Cartridges & Mechanical Seals

87 Sector Chemical In the chemical industry, the habitual processes require sealing elements for materials with high chemical resistance. For transfe- rring very aggressive or corrosive chemical fluids that are clean or with particles and have high viscosities, along with high tempera- tures and pressures, the mechanical seal materials and the type of assembly must be correctly defined: single, double, external or in accordance with API plans. All the above gives rise to extremely demanding requirements for the mechanical seals and for the auxiliary elements supplied with them: LTS or LQT reservoirs, or elements such as cyclones. Not only is it necessary to pay attention to the design of the mechanical seal, but also to consider the materials used to make its components: sintered silicon carbide contact surfaces (Q1), fluorinated elastomeric seals (FKM) or high resistance alloy springs (Hastelloy ® C) are an indis- pensable requirement. Applications Requirements or critical conditions of the application Type of seal recommended Chlorine and its by-products, acids, caustic products: → Bellows seal (PTFE). Corrosive fluids Detergents: → Multispring seal (double). Viscous products Fertilisers: Chemically aggressive fluids → Double cartridge seal, reservoirs and wave spring seal. Sticky products Varnishes and paints: → Double cartridge seal, reservoirs, multispring seal, (external arrangement) and wave spring seal. Paste-like products Pulp and paper: Furthermore, the applications require sealing systems that guarantee safety, preventing the leakage of corrosive or flammable products that could enter the atmosphere. In this sector the ATEX certification is often required, to ensure equipment’s safety when working in explosive environments. → Bellows seal (PTFE).