The Cap,valve, cataloged under National Stock Number 4820-01-129-7781, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 1 specification, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government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.
Technical Specifications
Parameter
Value
NSN
4820-01-129-7781
Item Name
Cap,valve
FSC / FSG
4820 / 48 — Valves, Nonpowered
Status
ACTIVE
Material
STEEL CORROSION RESISTING
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 Items4
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
4730-01-132-91284788433-0003APOSSIBLE MATCH
TEE,TUBE
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
4820-01-144-028387791-4602 ITEM 25POSSIBLE MATCH
INDICATOR,VALVE OPENING
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
4320-01-146-1089516-4788433 ITEM 2POSSIBLE MATCH
FLANGE MANIFOLD,PUMP
Possible match (shared part number)Naval Ship Systems Command
4820-01-189-88214788433-0027POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
Cross-Reference Index
No manufacturer part numbers on file in the U.S. Government catalog.
Reference documents
Reference
Meaning
516-4788433
D/9Drawing number reference only
U.S. Government activity
4788433-0009
C/1Advisory reference — outside the item-of-supply concept
U.S. Government activity
87791-4602 ITEM 9
5/2Secondary reference
U.S. Government activity
516-4788433 ITEM 9
3/2Design control — primary reference
U.S. Government activity
Related Parts
4730-01-132-9128POSSIBLE MATCH
TEE,TUBE
4788433-0003A
4820-01-144-0283POSSIBLE MATCH
INDICATOR,VALVE OPENING
87791-4602 ITEM 25
4320-01-146-1089POSSIBLE MATCH
FLANGE MANIFOLD,PUMP
516-4788433 ITEM 2
4820-01-189-8821POSSIBLE MATCH
STEM,FLUID VALVE
4788433-0027
Frequently Asked Questions
What is NSN 4820-01-129-7781?
NSN 4820-01-129-7781 is a Cap,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
What NSN replaces 4820-01-129-7781?
4 possible matches (shared part number, not a government interchangeability claim): 4730-01-132-9128, 4820-01-144-0283, 4320-01-146-1089. Verify interchangeability with system specifications before substitution.
What are the specifications of 4820-01-129-7781?
Key specifications for 4820-01-129-7781: Material: STEEL CORROSION RESISTING. 1 specification is documented in the U.S. Government catalog.
Is NSN 4820-01-129-7781 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.