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A-21404 — SEAT,VALVE

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

A-21404: SEAT,VALVE.

The SEAT,VALVE is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, flange_diameter: 0.682 INCHES NOMINAL IN, style_designator: PLAIN FLANGED, surface_treatment: CADMIUM OVERALL, under_flange_height: 0.297 INCHES NOMINAL IN, body_inside_diameter: 0.336 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5330-00-480-6178, 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
A-21404
NSN: 5330-00-480-6178
NIINs: 004806178, 007164339
FSC: 5330 — Packing and Gasket Materials
CAGE: 1XHG5 — MACROTECH POLYSEAL INC (USA)
SPECIFICATIONS
materialSTEEL OVERALL
flange_diameter0.682 INCHES NOMINAL IN
style_designatorPLAIN FLANGED
surface_treatmentCADMIUM OVERALL
under_flange_height0.297 INCHES NOMINAL IN
body_inside_diameter0.336 INCHES NOMINAL IN
body_outside_diameter0.682 INCHES NOMINAL IN
seating_surface_shapeFLAT
seal_accommodation_typeGROOVED
flange_seat_to_disk_end_height0.073 INCHES NOMINAL IN
NSN5330-00-480-6178
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: A-21404 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 HEIGHT: 0.309 INCHES MINIMUM AND 0.319 INCHES MAXIMUM IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: 16947,22105,FSCM 07060 MFR REF SINGLE MATERIAL RESPONSE OVERALL
•
PERIPHERAL DIAMETER: 1.950 INCHES NOMINAL IN
•
CENTER HOLE DIAMETER: 1.740 INCHES MINIMUM AND 1.750 INCHES MAXIMUM IN
•
MATERIAL: PLASTIC OVERALL
TECHNICAL CHARACTERISTICS
CROSS-SECTIONAL HEIGHT0.309 INCHES MINIMUM AND 0.319 INCHES MAXIMUM IN
MATERIAL DOCUMENT AND CLASSIFICATION16947,22105,FSCM 07060 MFR REF SINGLE MATERIAL RESPONSE OVERALL
PERIPHERAL DIAMETER1.950 INCHES NOMINAL IN
CENTER HOLE DIAMETER1.740 INCHES MINIMUM AND 1.750 INCHES MAXIMUM IN
MATERIALPLASTIC OVERALL
SUBSTITUTES & CROSS-REFERENCES 1
TF404-327NSame NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
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 A-21404?
A-21404 is a SEAT,VALVE.
What parts can replace A-21404?
There is 1 known substitute for A-21404: TF404-327N. Substitute compatibility should be verified for your specific system.
What is the NSN for A-21404?
A-21404 is cataloged in the U.S. Government catalog under NSN 5330-00-480-6178. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
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.