The Valve,safety Relief, cataloged under National Stock Number 4820-01-237-0104, 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 23 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through both NSN and commercial part number lookups. 4 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 4820-01-237-0104 |
| Primary Part Number | L-3220-A21/2IPS 558T677PSI |
| 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 |
| Flange Face Design | RAISED STRAIGHT ALL ENDS |
| Bolt Circle Nominal Diameter | 5.500 INCHES ALL ENDS IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.750 INCHES ALL ENDS IN |
| Operating Pressure | 600.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 2.500 INCHES IN |
| Adjustable Pressure Range | +558.0 TO 677.0 POUNDS PER SQUARE INCH LBS |
| Maximum Operating Temp | 850.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 5.750 INCHES IN |
| Nominal Outside Diameter | 7.000 INCHES ALL ENDS IN |
| Bolt Hole Quantity | 4 ALL ENDS |
| Media for Which Designed | STEAM SINGLE RESPONSE |
| First Connection Face to Centerline Distance | 5.500 INCHES IN |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | STEEL CORROSION RESISTING STEM |
| Material | GLASS AND STEEL BODY |
| Raised Face Nominal Diameter | 4.125 INCHES ALL ENDS IN |
| Valve Operation Method | AUTOMATIC |
| Raised Face Nominal Height | 0.062 INCHES ALL ENDS IN |
| Nominal Thickness | 0.688 INCHES ALL ENDS IN |
| 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 |
|---|---|
| B-2185-S21/2IPS 558T677PSI | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| L-3220-A21/2IPS 558T677PSI PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| B-2185-S21/2IPS 558T677PSI | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| L-3220-A21/2IPS 558T677PSI | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| B-2185-S21/2IPS 558T677PSI | 5/9 Secondary reference Kunkle Industries Inc Lonergan Valve Div |
| L-3220-A21/2IPS 558T677PSI | 5/9 Secondary reference Kunkle Industries Inc Lonergan Valve Div |
NSN 4820-01-237-0104 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 4820-01-237-0104 has 2 manufacturer part numbers on file: B-2185-S21/2IPS 558T677PSI (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), L-3220-A21/2IPS 558T677PSI (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
Key specifications for L-3220-A21/2IPS 558T677PSI: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RAISED STRAIGHT ALL ENDS; Bolt Circle Nominal Diameter: 5.500 INCHES ALL ENDS IN. 23 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.