NSN 4820-01-318-9745 — this item is cataloged by the U.S. Government under National Stock Number 4820-01-318-9745. Manufacturer of record part number: 255721 PIECE 107.
Manufacturer of record: Huntington Ingalls Inc Div Newport News Shipbuilding
Identification
NSN: 4820-01-318-9745
NIIN: 013189745
FSC: 4820 — Valves, Nonpowered
FSG: 48 — Valves
Primary part number: 255721 PIECE 107
Manufacturer: Huntington Ingalls Inc Div Newport News Shipbuilding
General Description
The Retainer,disk,valve, cataloged under National Stock Number 4820-01-318-9745, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Huntington Ingalls Inc Div Newport News Shipbuilding. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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
4820-01-318-9745
Primary Part Number
255721 PIECE 107
Item Name
Retainer,disk,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Manufacturer
Huntington Ingalls Inc Div Newport News Shipbuilding
Status
ACTIVE
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 Items3
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
4820-01-359-2831255722 PIECE 14POSSIBLE MATCH
SPRING,REMOTE CONTROL LEVER
Possible match (shared part number)Huntington Ingalls Inc Div Newport News Shipbuilding
4820-01-448-9575255721 PIECE 106POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Huntington Ingalls Inc Div Newport News Shipbuilding
4330-01-504-612225572-1POSSIBLE MATCH
PNEUMATIC MUFFLER,EXHAUST-INTAKE
Possible match (shared part number)Hutchinson Aerospace & Industry, Inc. Dba Barry Wright Corp
Huntington Ingalls Inc Div Newport News Shipbuilding (USA)
Reference documents
Reference
Meaning
255721
D/9Drawing number reference only
Huntington Ingalls Inc Div Newport News Shipbuilding
Related Parts
4820-01-359-2831POSSIBLE MATCH
SPRING,REMOTE CONTROL LEVER
255722 PIECE 14
4820-01-448-9575POSSIBLE MATCH
SEAT,VALVE
255721 PIECE 106
4330-01-504-6122POSSIBLE MATCH
PNEUMATIC MUFFLER,EXHAUST-INTAKE
25572-1
Frequently Asked Questions
What is NSN 4820-01-318-9745?
NSN 4820-01-318-9745 is a Retainer,disk,valve, manufactured by Huntington Ingalls Inc Div Newport News Shipbuilding, classified under FSC 4820, Valves, Nonpowered. Status: active.
What part numbers are listed for NSN 4820-01-318-9745?
NSN 4820-01-318-9745 has 1 manufacturer part number on file: 255721 PIECE 107 (Huntington Ingalls Inc Div Newport News Shipbuilding).
What NSN replaces 4820-01-318-9745?
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-359-2831, 4820-01-448-9575, 4330-01-504-6122. Verify interchangeability with system specifications before substitution.
What are the specifications of 255721 PIECE 107?
Key specifications for 255721 PIECE 107: Special Features: CRES QQ-S-763,CLASS 316,COND A. 0 specifications are documented in the U.S. Government catalog.
Is NSN 4820-01-318-9745 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.