The Seat,valve, cataloged under National Stock Number 4820-01-171-4618, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Emerson Automation Solutions Final Control Us Lp Div Navy Product Team. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-171-4618 |
| Primary Part Number | A11521-001-156 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| Status | ACTIVE |
| Flange Seat to Disk End Height | 0.187 INCHES NOMINAL IN |
| Flange Diameter | 1.250 INCHES NOMINAL IN |
| Thread Length | 0.625 INCHES NOMINAL SINGLE THREADED PORTION IN |
| Style Designator | FAUCET |
| Body Inside Diameter | 1.250 INCHES NOMINAL IN |
| Nominal Thread Size | 1.750 INCHES SINGLE THREADED PORTION IN |
| Under Flange Height | 0.875 INCHES NOMINAL IN |
| Thread Class | 2A FIRST THREADED PORTION A |
| Thread Quantity Per Inch | 18 SINGLE THREADED PORTION |
| Material | STEEL COMP 303 BODY |
| Thread Series Designator | UNS FIRST THREADED PORTION |
| Seating Surface Shape | FLAT |
| 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 |
|---|---|
| A11521-001-156 PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| A11521-001-156 | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-171-4618 is a Seat,valve, manufactured by Emerson Automation Solutions Final Control Us Lp Div Navy Product Team, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-171-4618 has 1 manufacturer part number on file: A11521-001-156 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
Key specifications for A11521-001-156: Flange Seat to Disk End Height: 0.187 INCHES NOMINAL IN; Flange Diameter: 1.250 INCHES NOMINAL IN; Thread Length: 0.625 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: FAUCET. 12 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.