Brand: Nupro / Swagelok
Model: SS-4BK-V51-1C bellows sealed stainless steel process valve with top-mounted actuator.
Body markings: NUPRO logo with flow direction arrow on one side; SS-4BK and V51-1C engraved on the opposite side.
End connections: stainless steel Cajon 316 VCR fittings, approximately 1/4 inch size (marked CAJON PATD 316 VCR on the nuts).
Construction: stainless steel valve body and fittings with aluminum actuator housing and three-screw top cover.
Application: high-purity or vacuum/gas service where a bellows-sealed, normally closed valve with PCTFE stem tip and Swagelok VCR connections is required (per printed spec sheet shown).
See all photos for additional details and approximate size; ruler is shown for scale only.