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8621-3 — SEAT,VALVE

✓ Government record, cited
Nathan · GATE VALVE
PRODUCT OVERVIEW

8621-3: SEAT,VALVE.

The SEAT,VALVE is a Nathan industrial component. Key specifications include material: STEEL OVERALL, special_features: U/O WILLIAMS GATE VALVE FIGURE 15F-1MP, style_designator: PLAIN THREADED, seating_surface_shape: FLAT, end_item_identification: WHIDBEY ISLAND CLASS LHD. This part is cataloged in the U.S.

Government catalog under NSN 4820-01-436-0671, 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
8621-3
NSN: 4820-01-436-0671
FSC: 4820 — Valves, Nonpowered
CAGE: 79342 — WILLIAM E WILLIAMS VALVE CORP (USA)
SPECIFICATIONS
materialSTEEL OVERALL
special_featuresU/O WILLIAMS GATE VALVE FIGURE 15F-1MP
style_designatorPLAIN THREADED
seating_surface_shapeFLAT
end_item_identificationWHIDBEY ISLAND CLASS LHD
NSN4820-01-436-0671
COMPONENT DIAGRAM
GATE VALVE — FULL OPEN OR FULL CLOSE ONLY Rising STEM BONNET FLOW → → FLOW SEATS — — SIZE: — · — · — PN: 8621-3 · Nathan ⚠ VERIFY BEFORE ORDERING Gate valves = FULL OPEN or FULL CLOSE only — never throttle. Partial opening causes seat erosion and vibration. ✓ BROKER TIP Rising stem shows valve position visually — easier maintenance. Non-rising stem saves headroom. PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
STYLE DESIGNATOR: PLAIN THREADED
•
MATERIAL: STEEL OVERALL
•
SEATING SURFACE SHAPE: FLAT
TECHNICAL CHARACTERISTICS
STYLE DESIGNATORPLAIN THREADED
SPECIAL FEATURESU/O WILLIAMS GATE VALVE FIGURE 15F-1MP
END ITEM IDENTIFICATIONWHIDBEY ISLAND CLASS LHD
MATERIALSTEEL OVERALL
SEATING SURFACE SHAPEFLAT
SUBSTITUTES & CROSS-REFERENCES 1
8621Reference document
Same NSN cross-reference
Reference document — Drawing number reference only
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 8621-3?
8621-3 is a SEAT,VALVE manufactured by Nathan.
What parts can replace 8621-3?
There is 1 known substitute for 8621-3: 8621. Substitute compatibility should be verified for your specific system.
What is the NSN for 8621-3?
8621-3 is cataloged in the U.S. Government catalog under NSN 4820-01-436-0671. 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.