The Valve,safety Relief, cataloged under National Stock Number 4820-01-412-3900, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Northrop Grumman Systems Corporation. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-412-3900 |
| Primary Part Number | GV500AC2-90 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Connection Style | PLAIN (PIPE) ALL ENDS |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.250 INCHES ALL ENDS IN |
| Maximum Operating Temp | 121.0 CELSIUS SINGLE RESPONSE DEGC |
| Disk Loading Method | SPRING |
| Material | COPPER ALLOY BODY |
| Material | RUBBER PACKING |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 90.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| GV500AC2-90 | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| 559B-2M-90 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-412-3900 is a Valve,safety Relief, manufactured by Northrop Grumman Systems Corporation, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-412-3900 has 1 manufacturer part number on file: GV500AC2-90 (Northrop Grumman Systems Corporation).
Key specifications for GV500AC2-90: Connection Style: PLAIN (PIPE) ALL ENDS; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Style Designator: STRAIGHT THRU; Thread Direction: RIGHT-HAND 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.