The Disk,valve, cataloged under National Stock Number 4820-01-191-8539, 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. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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.
| Item Name | Disk,valve |
| FSC / FSG | 4820 — Valves, Nonpowered (FSG 48) |
| Manufacturers | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (CAGE 15187) |
| Parameter | Value |
|---|---|
| NSN | 4820-01-191-8539 |
| Primary Part Number | NS-3981 ASSEMBLY E FIND 21 |
| Item Name | Disk,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| 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 |
|---|---|
| NS-3981 ASSEMBLY E FIND 21 PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| S90014/300449 | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| NS-3981 | D/9 Drawing number reference only National Oilwell |
| NS-3981 ASSEMBLY E FIND 21 | 5/9 Secondary reference National Oilwell |
NSN 4820-01-191-8539 is a Disk,valve, manufactured by Emerson Automation Solutions Final Control Us Lp Div Navy Product Team, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-191-8539 has 2 manufacturer part numbers on file: NS-3981 ASSEMBLY E FIND 21 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), S90014/300449 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
3 possible matches (shared part number, not a government interchangeability claim): 5340-01-210-4188, 4820-01-210-4345, 4820-01-217-4707. 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.