The Ring,seat Retainer, cataloged under National Stock Number 4820-01-135-9920, 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2 specifications, cited from the U.S. Government catalog. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-135-9920 |
| Item Name | Ring,seat Retainer |
| 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 |
|---|---|
| 2640-405X3 PIECE 29CP | 5/1 Secondary reference Naval Inventory Control Point Mechanicsburg |
| SS845-2050967 PIECE 29CP | 5/1 Secondary reference Naval Inventory Control Point Mechanicsburg |
| 2640-405X3 PIECE 29 | 5/1 Secondary reference U.S. Government activity |
| SS845-2050967 PIECE 29 | 3/1 Design control — primary reference U.S. Government activity |
NSN 4820-01-135-9920 is a Ring,seat Retainer, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 4820-01-164-7187. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-01-135-9920: Criticality Code Justification: ZZZY; 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.