The Indicator,valve Opening, cataloged under National Stock Number 4820-01-520-6449, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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.
| Parameter | Value |
|---|---|
| NSN | 4820-01-520-6449 |
| Primary Part Number | 7108102-OA-176 |
| Item Name | Indicator,valve Opening |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Diameter | 4.560 INCHES NOMINAL IN |
| Material | COPPER ALLOY CASE |
| Pointer Purpose | OPEN AND SHUT |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 845-7108102-OA-176 | Naval Sea Systems Command (USA) |
| 7108102-OA-176 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 7108102 | D/9 Drawing number reference only Naval Sea Systems Command |
NSN 4820-01-520-6449 is a Indicator,valve Opening, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-520-6449 has 2 manufacturer part numbers on file: 845-7108102-OA-176 (Naval Sea Systems Command), 7108102-OA-176 (Naval Sea Systems Command).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-520-6547, 4820-01-550-2145, 4820-01-727-8336. Verify interchangeability with system specifications before substitution.
Key specifications for 7108102-OA-176: Diameter: 4.560 INCHES NOMINAL IN; Special Features: THIS IS ONE OF THREE MAJOR COMPONENTS OF A MECHANICAL POSITION INDICATOR ON THE GEARBOX/ACTUATOR FOR A 4" BALL VALVE. THIS ITEM HAS RED ENAMAL PAINTED AREA THAT ALIGNS WITH A INDICATOR PLATE (FIND 173) WITH OPEN/SHUT MARKINGS AT 90 DEG TO EACH OTHER. THE THIRD COMPONENT IS A FLANGE-LIKE ITEM CALLED AN INDICATOR.; Part Name Assigned by Controlling Agency: INDICATOR DISK; Material: COPPER ALLOY CASE. 3 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.
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.