The Seat,valve, cataloged under National Stock Number 4820-01-549-4255, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 2 specifications, cited from the U.S. Government catalog. The record lists 6 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-549-4255 |
| Primary Part Number | 7550478-264140501-065D0 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | MATERIAL CONTROLLED IAW SS800-AG-MAN-010/P9290 SYSTEM CERTIFICATION PROCEDURES AND CRITERIA MANUAL FOR DEEP SUBMERGENCE SYSTEMS AND REQUIRES CLEANING, PACKING, AND MARKING IAW MIL-STD-1622 OR MIL-STD-1330 AS DEEMED APPLICABLE; CRITICAL ITEM FOR SAFETY AND SURVIVAL OF DEEP SUBMERGENCE RESEARCH AND RESCUE VEHICALS AS DIFFERENTIATED BY SPECIAL TEST FEATURES |
| 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 |
|---|---|
| 7550478-264140501-065D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| 2641-405-01 ITEM 65D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| G547-0002-264140501-065D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| 2640-801X2 PIECE 46D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| 264140501-065D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| 2640-801X2 ITEM 46D0 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 7550478-264140501-065 | 3/1 Design control — primary reference Naval Sea Systems Command |
| 2640-801X2 PIECE 46 | 5/1 Secondary reference U.S. Government activity |
| 2640-801X2 ITEM 46 | 5/1 Secondary reference U.S. Government activity |
| G547-0002-264140501-065 | 5/1 Secondary reference U.S. Government activity |
| 2641-405-01 ITEM 65 | 5/1 Secondary reference U.S. Government activity |
| 264140501-065 | 5/1 Secondary reference U.S. Government activity |
NSN 4820-01-549-4255 is a Seat,valve, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-549-4255 has 6 manufacturer part numbers on file: 7550478-264140501-065D0 (Naval Inventory Control Point Mechanicsburg), 2641-405-01 ITEM 65D0 (Naval Inventory Control Point Mechanicsburg), G547-0002-264140501-065D0 (Naval Inventory Control Point Mechanicsburg), 2640-801X2 PIECE 46D0 (Naval Inventory Control Point Mechanicsburg), 264140501-065D0 (Naval Inventory Control Point Mechanicsburg) and 1 more.
Key specifications for 7550478-264140501-065D0: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: MATERIAL CONTROLLED IAW SS800-AG-MAN-010/P9290 SYSTEM CERTIFICATION PROCEDURES AND CRITERIA MANUAL FOR DEEP SUBMERGENCE SYSTEMS AND REQUIRES CLEANING, PACKING, AND MARKING IAW MIL-STD-1622 OR MIL-STD-1330 AS DEEMED APPLICABLE; CRITICAL ITEM FOR SAFETY AND SURVIVAL OF DEEP SUBMERGENCE RESEARCH AND RESCUE VEHICALS AS DIFFERENTIATED BY SPECIAL TEST FEATURES. 2 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 4820-01-549-4255 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.