The Seat,valve, cataloged under National Stock Number 4820-01-477-2533, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 2 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-477-2533 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | CLEANING, PACKAGING, AND MARKING IAW THE LATEST REVISION OF MIL-STD-1330 |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Reference | Meaning |
|---|---|
| 2640-801X2 PC 43 | 3/1 Design control — primary reference U.S. Government activity |
NSN 4820-01-477-2533 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-477-2964, 4820-01-493-4689, 4820-01-537-5815. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-477-2533: Criticality Code Justification: ZZZY; Special Features: INAVY: SEAT, BALL VALVE; End Item Identification: VALVE B 0.25IPS 4500PSI SWLDG CRES; VALVE, BALL 0.25IPS 4500PSI SOC WLD; Reference Number Differentiating Characteristics: CLEANING, PACKAGING, AND MARKING IAW THE LATEST REVISION OF MIL-STD-1330. 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.