The Valve,safety Relief, cataloged under National Stock Number 4820-01-250-1535, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Lockheed Martin Corporation Div Rms - Mitchel Field. Government technical data includes 21 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-250-1535 |
| Primary Part Number | 1206916 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Lockheed Martin Corporation Div Rms - Mitchel Field |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY. |
| Operating Pressure | 200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.562 INCHES ALL ENDS IN |
| Maximum Operating Temp | 280.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | -40.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Surface Treatment | ANODIZE LOCATION NOT OTHERWISE SPECIFIED |
| Media for Which Designed | HELIUM FIFTH RESPONSE |
| Media for Which Designed | FUEL/OIL, HYDROCARBON FOURTH RESPONSE |
| Media for Which Designed | ALCOHOL, ETHYL SECOND RESPONSE |
| Media for Which Designed | AMMONIA, GASEOUS THIRD RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | ALUMINUM BODY |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| Opening Pressure Setting | 2.0 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 |
|---|---|
| 1206916 | Lockheed Martin Corporation Div Rms - Mitchel Field (USA) |
| Reference | Meaning |
|---|---|
| 942645 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 5942645 | 7/1 Vendor item drawing reference Naval Sea Systems Command |
| 559A-6D-2 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-250-1535 is a Valve,safety Relief, manufactured by Lockheed Martin Corporation Div Rms - Mitchel Field, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-250-1535 has 1 manufacturer part number on file: 1206916 (Lockheed Martin Corporation Div Rms - Mitchel Field).
Key specifications for 1206916: Flow Control Device: POPPET; Connection Style: PLAIN (TUBE) ALL ENDS; Connection Type: THREADED EXTERNAL TUBE ALL ENDS; Style Designator: STRAIGHT THRU NOTE: TO BE USED FOR VALVE BODIES OF ONE SECTION ONLY.. 21 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.