The Plunger Ball, cataloged under National Stock Number 4820-01-475-3957, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 10 items share a part number with this NSN in the catalog (possible match — not a government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
4820-01-475-3957
Item Name
Plunger Ball
FSC / FSG
4820 / 48 — Valves, Nonpowered
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 Items10
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
4820-01-475-3992845-6655309 ITEM 5-1POSSIBLE MATCH
CAP,VALVE
Possible match (shared part number)Naval Sea Systems Command
4820-01-475-4033845-6655309 ITEM 6-1POSSIBLE MATCH
BALL GUIDE
Possible match (shared part number)Naval Sea Systems Command
4820-01-475-4040845-6655309 ITEM 1-1POSSIBLE MATCH
SEAT GUIDE
Possible match (shared part number)Naval Sea Systems Command
5315-01-477-6788845-6655309 ITEM 2-2POSSIBLE MATCH
PIN,GROOVED,HEADED
Possible match (shared part number)Naval Sea Systems Command
5315-01-477-6791845-6655309 ITEM 3-2POSSIBLE MATCH
PIN,GROOVED,HEADED
Possible match (shared part number)Naval Sea Systems Command
5315-01-477-76742640-682-09 ITEM 20-2POSSIBLE MATCH
PIN,STRAIGHT,HEADED
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
5340-01-477-77692640-682-09 ITEM 16-1POSSIBLE MATCH
COVER,ACCESS
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
5340-01-477-9026845-6655309 ITEM 17-1POSSIBLE MATCH
COVER,ACCESS
Possible match (shared part number)Naval Sea Systems Command
4820-01-477-94472640-682-09 ITEM 9POSSIBLE MATCH
BALLADAPTER
Possible match (shared part number)Electric Boat Corporation Div General Dynamics Electric Boat
5315-01-481-9572845-6655309 ITEM 21-5POSSIBLE MATCH
PIN,SPRING
Possible match (shared part number)Naval Sea Systems Command
Cross-Reference Index
No manufacturer part numbers on file in the U.S. Government catalog.
Reference documents
Reference
Meaning
SSBL-54N
5/9Secondary reference
U.S. Government activity
845-6655309 ITEM 6-2
5/9Secondary reference
Naval Sea Systems Command
2640-682-09 ITEM 6-2
5/9Secondary reference
U.S. Government activity
SSBL-54N
3/2Design control — primary reference
U.S. Government activity
845-6655309
D/9Drawing number reference only
Naval Sea Systems Command
Related Parts
4820-01-475-3992POSSIBLE MATCH
CAP,VALVE
845-6655309 ITEM 5-1
4820-01-475-4033POSSIBLE MATCH
BALL GUIDE
845-6655309 ITEM 6-1
4820-01-475-4040POSSIBLE MATCH
SEAT GUIDE
845-6655309 ITEM 1-1
5315-01-477-6788POSSIBLE MATCH
PIN,GROOVED,HEADED
845-6655309 ITEM 2-2
5315-01-477-6791POSSIBLE MATCH
PIN,GROOVED,HEADED
845-6655309 ITEM 3-2
5315-01-477-7674POSSIBLE MATCH
PIN,STRAIGHT,HEADED
2640-682-09 ITEM 20-2
5340-01-477-7769POSSIBLE MATCH
COVER,ACCESS
2640-682-09 ITEM 16-1
5340-01-477-9026POSSIBLE MATCH
COVER,ACCESS
845-6655309 ITEM 17-1
4820-01-477-9447POSSIBLE MATCH
BALLADAPTER
2640-682-09 ITEM 9
5315-01-481-9572POSSIBLE MATCH
PIN,SPRING
845-6655309 ITEM 21-5
Frequently Asked Questions
What is NSN 4820-01-475-3957?
NSN 4820-01-475-3957 is a Plunger Ball, classified under FSC 4820, Valves, Nonpowered. Status: active.
What NSN replaces 4820-01-475-3957?
10 possible matches (shared part number, not a government interchangeability claim): 4820-01-475-3992, 4820-01-475-4033, 4820-01-475-4040. Verify interchangeability with system specifications before substitution.
What are the specifications of 4820-01-475-3957?
Key specifications for 4820-01-475-3957: End Item Identification: TOOL ASSEMBLY DISASSEMBLY TOP LOADED BALL VAIVH HIGH PRESSURE. 0 specifications are documented in the U.S. Government catalog.
Is NSN 4820-01-475-3957 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.