NSN 4820-01-103-3290 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-103-3290. Manufacturer of record part number: 803-4385049-X-043.
Flange Seat to Disk End Height: 1.375 INCHES NOMINAL IN
Flange Diameter: 12.234 INCHES NOMINAL IN
Body Outside Diameter: 10.234 INCHES NOMINAL IN
Body Stepped Inside Diameter: 7.750 INCHES NOMINAL THIRD STEP IN
Body Stepped Inside Diameter: 8.000 INCHES NOMINAL SECOND STEP IN
Body Stepped Inside Diameter: 9.000 INCHES NOMINAL FIRST STEP IN
Style Designator: PLAIN FLANGED
Identification
NSN: 4820-01-103-3290
NIIN: 011033290
FSC: 4820 — Valves, Nonpowered
FSG: 48 — Valves
Primary part number: 803-4385049-X-043
Manufacturer: Naval Sea Systems Command
General Description
The Seat,valve, cataloged under National Stock Number 4820-01-103-3290, 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 11 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 9 items share a part number with this NSN in the catalog (possible match — not a government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
4820-01-103-3290
Primary Part Number
803-4385049-X-043
Item Name
Seat,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Manufacturer
Naval Sea Systems Command
Status
ACTIVE
Flange Seat to Disk End Height
1.375 INCHES NOMINAL IN
Flange Diameter
12.234 INCHES NOMINAL IN
Body Outside Diameter
10.234 INCHES NOMINAL IN
Body Stepped Inside Diameter
7.750 INCHES NOMINAL THIRD STEP IN
Body Stepped Inside Diameter
8.000 INCHES NOMINAL SECOND STEP IN
Body Stepped Inside Diameter
9.000 INCHES NOMINAL FIRST STEP IN
Style Designator
PLAIN FLANGED
Under Flange Height
13.313 INCHES NOMINAL IN
Material
COPPER ALLOY OVERALL
Seat Angle in Deg
45.000 NOMINAL
Seating Surface Shape
ANGULAR
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL Q — CCL Item — Commerce Control List
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.
4820-01-103-3329810-4385049 ITEM 29POSSIBLE MATCH
STOP,ACTUATOR
Possible match (shared part number)Naval Ship Systems Command
4820-01-103-3330810-4385049-X-053POSSIBLE MATCH
CAP,CONNECTING ROD
Possible match (shared part number)Naval Ship Systems Command
4820-01-103-3331803-4385049-X-034POSSIBLE MATCH
RETAINER,DOWEL
Possible match (shared part number)Naval Ship Systems Command
4820-01-103-3385810-4385049-X-012POSSIBLE MATCH
CAP,VALVE
Possible match (shared part number)Naval Ship Systems Command
4820-01-103-3436810-4385049-X-037POSSIBLE MATCH
DISK,VALVE
Possible match (shared part number)Naval Ship Systems Command
4820-01-111-5698803-4385049-X-095POSSIBLE MATCH
RETAINER,DOWEL
Possible match (shared part number)Naval Ship Systems Command
4810-01-113-3738810-4385049-B-054POSSIBLE MATCH
CRANKSHAFT,VALVE
Possible match (shared part number)Naval Ship Systems Command
4810-01-113-4202810-4385049-B-020POSSIBLE MATCH
LINK,ADJUSTING
Possible match (shared part number)Naval Ship Systems Command
4810-01-113-5381810-4385049-X-048POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Naval Ship Systems Command
NSN 4820-01-103-3290 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 4820-01-103-3290?
NSN 4820-01-103-3290 has 1 manufacturer part number on file: 803-4385049-X-043 (Naval Sea Systems Command).
What NSN replaces 4820-01-103-3290?
9 possible matches (shared part number, not a government interchangeability claim): 4820-01-103-3329, 4820-01-103-3330, 4820-01-103-3331. Verify interchangeability with system specifications before substitution.
What are the specifications of 803-4385049-X-043?
Key specifications for 803-4385049-X-043: Flange Seat to Disk End Height: 1.375 INCHES NOMINAL IN; Flange Diameter: 12.234 INCHES NOMINAL IN; Body Outside Diameter: 10.234 INCHES NOMINAL IN; Body Stepped Inside Diameter: 7.750 INCHES NOMINAL THIRD STEP IN. 11 specifications are documented in the U.S. Government catalog.
Is NSN 4820-01-103-3290 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.
What is the DEMIL code for NSN 4820-01-103-3290?
NSN 4820-01-103-3290 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
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.