The making of….. the stainless steel pump
The use of stainless steel plays a vital role in our production process. The stainless steel arrives in large rolls of sheet at our factory, is processed into parts and finally leaves our factory as a high grade multistage centrifugal pump. The quality of stainless steel makes the pump highly reliable and durable. Especially where high demands of drinking water and process water are concerned, the quality of the steel is crucial.
Searching for the right composition
Stainless steel is no mineral. Years of scientifical research have gone by before the right composition of this non-corroding material was found. In 1913 Harry Breary discovered that steel with over 12% of chromium is very resistant to corrosion. This was the official discovery of the first types of stainless steel.
Chromium protective component
Stainless steel is a collective noun for a Group of non-corrosive steels, that contain a minimum of 10.5% of chromium. The chromium forms an invisible coating of chromic oxide (Cr2O3) when it makes contact with oxygen. This coating protects the underlaying steel from corrosion. The coating even heals itself when it is damaged. In our production process we use two different types of stainless steel: stainless steel AISI 304 and AISI 316. The second type is more corrosion resistant than the first and is therefore used for aggressive liquids and process water.
Stainless steel at DP-Pumps factory
We process stainless steel in different types and forms. Stainless steel is brought in on large rolls of sheet and in large blocks. The blocks are tooled into large die for parts. The die are placed into 6-ton presses. The rolls of stainless steel sheet are lead through the presses where the die form and cut the parts from the steel.
At the pre-assembly department the parts are welded together by spot welding or laser welding. When this process is finished, the product of the stamping presses have become high grade parts like impellers, diffusers, pump casings etc. At another department bars of several metres long are processed into shafts and strengthening ribs. The final step in the production process is the assembly of the parts and motor, making it a pump. The pumps are either built into a unit or are sold individually.
Stainless steel in practice
When the pump leaves the factory it is extensively tested and has several important approvals (WRc, ACS) that guarantee a good drinking water quality. Thanks to the hygienic and durable characteristics of stainless steel, this material can be used perfectly in drinking water applications and a large number of other applications. The pump is used to supply water at the highest level of a building, but can just as well be used to transport salty process water in a cheese factory. In every situation the pump operates highly reliably and safely, because it is produced by people that were concerned in the design and the production of the pump.
As no other we know how a pump is built and what is needed to optimise its efficiency and make it durable. That is why we choose for high grade materials: stainless steel is one of the most important examples.