The Valve,safety Relief, cataloged under National Stock Number 4820-01-470-5738, 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 21 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-470-5738 |
| Primary Part Number | LL-2120-C .50IN 191T255PSI |
| 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 WITH HOLES ALL ENDS |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Material Document and Classification | MIL-B-16541 MIL SPEC SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | QQ-B-657 FED SPEC SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | QQ-B-657 FED SPEC SINGLE MATERIAL RESPONSE STEM |
| Operating Pressure | 400.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 0.500 INCHES IN |
| Bonnet Type | INSIDE SCREW |
| Maximum Operating Temp | 180.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 2.500 INCHES IN |
| Disk Loading Method | SPRING |
| Media for Which Designed | WATER, SALT FIRST RESPONSE |
| Media for Which Designed | WASTE PRODUCT SECOND RESPONSE |
| First Connection Face to Centerline Distance | 2.500 INCHES IN |
| Material | COPPER ALLOY BODY |
| Material | COPPER ALLOY STEM |
| Material | COPPER ALLOY SEAT |
| Valve Discharge Flow Rate | 24.0 GALLONS PER MINUTE |
| 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 |
|---|---|
| LL-2120-C .50IN 191T255PSI PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| CDS-549 ITEM 11 | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| CDS-549 ITEM 11 | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| LL-2120-C .50IN 191T255PSI | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| LL-2120-C .50IN | C/1 Advisory reference — outside the item-of-supply concept Kunkle Industries Inc Lonergan Valve Div |
| NMP-1078 | D/9 Drawing number reference only Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-470-5738 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 4820-01-470-5738 has 2 manufacturer part numbers on file: LL-2120-C .50IN 191T255PSI (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), CDS-549 ITEM 11 (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
Key specifications for LL-2120-C .50IN 191T255PSI: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Connection Type: FLANGE ALL ENDS; Style Designator: ANGLE FLANGED ENDS. 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.