The Valve,ball, cataloged under National Stock Number 4820-01-137-8180, 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. Government technical data includes 19 specifications, cited from the U.S. Government catalog. The record lists 3 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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.
| Parameter | Value |
|---|---|
| NSN | 4820-01-137-8180 |
| Primary Part Number | 255948ASSEMBLYAT2IN |
| Item Name | Valve,ball |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Huntington Ingalls Inc Div Newport News Shipbuilding |
| Status | ACTIVE |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Furnished Items and Quantity | 1 TAILPIECE |
| Flange Face Design | PLAIN ALL ENDS |
| Bolt Circle Nominal Diameter | 4.438 INCHES ALL ENDS IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | STRAIGHT THRU FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.688 INCHES ALL ENDS IN |
| Valve Size | 2.000 INCHES IN |
| Maximum Operating Temp | 150.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Nominal Outside Diameter | 5.562 INCHES FIRST END IN |
| Bolt Hole Quantity | 6 ALL ENDS |
| Face to Face Distance | 9.875 INCHES IN |
| Media for Which Designed | WATER, SALT SINGLE RESPONSE |
| Material | NICKEL ALLOY STEM |
| Material | PLASTIC SEAT |
| Material | NICKEL ALLOY BODY |
| Material | TITANIUM FLOW CONTROL DEVICE |
| Valve Operation Method | MANUAL |
| Nominal Thickness | 0.844 INCHES ALL ENDS IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL B — Remove Demilitarization Key Points |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| 255948ASSEMBLYAT2IN PRIMARY | Huntington Ingalls Inc Div Newport News Shipbuilding (USA) |
| 255948 ASSY-AT-2IN PRIMARY | Huntington Ingalls Inc Div Newport News Shipbuilding (USA) |
| 255948 ASSY-AT-2IN. PRIMARY | Derbyshire Machine & Tool Co (USA) |
| Reference | Meaning |
|---|---|
| 2640-645 | D/9 Drawing number reference only U.S. Government activity |
| 2640-645 ASSEMBLY AT | 3/2 Design control — primary reference U.S. Government activity |
| 255948 | D/9 Drawing number reference only Huntington Ingalls Inc Div Newport News Shipbuilding |
| 255948 ASSY-AT-2IN. | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-137-8180 is a Valve,ball, manufactured by Huntington Ingalls Inc Div Newport News Shipbuilding, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-137-8180 has 3 manufacturer part numbers on file: 255948ASSEMBLYAT2IN (Huntington Ingalls Inc Div Newport News Shipbuilding), 255948 ASSY-AT-2IN (Huntington Ingalls Inc Div Newport News Shipbuilding), 255948 ASSY-AT-2IN. (Derbyshire Machine & Tool Co).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-184-4496, 4820-01-187-1993, 4820-01-235-8601. Verify interchangeability with system specifications before substitution.
Key specifications for 255948ASSEMBLYAT2IN: Flange Shape: ROUND WITH HOLES ALL ENDS; Furnished Items and Quantity: 1 TAILPIECE; Flange Face Design: PLAIN ALL ENDS; Bolt Circle Nominal Diameter: 4.438 INCHES ALL ENDS IN. 19 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4820-01-137-8180 has DEMIL Code B. Demilitarization may be required before disposal or transfer to non-military entities.
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.