The Retainer,seat,valve, cataloged under National Stock Number 4820-01-505-0518, 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 5 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-505-0518 |
| Primary Part Number | 2643-405-01 ITEM 53CP |
| Item Name | Retainer,seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Material Document and Classification | QQ-S-763 CL 304 COND A FED SPEC SINGLE MATERIAL RESPONSE |
| Valve Design Control Activity | 53711 |
| Material | STEEL CORROSION RESISTING |
| Reference Number Differentiating Characteristics | CLEANING, PACKAGING, AND MARKING IAW MIL-STD-1330D |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| 2643-405-01 ITEM 53CP | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 7285244 | D/9 Drawing number reference only Naval Sea Systems Command |
| 2643-405-01 ITEM 53 | 5/1 Secondary reference U.S. Government activity |
| 7285244 ITEM 53 | 3/1 Design control — primary reference Naval Sea Systems Command |
| 2643-405-01 | D/9 Drawing number reference only U.S. Government activity |
NSN 4820-01-505-0518 is a Retainer,seat,valve, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-505-0518 has 1 manufacturer part number on file: 2643-405-01 ITEM 53CP (Naval Inventory Control Point Mechanicsburg).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-732-5566. Verify interchangeability with system specifications before substitution.
Key specifications for 2643-405-01 ITEM 53CP: Criticality Code Justification: ZZZY; Material Document and Classification: QQ-S-763 CL 304 COND A FED SPEC SINGLE MATERIAL RESPONSE; Special Features: THIS RING SEAT RETAINER IS DESIGNED FOR .25, .50, AND 1.00 INCH. VALVE ASSEMBLY--BALL AIR BLEED TYPE. TWO RING SEAT RETAINERS ARE REQUIRED PER VALVE ASSEMBLY. IN; Valve Design Control Activity: 53711. 5 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.