The Valve,safety Relief, cataloged under National Stock Number 4820-01-151-3685, 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. Government technical data includes 25 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-151-3685 |
| Primary Part Number | 20273RS41M |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND ALL ENDS |
| Flange Face Design | PLAIN ALL ENDS |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Material Document and Classification | QQ-N-288 FED SPEC SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | QQ-C-390,ALLOY D4/D/ FED SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE STEM |
| Operating Pressure | 250.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 2.000 INCHES IN |
| Adjustable Pressure Range | +156.0 TO 180.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 150.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 4.750 INCHES IN |
| Nominal Outside Diameter | 6.500 INCHES ALL ENDS IN |
| Bonnet Attachment Method | BOLTED |
| Media for Which Designed | WATER-OIL-GAS SINGLE RESPONSE |
| First Connection Face to Centerline Distance | 4.750 INCHES IN |
| Material | COPPER ALLOY BODY |
| Material | NICKEL ALLOY STEM |
| Material | NICKEL ALLOY FLOW CONTROL DEVICE |
| Material | NICKEL ALLOY SEAT |
| Valve Operation Method | AUTOMATIC |
| Nominal Thickness | 0.875 INCHES ALL ENDS IN |
| 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 |
| Part Number | Manufacturer |
|---|---|
| 20273RS41M PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| 20273RS41M | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-151-3685 is a Valve,safety Relief, manufactured by Emerson Automation Solutions Final Control Us Lp Div Navy Product Team, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-151-3685 has 1 manufacturer part number on file: 20273RS41M (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
Key specifications for 20273RS41M: Flow Control Device: DISK; Flange Shape: ROUND ALL ENDS; Flange Face Design: PLAIN ALL ENDS; Connection Type: FLANGE ALL ENDS. 25 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 4820-01-151-3685 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.