The HYG55 is the hygienic N4X replacement gasket for the smallest enclosures in the HYPB Series of hygienic Type 4X stainless steel pushbutton enclosures. It is listed as the replacement gasket for the single-hole HYMPB1SSR (22mm hole) and HYPB1SSR (30mm hole) enclosures, which measure 4.98 in (126 mm) high by 4.98 in (126 mm) wide by 4.00 in (102 mm) deep. Maintenance teams in hose-down facilities can keep a spare on hand so a worn or contaminated seal can be swapped without replacing the enclosure.

In the HYPB Series the silicone gasket mounts around the entire door edge rather than inside a channel, which makes the seal easy to reach during washdown. The series documentation notes that the gasket can be easily removed and re-installed for cleaning or replacement, and that additional silicone gaskets can be ordered separately, which is exactly the role the HYG55 fills. The series overview describes the gasket as a removable blue silicone gasket that is easier to spot contaminants on.

The HYG55 is listed at 5 in x 5 in x 1 in (127 mm x 127 mm x 25 mm) with a shipping weight of 1 lb (0.45 kg). It carries UL File # E517628/E65324 and is REACH and RoHS compliant.

The enclosures it fits are formed 304 stainless steel with sides sloped 3° on all four sides, continuously welded seams ground smooth and a smooth #4 dairy finish, and are rated UL 508A and CSA Type 3R, 12, 4, 4X and IEC 60529 IP69/IP69K. Keeping the door-edge seal in good condition is part of maintaining that washdown protection. Order HYG55 for the 4.98 in square single-pushbutton size only; the larger HYPB enclosures use their own gasket part numbers.