Substances used in the food and chemical industries are in many cases the same, whether they are natural sources or synthetic production. Regardless of their type and occurrence (whether in process media, raw materials of products or finished products). The materials used for seals and engineering components used in production equipment contacting with various chemicals must meet specific purity requirements and have corrosion resistance to use chemicals under given process conditions. Therefore, purity and stability are the basic premise of materials in chemical processing industry and food industry. The challenge is to choose the right sealing material for the application. Whenever materials are used in the production of food and drink, it is usually necessary to ensure the neutrality of certain aspects, such as taste and smell. During the production process, the sealant shall not release any components, and even if it is harmless to human health, it will not affect the quality of the final product in any sense or other way.
Mechanical seal can be used for dynamic and static sealing of the pumped fluid. The product is sealed with atmosphere by static sealing along the pump shaft and shell, and the mating surface of rotation and fixed surface is sealed dynamically. Due to corrosion, product contamination and chemical resistance, material selection is critical for mechanical seals and wet parts of pumps. This is important for pumps in food and beverage applications because it prevents toxic particles from entering the pumped fluid. Nickel is suitable for use where caustic and other alkalies are required, and can also be used to protect the purity of products when handling food and synthetic fibers. Nitrile, fluorocarbon, ethylene propylene and polytetrafluoroethylene (PTFE) materials are suitable for use in food and beverage services. On the other hand, due to the content of tin and lead, some grades of bronze cannot be used for food service.