How Diaphragm Pumps Are Made

Pumps are used for various processes in nearly every branch of the industry, including painting, cosmetic, pharmaceutical, printing, chemical, petrochemical, and food sectors. They are used for wastewater treatment, dosing of acids, or transport of reagents, suspensions, and various types of liquids, and for many other applications.
Pumps can be divided into centrifugal, in which an impeller causes a flow of the medium, and positive displacement pumps, changing the volume of the space containing the liquid. The positive displacement pumps include universal diaphragm pumps driven by compressed air or equipped with electrical drives. Pumps can either be stand-alone devices or become a part of a larger system.
Today we will see how diaphragm pumps are manufactured. For this purpose, we visited Tapflo Production facility in Tczew, northern Poland.
The company Tapflo was established in 1980 in Kungälv, near Göteborg, Sweden. Currently, the production and distribution centre of the Tapflo Group is located in Poland. We have our own distribution companies in 30 countries all over the world.
Let’s take a look at the operation (working principle) of a diaphragm pump. Two diaphragms are connected by a shaft and pushed firstly in one direction, and then the other by means of alternate supply of compressed air to chambers located behind these diaphragms. The air is automatically re-directed by an air distributor. The pumped liquid is located in the chambers on the other side of the diaphragms. When the volume of one of these chambers is increased, the suction stroke is performed. At the same time, the volume of the chamber on the opposite side of the pump is automatically reduced and a discharge stroke is performed. Valve balls open and close controlling the flow. The liquid is drawn into the chambers and then discharged into the system.
Designers’ work is crucial for the pump to operate correctly. The production process starts in their department. All pump designs are developed here.
Using simulations, the manufacturing processes and pump operation can be verified already at the design stage. Thanks to virtual prototyping, the number of physical prototypes and their tests is reduced to a minimum, so the production process can start much earlier.
A process engineer confirms that the designed models are optimized for production. He also prepares codes for CNC machines.
Based on a production order, the warehouse operators prepare materials that will be used for production, usually polypropylene or polyethylene and steel or brass rods.
Then the raw materials are cut to appropriate dimensions with a saw, They are later processed on CNC machines. A center block, in which an air distributor will be installed, is produced on a 5 axis CNC Multi-tasking machines.
A pump housing is produced on a 4 axis turning centre, by machining a polyethylene plate. Here, valve balls are machined. Some pumps are equipped with a dampener, that reduces pulsations caused by the pump operation.
Sharp edges of details are deburred after machining operations.
Then the quality control department performs its measurements, verifying components height and width, duct diameters, and surface roughness. The utilized measurement equipment enables measurements to the nearest micron. The quality department is also responsible for the incoming inspection, verifying quality of materials used for production.
Basing on a production order, the components are delivered to the ready parts warehouse, where workers select parts for the assembly department. All parts used to assemble a pump are prepared.
At the assembly department, we start with assembly of the pump housings, installing pump feet, valve balls, and sleeves that guide the balls. The air distributor is prepared at the same time, and then installed in the center block. The diaphragms are also assembled on this component. Finally, the center block is being assembled together with the both sides of pump housing.
After the nameplate is engraved, it is time for the final tests. The pump is connected to a test bench and its operation is verified. Every pump manufactured at the plant undergoes such tests. Tapflo devices offer thousands of configurations.
The newly made pumps are packed into carton boxes and then into secondary packaging. Every month, the plant in Poland manufactures about 4000 pumps and devices, delivered to customers all over the world.