The Plug,seat Retaining, cataloged under National Stock Number 4820-01-240-5536, 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 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-240-5536 |
| Primary Part Number | 257388, PIECE 2 L1 |
| Item Name | Plug,seat Retaining |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | QUALITY CONTROL IN ACCORDANCE WITH NAVSHIPS 0948-045-7010 MATERIAL IDENTIFICATION AND CONTROL INSTRUCTION FOR LEVEL 1 ITEMS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| 257388, PIECE 2 L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| 257389 L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 257389 | 5/1 Secondary reference Huntington Ingalls Inc Div Newport News Shipbuilding |
| 257388, PIECE 2 | 3/1 Design control — primary reference Huntington Ingalls Inc Div Newport News Shipbuilding |
NSN 4820-01-240-5536 is a Plug,seat Retaining, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-240-5536 has 2 manufacturer part numbers on file: 257388, PIECE 2 L1 (Naval Inventory Control Point Mechanicsburg), 257389 L1 (Naval Inventory Control Point Mechanicsburg).
Key specifications for 257388, PIECE 2 L1: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: QUALITY CONTROL IN ACCORDANCE WITH NAVSHIPS 0948-045-7010 MATERIAL IDENTIFICATION AND CONTROL INSTRUCTION FOR LEVEL 1 ITEMS. 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.
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.