The Valve,restrictor Check, cataloged under National Stock Number 4820-01-143-0093, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Atlantic Inertial Systems Limited. Government technical data includes 12 specifications, 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-143-0093 |
| Primary Part Number | 283550-1607 |
| Item Name | Valve,restrictor Check |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Atlantic Inertial Systems Limited |
| Status | ACTIVE |
| Connection Style | PLAIN, OPTIONAL END (PIPE) ALL ENDS |
| Mounting Position | HORIZONTAL |
| Supplementary Features | FLOW CONTROL DEVICE: NEEDLE |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Operating Pressure | 5000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 212.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Material | STEEL CORROSION RESISTING BODY |
| Thread Series Designator | NPTF ALL ENDS |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 283550-1607 | Atlantic Inertial Systems Limited (GBR) |
| 110533-001 | North Wind Test Llc (USA) |
| Reference | Meaning |
|---|---|
| ENL20SS | 5/9 Secondary reference Deltrol Corp Deltrol Controls Div |
| EN20SS | 3/2 Design control — primary reference U.S. Government activity |
| ENL20SS | 5/9 Secondary reference U.S. Government activity |
NSN 4820-01-143-0093 is a Valve,restrictor Check, manufactured by Atlantic Inertial Systems Limited, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-143-0093 has 2 manufacturer part numbers on file: 283550-1607 (Atlantic Inertial Systems Limited), 110533-001 (North Wind Test Llc).
1 possible match (shared part number, not a government interchangeability claim): 6625-01-462-5740. Verify interchangeability with system specifications before substitution.
Key specifications for 283550-1607: Connection Style: PLAIN, OPTIONAL END (PIPE) ALL ENDS; Mounting Position: HORIZONTAL; Supplementary Features: FLOW CONTROL DEVICE: NEEDLE; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 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.