The Cover,steam Seal Rear, cataloged under National Stock Number 4820-01-168-6437, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Siemens Energy, Inc.. Government technical data includes 1 specification, 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-168-6437 |
| Primary Part Number | F7757 PIECE 28 |
| Item Name | Cover,steam Seal Rear |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Siemens Energy, Inc. |
| Status | ACTIVE |
| General Characteristics Item Description | STEEL |
| 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 |
|---|---|
| F7757 PIECE 28 PRIMARY | Siemens Energy, Inc. (USA) |
| M549ZG PRIMARY | Siemens Energy, Inc. (USA) |
| Reference | Meaning |
|---|---|
| F7757 | D/9 Drawing number reference only Siemens Energy, Inc. |
NSN 4820-01-168-6437 is a Cover,steam Seal Rear, manufactured by Siemens Energy, Inc., classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-168-6437 has 2 manufacturer part numbers on file: F7757 PIECE 28 (Siemens Energy, Inc.), M549ZG (Siemens Energy, Inc.).
3 possible matches (shared part number, not a government interchangeability claim): 4820-01-168-7616, 2825-01-170-2486, 2825-01-170-2487. Verify interchangeability with system specifications before substitution.
Key specifications for F7757 PIECE 28: General Characteristics Item Description: STEEL. 1 specification is 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.