PartsTable TECHNICAL DATA SHEET

NSN 4820-01-201-6599Government record, cited

Seat, Valve4820-01-201-6599

NSN 4820-01-201-6599 · NIIN 012016599

FSC 4820 — Valves, Nonpowered · FSG 48 — Valves

Government record, cited

Also searched as 4820-01-201-6599 · 4820012016599 · NIIN 012016599 · 01-201-6599 · FSC 4820 Valves, Nonpowered · 77774-35X3 PIECE 11 · 77774-35X3 · SS(N)637-300-2144167

Nearby stock numbers ← 4820-01-201-6322 · 4820-01-201-6657 →

4820-01-201-6599 — Valves, Nonpowered

Features

Seat,valve — FSC 4820
Flange Seat to Disk End Height: 0.500 INCHES NOMINAL IN
Flange Diameter: 14.500 INCHES NOMINAL IN
Body Outside Diameter: 12.125 INCHES NOMINAL IN
Style Designator: PLAIN FLANGED
Body Inside Diameter: 10.000 INCHES NOMINAL IN
Under Flange Height: 1.953 INCHES NOMINAL IN
Material: STEEL CORROSION RESISTING SEAT

Identification

NSN: 4820-01-201-6599
NIIN: 012016599
FSC: 4820 — Valves, Nonpowered
FSG: 48 — Valves

General Description

The Seat,valve, cataloged under National Stock Number 4820-01-201-6599, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 8 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.

Technical Specifications

Parameter	Value
NSN	4820-01-201-6599
Item Name	Seat,valve
FSC / FSG	4820 / 48 — Valves, Nonpowered
Status	ACTIVE
Flange Seat to Disk End Height	0.500 INCHES NOMINAL IN
Flange Diameter	14.500 INCHES NOMINAL IN
Body Outside Diameter	12.125 INCHES NOMINAL IN
Style Designator	PLAIN FLANGED
Body Inside Diameter	10.000 INCHES NOMINAL IN
Under Flange Height	1.953 INCHES NOMINAL IN
Material	STEEL CORROSION RESISTING SEAT
Seating Surface Shape	FLAT

Lifecycle & Compliance

Acquisition Status	ACTIVE
DEMIL Code	DEMIL A — No Demilitarization Required
Hazard	No hazard code in the DLA record (HMIC N)
Criticality Code	X

⇄ Related Items 5

Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.

4820-01-201-673077774-35X3 PIECE 23 POSSIBLE MATCH

RETAINER,BALL PIVOT,VALVE

Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat

4820-01-201-673177774-35X3 PIECE 5 POSSIBLE MATCH

RETAINER,PIVOT,VALVE

Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat

4820-01-202-034677774-35X3 PIECE 13 POSSIBLE MATCH

RING,SPRAY

Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat

3040-01-202-058677774-35X3 PIECE 1 POSSIBLE MATCH

LEVER,REMOTE CONTROL

Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat

3120-01-209-813477774-35X3 PIECE 9 POSSIBLE MATCH

BEARING,SLEEVE

Possible match (shared part number)Unimasco Inc

Cross-Reference Index

No manufacturer part numbers on file in the U.S. Government catalog.

Reference documents

Reference	Meaning
77774-35X3 PIECE 11	3/2 Design control — primary reference U.S. Government activity
77774-35X3	D/9 Drawing number reference only U.S. Government activity
SS(N)637-300-2144167	D/9 Drawing number reference only U.S. Government activity

Related Parts

4820-01-201-6730POSSIBLE MATCH

RETAINER,BALL PIVOT,VALVE

77774-35X3 PIECE 23

4820-01-201-6731POSSIBLE MATCH

RETAINER,PIVOT,VALVE

77774-35X3 PIECE 5

4820-01-202-0346POSSIBLE MATCH

RING,SPRAY

77774-35X3 PIECE 13

3040-01-202-0586POSSIBLE MATCH

LEVER,REMOTE CONTROL

77774-35X3 PIECE 1

3120-01-209-8134POSSIBLE MATCH

BEARING,SLEEVE

77774-35X3 PIECE 9

Frequently Asked Questions

What is NSN 4820-01-201-6599?

NSN 4820-01-201-6599 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.

What NSN replaces 4820-01-201-6599?

5 possible matches (shared part number, not a government interchangeability claim): 4820-01-201-6730, 4820-01-201-6731, 4820-01-202-0346. Verify interchangeability with system specifications before substitution.

What are the specifications of 4820-01-201-6599?

Key specifications for 4820-01-201-6599: Flange Seat to Disk End Height: 0.500 INCHES NOMINAL IN; Flange Diameter: 14.500 INCHES NOMINAL IN; Body Outside Diameter: 12.125 INCHES NOMINAL IN; Style Designator: PLAIN FLANGED. 8 specifications are documented in the U.S. Government catalog.

Is NSN 4820-01-201-6599 hazardous material?

No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.

Sources

U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.

U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.

✓ Data cited from the U.S. Government catalog; commercial cross-references from OEM and certified industry sources.

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