Product specifications

Attribute	Specification
Manufacturer	Swagelok.
Part number	SS‑4BA‑K1.
Kit type	Bellows replacement / maintenance kit for BK series bellows‑sealed valves with 1‑series pneumatic actuators.
Contents	Welded subassembly (stem, bellows, weld ring), piston and stem O‑rings, lock nut, washer, pins, and instructions.
Materials	Stainless steel kit components for stainless steel and brass BK valves (ordering number denotes SS kit).
Compatible valve series	4BK, 6BK, 8BK and BK series valves with 1‑series pneumatic actuators (verify valve series on your valve nameplate).
Intended use	Field maintenance and repair to restore bellows seal integrity and stem assembly function.
Condition notes	Manufacturer‑controlled spare; some distributors require end‑user information for warranty/traceability.
Typical packaging	Individual kit with instructions and replacement subassembly; sold per kit.

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Key details and seller notes

• Fit confirmation — Buyers should confirm their valve series and actuator type (1‑series pneumatic) before purchase; the kit is specific to BK family valves.
• What the kit replaces — The welded stem/bellows subassembly is the pressure‑boundary replacement; O‑rings and hardware restore piston and stem sealing.