Diaphragm Metering Pump for Special Low Flows and Pressures

What is a Metering Pump?

A metering pump is used to add small but accurate volumes (doses) of a liquid or powder concentrate to other fluid streams such as water drinking tanks or vessels. Metering pumps are also called dosing pumps and proportioning pumps. A metering pump must be able to deliver liquid with an accuracy of greater than 3% across a wide range of discharge pressures.

What is a Diaphragm Metering Pump?

A diaphragm metering pump is a positive displacement pump designed to operate as a proportional dosing pump. It uses a flexible diaphragm in place of a piston to change the volume of the pump’s chamber to increase and decrease pressure on the fluid inside.

How does a Diaphragm Metering Pump Work?

A diaphragm metering pump works just like a piston pump. The water drives the diaphragm up and down. The plunger is fixed to the diaphragm, which pumps the product into the main water flow. At the output, the volume of a dosed product is proportional to the driving water volume.

Where and Why are Diaphragm Metering Pump Used?

Metering pumps are required in many industries, including water treatment, chemical processing, and animal health applications. The concentrate can be anything from fertilizers, water treatment additives, and medicines. The main application for a diaphragm metering pump is the treatment of drinking water in the avian sector. It is also used for accurate dosing of, for example, fertilizer and medicine in small farming businesses. A diaphragm moves up and down without friction and without internal leakage. This allows the pump to start at a very low flow and pressure, even if using a tap, borehole or surface water.

Diaphragm Dosing Pump Working Principle

Installed directly to the water supply line, the diaphragm metering pump operates by using water pressure as its power source. The water activates the pump, which takes up the required percentage of dosed concentrate.

Inside the diaphragm metering pump , the concentrate is mixed with the water. The water pressure forces the solution downstream. The dose of concentrate is directly proportional to the volume of water entering the diaphragm metering pump. This is regardless of variations in flow or pressure which may occur in the main line.

Read more about the technology

diaphragm metering pump operating principle
Diaphragm Metering Pump operating principle

Discover the operating principle of our Diaphragm Metering Pump in this video.

Diaphragm Metering Pump Installation Hints

The Diaphragm Metering Pump can be connected to the main water line directly or on a by-pass. To prolong the working life of the pump, it is advisable to install a filter, (for example, 300 mesh - 60 microns depending on your water quality) upstream. This is imperative if the water contains impurities or particles, especially if the water comes from a well.

A filter is recommended and required for the warranty to be valid.

diaphragm metering pump installation hint


Do not put the suction tube strainer on the bottom of the stock solution container. The strainer must be suspended at least 10 cm [4”] above the bottom of the tank to avoid sucking up the insoluble particles that may damage the injection assembly. Do not put the strainer on the ground.

Installation for Operation Using Gravity

To power and operate the pump using the pressure that gravity imposes on fluids, follow these recommendations.

According to the required installation type and water flow, provide at least 1.5 meters for the hydraulic head. Take into account pressure loss from the components of the installation such as filter, hose lengths, check-valves, etc.

installation diaphragm metering pump

Diaphragm Metering Pump Maintenance

When using soluble products to be dissolved, it is recommended to regularly disassemble the entire dosing part.

If it is difficult to reassemble, rinse all parts of the dosing part carefully with water and refit them after greasing the seal with a silicone lubricant.

Before putting the diaphragm metering pump into service after a period of non-use, remove the piston and seal assembly and soak it in warm water < 40° C [104° F] for a few minutes. This will dissolve any deposits.

This video tutorial is intended to help you perform maintenance on the DIA4AL Diaphragm Metering Pump.

The difficulty level of this tutorial is about : 3/5 (normal).

A very simple and quick maintenance to increase the resistance of your diaphragm metering pump.
If you have any questions, please contact your distributor.

For more information, see all our videos on our dosatron.tv dedicated website.


Dipahrag metering pump exploded view
Cross-section view of the Diaphragm Metering Pump

Diaphragm Metering Pump Technology Explained

With its flow range of 4.5 to 2500 l/h and a dosing rate from 1 to 4%, the diaphragm metering pump (DIA4AL) is the ideal solution for animal health applications.

This technology is also ideal for very low water pressure conditions when using header tank water systems. Thanks to its 4% high dosing capability you will ensure good solubility of most oral powders into your stock solution tank.

Based on diaphragm technology, the DIA4AL motor has an exceptional life span even with mineral loaded water and heavy load operation. The DIA4AL has the lowest motor maintenance cost on the market.

The external injection of available additives can also protect the motor from potential corrosion effects.

An Animal Health Dedicated Product

Our Animal Health market expert Angèle Suzanne introduces our diaphragm metering pump, the DIA4AL for low flows and low pressures.

For all kinds of livestock (poultry, pork, cattle, rabbits, etc.), our Diaphragm Metering Pump enables you to dose treatments and to vaccinate animals.