The Stem,hydraulic Trip Assembly, cataloged under National Stock Number 4820-01-182-2711, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Siemens Energy, Inc.. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Stem,hydraulic Trip Assembly |
| FSC / FSG | 4820 — Valves, Nonpowered (FSG 48) |
| Manufacturers | Siemens Energy, Inc. (CAGE 16712) |
| Parameter | Value |
|---|---|
| NSN | 4820-01-182-2711 |
| Primary Part Number | MS159AT |
| Item Name | Stem,hydraulic Trip Assembly |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Siemens Energy, Inc. |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| D-58985 PIECE 23 | Siemens Energy, Inc. (USA) |
| MS159AT PRIMARY | Siemens Energy, Inc. (USA) |
| Reference | Meaning |
|---|---|
| D-58985 | D/9 Drawing number reference only Siemens Energy, Inc. |
NSN 4820-01-182-2711 is a Stem,hydraulic Trip Assembly, manufactured by Siemens Energy, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-182-2711 has 2 manufacturer part numbers on file: D-58985 PIECE 23 (Siemens Energy, Inc.), MS159AT (Siemens Energy, Inc.).
2 possible matches (shared part number, not a government interchangeability claim): 2825-01-182-2712, 5342-01-182-4501. Verify interchangeability with system specifications before substitution.
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.