Basic structure and materials of sanitary pump
Basic structure and materials of sanitary pump
1. Structure: the pump has CIP (in-situ cleaning) or SIP (in-situ sterilization) function, smooth transition in the pump cavity, so that the contact surface between the pump and the material can be effectively cleaned; parts in contact with the material are easy to remove and install, and easy to clean. The shaft seal of the pump adopts the packing less seal, such as mechanical seal. For centrifugal pumps, impellers shall be designed to be open.
2. Materials: 300 series stainless steel, such as 304, 316L, etc. shall be used as the contact surface with materials; plastic or rubber, such as EPDM, silicone rubber, polytetrafluoroethylene, etc. in contact with materials, shall be relatively stable in the working environment, can withstand normal cleaning, insoluble, non-toxic and non absorbent.
3. Processing requirements: after polishing and other treatment, the surface roughness Ra of stainless steel in contact with materials shall not be greater than 0.8 μ m, and there shall be no defects such as pores, wrinkles and cracks. The appearance of the pump shall be smooth and bright without obvious scars. The surface weld shall be polished and flat without obvious depression or bulge.
In the selection of sanitary pump, the requirements of medium characteristics shall be met. For the pump conveying inflammable, explosive, toxic or valuable medium, the shaft seal shall be reliable or the leakage free pump shall be used, such as magnetic drive pump (without shaft seal, the isolated magnetic indirect drive shall be used). For the pump conveying corrosive medium, the convection parts shall be made of corrosion-resistant materials, such as fluoroplastic corrosion-resistant pump, and for the pump conveying medium containing solid particles For quality pumps, wear-resistant materials shall be used for convection parts, and clean liquid shall be used for shaft seal flushing if necessary.