The Valve,safety Relief, cataloged under National Stock Number 4820-01-156-3688, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 20 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-156-3688 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Furnished Items and Quantity | 1 LOCKING DEVICE |
| Connection Style | PLAIN,OPTIONAL END(PIPE) ALL ENDS |
| Connection Type | THREADED INTERNAL PIPE ALL ENDS |
| Style Designator | ANGLE |
| Operating Pressure | 10500.0 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 | -20.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 250.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Media for Which Designed | NITROGEN, GASEOUS FIFTH RESPONSE |
| Media for Which Designed | HYDROGEN THIRD RESPONSE |
| Media for Which Designed | HELIUM SECOND RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | GAS, NATURAL FOURTH RESPONSE |
| Material | RUBBER BUTADIENE-ACRYLONITRILE CLASS NBR SEAT |
| Material | STEEL COMP 303 BODY |
| Thread Series Designator | NPT ALL ENDS |
| Opening Pressure Setting | 6900.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL Q — CCL Item — Commerce Control List |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 11509713 | 7/2 Vendor item drawing reference Us Army Aviation and Missile Command |
| 5349T-2PP(L)-6900 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-156-3688 is a Valve,safety Relief, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-01-156-3688: Flow Control Device: POPPET; Furnished Items and Quantity: 1 LOCKING DEVICE; Connection Style: PLAIN,OPTIONAL END(PIPE) ALL ENDS; Connection Type: THREADED INTERNAL PIPE ALL ENDS. 20 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.
NSN 4820-01-156-3688 has DEMIL Code Q. Demilitarization may be required before disposal or transfer to non-military entities.
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.