NSN 4820-01-475-8250 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-475-8250. Manufacturer of record part number: 845-7286645 ITEM 29.
The Seat,valve, cataloged under National Stock Number 4820-01-475-8250, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 2 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 6 items share a part number with this NSN in the catalog (possible match — not a government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
4820-01-475-8250
Primary Part Number
845-7286645 ITEM 29
Item Name
Seat,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Manufacturer
Naval Sea Systems Command
Status
ACTIVE
Style Designator
PLAIN
Material
PLASTIC POLYTETRAFLUOROETHYLENE OVERALL
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 Items6
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
4820-01-477-66152643-820-03 ITEM 25,29POSSIBLE MATCH
PARTS KIT,BALL VALVE
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-477-84912643-820-03 ITEM 61POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-477-84922643-820-03 ASSY RDPOSSIBLE MATCH
ASSY ROD
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-549-63817550478-264382003-029POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-627-9871845-7286645 ITEM 63POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Naval Sea Systems Command
NSN 4820-01-475-8250 is a Seat,valve, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
What part numbers are listed for NSN 4820-01-475-8250?
NSN 4820-01-475-8250 has 1 manufacturer part number on file: 845-7286645 ITEM 29 (Naval Sea Systems Command).
What NSN replaces 4820-01-475-8250?
6 possible matches (shared part number, not a government interchangeability claim): 4820-01-477-6615, 4820-01-477-8491, 4820-01-477-8492. Verify interchangeability with system specifications before substitution.
What are the specifications of 845-7286645 ITEM 29?
Key specifications for 845-7286645 ITEM 29: Overall Height: 0.372 INCHES NOMINAL IN; Style Designator: PLAIN; Special Features: LEVEL 1 NAVSEA; End Item Identification: E/I BALL VALVE .50; .75; OR 1 INCH TOP LOAD IN. 2 specifications are documented in the U.S. Government catalog.
Is NSN 4820-01-475-8250 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.