Sanitary grade centrifugal pumps usually do not produce emissions or residues during normal use. This type of pump is mainly designed to handle hygienic liquids such as food, medicine, cosmetics, etc. Its structure and materials are specially designed and selected to ensure that no residues or emissions accumulate inside the pump.

The following are the measures commonly taken by sanitary grade centrifugal pumps to avoid the generation of emissions or residues:

1. Material selection: Sanitary grade centrifugal pumps are usually made of 316L stainless steel or other materials that meet hygiene standards. These materials have good corrosion resistance and cleanliness, and can effectively prevent the accumulation of residues.

2. Surface treatment: The internal and external surfaces of the pump are usually treated with polishing or electron microscopy to reduce surface roughness and reduce the possibility of residue adhesion.

3. Sealing design: The sealing design of sanitary grade centrifugal pumps is relatively strict, ensuring that the liquid inside the pump will not leak or seep out, and avoiding the impact of emissions on the environment.

4. Cleaning: Before and after using sanitary grade centrifugal pumps, strict cleaning and operation are usually required to ensure that there is no residue inside the pump and it meets hygiene standards.

5. Emission treatment: If a sanitary grade centrifugal pump produces a small amount of emissions or residues during use, corresponding treatment measures should be taken, such as collection, treatment, and disposal, to ensure no impact on the environment and products.

Overall, the design and operation of sanitary grade centrifugal pumps are aimed at avoiding the generation of emissions or residues, but in practical use, strict adherence to clean and hygienic operating procedures and standards is still necessary to ensure product quality and hygiene in the production environment.