending on the type of fluid to be managed, gear pumps can have different design configurations.

Internal gear pumps are more suitable for handling viscous fluids where solid elements are present, due to the separation and re-engagement of the teeth leading to the suction and transfer of the fluid respectively. External gear pumps are more suitable for handling low viscosity fluids, trapping the fluid between the gear teeth and transferring it from the suction zone to the transfer zone.

Gear pumps are used in the chemical industry (management of resins, pigments, polymers), the paint and construction industry, the fuel industry (transport of oil and fuel) and the food industry (management of syrups, creams and molasses).

Advantages of using diaphragm pumps versus gear pumps

Below we have included a list of the advantages of using diaphragm technology compared to using gear pumps.

Dry-running capability: Double diaphragm pumps can be run dry without damaging the pump components. The same type of advantage cannot be obtained in the case of gear pumps that do not allow dry running.

Handling a wide range of fluids: Double diaphragm pumps can handle fluids with a high degree of variability in flow, viscosity and head. This variability is reduced where gear pumps have a limited ability to handle fluids with variable viscosity, thixotropy or non-Newtonian fluids.

Ability to handle abrasive fluids: The design configuration and type of materials used allow diaphragm pumps to handle abrasive fluids that are difficult to handle with gear pumps due to the high probability of component wear.

Component wear: In the case of diaphragm pumps, due to design features, the fluid does not come into contact with the main pump components. Therefore, the potential for wear is limited. In the case of gear pumps, many parts of the pump come into contact with the fluid, increasing the potential for wear and damage.

Applications: Unlike gear pumps, diaphragm pumps can easily manage frequent stops and restarts without special energy consumption.