Gasketed

Gasketed describes a seal arrangement that uses a gasket to prevent leakage between mating surfaces. In mechanical engineering, a gasketed joint or closure relies on compressing a gasket material to fill irregularities and establish a pressure-tight seal under operating loads, temperatures, and vibrations.

Gasket materials vary widely, including elastomers (such as NBR, EPDM, FKM/Viton, silicone), PTFE, graphite, and compressed fiber compounds. Metal gaskets are used for high-temperature or high-pressure services, sometimes in combination with soft seals. Material choice depends on chemical compatibility, temperature and pressure, surface finish, and the presence of aggressive fluids.

Common applications include flanged piping connections, valve bonnets, pump housings, pressure vessels, heat exchangers, and manways. In food, pharmaceutical, or clean environments, sanitary gaskets and hygienic gaskets are designed to minimize crevices and allow easy cleaning.

Design considerations include selecting the correct gasket type and thickness, ensuring adequate seating stress, and verifying flange surface finish and bolt preload. Gasket performance can be affected by bolt creep, gasket relaxation, and thermal cycling, so bolt-up procedures and re-torquing may be required.

Advantages of gasketed joints include ease of disassembly for maintenance, ability to seal irregular or dissimilar surfaces, and adaptability across temperature ranges. Limitations include potential leakage if undersized or improperly compressed, the need for periodic replacement, and, in metal-to-metal seals, risks of galling.

Standards and guidelines for gasketed joints are issued by organizations such as ASME and ISO, covering gasket selection, gasket seating stresses, bolt patterns, and testing procedures.