NSN 4820-01-350-0201 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-350-0201. Manufacturer of record part number: 211054814.
The Seat,valve, cataloged under National Stock Number 4820-01-350-0201, 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 6 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 9 items share a part number with this NSN in the catalog (possible match — not a government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
4820-01-350-0201
Primary Part Number
211054814
Item Name
Seat,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Manufacturer
Naval Sea Systems Command
Status
ACTIVE
Body Outside Diameter
0.876 INCHES NOMINAL IN
Style Designator
PLAIN
Body Inside Diameter
0.375 INCHES NOMINAL IN
Seat Radius
0.344 INCHES NOMINAL IN
Material
PLASTIC POLYAMIDE NYLON OVERALL
Seating Surface Shape
RADIAL
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 Items9
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
4820-01-350-1522556-6408589-8POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-350-1644556-6408589-8,28POSSIBLE MATCH
PARTS KIT,BALL VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-350-1705556-6408589-18POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Naval Sea Systems Command
4810-01-492-982214509362POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-500-656814509361POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-500-688314509379POSSIBLE MATCH
VALVE,BALL
Possible match (shared part number)Naval Sea Systems Command
4820-01-645-2248556-6408589-8-ERDF330661D1POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-645-2252556-6408589-7-ERDF330661D1POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Naval Sea Systems Command
5360-01-645-5356556-6408589-38-ERDF330661D2POSSIBLE MATCH
SPRING,FLAT
Possible match (shared part number)Naval Sea Systems Command
Huntington Ingalls Inc Div Newport News Shipbuilding (USA)
Reference documents
Reference
Meaning
556-6408589
D/9Drawing number reference only
Naval Sea Systems Command
Related Parts
4820-01-350-1522POSSIBLE MATCH
SEAT,VALVE
556-6408589-8
4820-01-350-1644POSSIBLE MATCH
PARTS KIT,BALL VALVE
556-6408589-8,28
4820-01-350-1705POSSIBLE MATCH
STEM,FLUID VALVE
556-6408589-18
4810-01-492-9822POSSIBLE MATCH
STEM,FLUID VALVE
14509362
4820-01-500-6568POSSIBLE MATCH
STEM,FLUID VALVE
14509361
4820-01-500-6883POSSIBLE MATCH
VALVE,BALL
14509379
4820-01-645-2248POSSIBLE MATCH
SEAT,VALVE
556-6408589-8-ERDF330661D1
4820-01-645-2252POSSIBLE MATCH
SEAT,VALVE
556-6408589-7-ERDF330661D1
5360-01-645-5356POSSIBLE MATCH
SPRING,FLAT
556-6408589-38-ERDF330661D2
Frequently Asked Questions
What is NSN 4820-01-350-0201?
NSN 4820-01-350-0201 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 4820-01-350-0201?
NSN 4820-01-350-0201 has 3 manufacturer part numbers on file: 556-6408589-7 (Naval Sea Systems Command), 211054814 (Naval Sea Systems Command), DF330661 ITEM 7 (Huntington Ingalls Inc Div Newport News Shipbuilding).
What NSN replaces 4820-01-350-0201?
9 possible matches (shared part number, not a government interchangeability claim): 4820-01-350-1522, 4820-01-350-1644, 4820-01-350-1705. Verify interchangeability with system specifications before substitution.
What are the specifications of 211054814?
Key specifications for 211054814: Overall Height: 0.258 INCHES NOMINAL IN; Body Outside Diameter: 0.876 INCHES NOMINAL IN; Style Designator: PLAIN; Body Inside Diameter: 0.375 INCHES NOMINAL IN. 6 specifications are documented in the U.S. Government catalog.
Is NSN 4820-01-350-0201 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.