BSM Stepped EPDM Union Seal Ring

An EPDM union seal ring with a stepped cross-section designed to seat inside mating BSM sanitary union ferrules. Listed across a DN20 to DN100 series size range for hygienic pipeline joints.

Mating Interface	BSM sanitary union ferrule joint
Seal Profile	Annular union seal ring with stepped edge geometry (titled BSM Union EPDM O Ring)
Material	EPDM
Size Range	DN20~100
Ring geometry	Stepped flat-faced annular union seal ring

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Stepped Profile and BSM Union Seating

Although the series specification title refers to a BSM Union EPDM O Ring, the retained product photographs show a black annular ring with a stepped cross-section rather than a circular O-ring cord. This stepped shoulder locates the seal within the recessed groove of a matching BSM union ferrule so that tightening the union nut compresses the elastomer evenly between the male part and liner.

EPDM Elastomer Designation

Both the primary page heading and the parameter table specify EPDM as the seal material for this item, whereas the top summary block prints a generic multi-material string (Viton, EPDM, Silicone, PTFE). EPDM is selected for aqueous process streams, beverage transfer, and alkaline or hot-water cleaning routines where oil-resistant elastomers are not required.

DN20–DN100 Series Range

The product parameter table lists a nominal size range of DN20 through DN100 for the BSM union ferrule series. Because the series specification does not publish a per-size cross-sectional drawing with inside diameter, outside diameter, or step height values, exact groove dimensions should be checked against the mating BSM union hardware.

Selection and Sub-Series Checks

BSM unions can be supplied with either true circular O-ring grooves or stepped flat-face recesses depending on the union sub-series. Before ordering replacement seals, verify whether your installed BSM union requires this stepped profile or a circular O-ring, and confirm compound suitability for the process medium and temperature.