Fluid control systems within hygienic applications demand high standards in terms of cleanability which can be affected by a number of design characteristics. The base material is normally 316L stainless steel which requires an excellent surface finish in order to maximise the efficiency of the clean-in-place (CIP) process that is used to sterilise the process pipework.
Bürkert Fluid Control Systems has launched the latest incarnation of its diaphragm valve body that has been manufactured using hydroforming technology. Designed for use in hygienic process applications, the new tube valve body meets the latest standards for pharmaceutical, cosmetic as well as food and beverage industries.
The manufacturing process starts with the flange, which is laser cut and milled, and the tube, both of which are made from 316L stainless steel. The tube is placed in a mould, filled with a water-oil emulsion and subjected to around 3,000 bars of pressure to produce the required flow path to and from the diaphragm.
The flange and tube are laser welded together before the new component is annealed in order to relieve any residual stress within the material. The polishing process is automated, using an abrasive paste that is repeatedly pumped through the valve body to achieve a surface finish of less than 0.4 µm. This produces a very uniform surface which is then electro-polished to give a near mirror finish for all areas that come into contact with the process media.
This new manufacturing process enables the production of valve bodies that are up to 75% lighter than forged housings. The reduced volume of material means that the energy requirement for both heating and cooling during cleaning processes is also greatly reduced.
By reducing energy requirements and downtime for cleansing processes, the new Bürkert tube valve body has the potential to optimise process efficiency and reduce costs for a wide range of hygienic applications.