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B27778 — SEAL ASSEMBLY,SHAFT,SPRING LOADE

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

B27778: SEAL ASSEMBLY,SHAFT,SPRING LOADE.

SEAL ASSEMBLY,SHAFT,SPRING LOADE. Key specifications include material: COTTON OR CORK AND RUBBER CHLOROPRENE CLASS CR OVERALL, hole_diameter: 0.250 INCHES NOMINAL LOCATION NOT OTHERWISE SPECIFIED IN, outside_diameter: 7.688 INCHES NOMINAL IN, style_designator: CIRCULAR, aperture_diameter: 6.000 INCHES NOMINAL IN, bolt_circle_diameter: 7.125 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5330-00-591-4693, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
B27778
NSN: 5330-00-591-4693
NIINs: 005914693, 012043283
FSC: 5330 — Packing and Gasket Materials
CAGE: 01379 — EMERSON PROCESS MANAGEMENT VALVE AUTOMATION, INC. (USA)
SPECIFICATIONS
materialCOTTON OR CORK AND RUBBER CHLOROPRENE CLASS CR OVERALL
hole_diameter0.250 INCHES NOMINAL LOCATION NOT OTHERWISE SPECIFIED IN
outside_diameter7.688 INCHES NOMINAL IN
style_designatorCIRCULAR
aperture_diameter6.000 INCHES NOMINAL IN
bolt_hole_quantity8
bolt_circle_diameter7.125 INCHES NOMINAL IN
cross-sectional_thickness0.062 INCHES NOMINAL IN
cross-sectional_shape_styleSOLID SINGLE OR COMPOSITION
material_document_and_classification780,FSCM 13440 MFR REF 1ST MATERIAL RESPONSE OR 792,FSCM 13440 MFR REF 2ND MATERIAL RESPONSE OVERALL
NSN5330-00-591-4693
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: B27778 MFR: OEM ⚠ VERIFY BEFORE ORDERING Wrong material = failure. Viton for oil/fuel, EPDM for water/steam, Buna-N for general purpose, Silicone for food-grade. Chemical incompatibility causes swelling, brittleness, or rapid degradation ✓ BROKER TIP Durometer (hardness) affects sealing pressure tolerance. Higher Shore A = harder = higher pressure. Standard durometer is 70A — verify if application requires different hardness PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
CROSS-SECTIONAL THICKNESS: 0.062 INCHES NOMINAL IN
•
STYLE DESIGNATOR: CIRCULAR
•
MATERIAL DOCUMENT AND CLASSIFICATION: 780,FSCM 13440 MFR REF 1ST MATERIAL RESPONSE OR 792,FSCM 13440 MFR REF 2ND MATERIAL RESPONSE OVERALL
•
CROSS-SECTIONAL SHAPE STYLE: SOLID SINGLE OR COMPOSITION
•
OUTSIDE DIAMETER: 7.688 INCHES NOMINAL IN
•
APERTURE DIAMETER: 6.000 INCHES NOMINAL IN
•
BOLT HOLE QUANTITY: 8
•
BOLT CIRCLE DIAMETER: 7.125 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
CROSS-SECTIONAL THICKNESS0.062 INCHES NOMINAL IN
STYLE DESIGNATORCIRCULAR
MATERIAL DOCUMENT AND CLASSIFICATION780,FSCM 13440 MFR REF 1ST MATERIAL RESPONSE OR 792,FSCM 13440 MFR REF 2ND MATERIAL RESPONSE OVERALL
CROSS-SECTIONAL SHAPE STYLESOLID SINGLE OR COMPOSITION
OUTSIDE DIAMETER7.688 INCHES NOMINAL IN
APERTURE DIAMETER6.000 INCHES NOMINAL IN
BOLT HOLE QUANTITY8
BOLT CIRCLE DIAMETER7.125 INCHES NOMINAL IN
MATERIALCOTTON OR CORK AND RUBBER CHLOROPRENE CLASS CR OVERALL
HOLE DIAMETER0.250 INCHES NOMINAL LOCATION NOT OTHERWISE SPECIFIED IN
SUBSTITUTES & CROSS-REFERENCES 1
B027768Reference document
Same NSN cross-reference
Reference document — Design control — primary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is B27778?
B27778 is a SEAL ASSEMBLY,SHAFT,SPRING LOADE.
What parts can replace B27778?
There is 1 known substitute for B27778: B027768. Substitute compatibility should be verified for your specific system.
What is the NSN for B27778?
B27778 is cataloged in the U.S. Government catalog under NSN 5330-00-591-4693. This indicates validated use in U.S. government and defense supply chains.
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PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.