Hygienic pumps are generally used in the food, pharmaceutical and cosmetics sectors, where human health is most critical. Equipment used in these sectors must meet certain standards in order to protect human health. Some of these standards are 3-A, the European Hygienic Engineering and Design Group (EHEDG), and the FDA (Food and Drug Administration).
The most important point in hygienic pumps is surface smoothness. Older literature accepted a surface roughness value of 3.2 μm as the starting point for the hygienic standard, whereas today 0.8 μm, or even 0.4 μm is a far more suitable and widely accepted value.
The first surface shown at the side is sand-mould casting, the second is precision casting, and the last is the surface roughness of a drawn steel material. As can be seen, roughness is quite high with the first two casting methods. For this reason, drawn steel material is used in the manufacture of hygienic pumps. These surface irregularities in the material are too small to cause a significant technical problem in standard processes. However, they represent fairly large areas for bacteria to settle and multiply.
Another feature of hygienic pumps and equipment is that they can be cleaned quickly and drained easily. Cleaning is generally carried out in one of two ways: "Clean-in-Place (CIP)" or "Clean-Out-of-Place (COP)". COP is a laborious and time-consuming method and is not preferred unless necessary; its basic principle involves dismantling all or part of the equipment, cleaning it elsewhere, and reassembling it. CIP, on the other hand, requires an additional system to be set up at the outset of production planning, but once the system is installed, cleaning takes place quickly and easily. In CIP, cleaning chemicals are passed through the same lines and equipment as the food product, by means of hygienic pumps, with CIP pumps generally being used for this. Rinsing is then carried out along the same path, completing the cleaning process.
GEA Hilge HYGIA
