The Flapper,valve, cataloged under National Stock Number 4820-00-866-9972, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
Catalog Facts
Item Name
Flapper,valve
FSC / FSG
4820 — Valves, Nonpowered (FSG 48)
Technical Specifications
Parameter
Value
NSN
4820-00-866-9972
Item Name
Flapper,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Status
ACTIVE
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL Q — CCL Item — Commerce Control List
Hazard
No hazard code in the DLA record (HMIC N)
⇄Related Items4
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
5340-01-048-998651921POSSIBLE MATCH
BUMPER
Possible match (shared part number)L3 Technologies, Inc. Div L3 Keo
3120-01-239-718151921POSSIBLE MATCH
BEARING,WASHER,THRUST
Possible match (shared part number)Ingersoll-Rand Co Material Handling Div
9540-01-300-288151921POSSIBLE MATCH
ANGLE,STRUCTURAL
Possible match (shared part number)Aluminum Co of America
4730-01-335-5998POSSIBLE MATCH
STRAINER ELEMENT,SEDIMENT
Possible match (shared part number)
Cross-Reference Index
No manufacturer part numbers on file in the U.S. Government catalog.
Reference documents
Reference
Meaning
51921
3/2Design control — primary reference
U.S. Government activity
Related Parts
5340-01-048-9986POSSIBLE MATCH
BUMPER
51921
3120-01-239-7181POSSIBLE MATCH
BEARING,WASHER,THRUST
51921
9540-01-300-2881POSSIBLE MATCH
ANGLE,STRUCTURAL
51921
4730-01-335-5998POSSIBLE MATCH
STRAINER ELEMENT,SEDIMENT
Frequently Asked Questions
What is NSN 4820-00-866-9972?
NSN 4820-00-866-9972 is a Flapper,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
What NSN replaces 4820-00-866-9972?
4 possible matches (shared part number, not a government interchangeability claim): 5340-01-048-9986, 3120-01-239-7181, 9540-01-300-2881. Verify interchangeability with system specifications before substitution.
Is NSN 4820-00-866-9972 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 4820-00-866-9972?
NSN 4820-00-866-9972 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.