The Valve,safety Relief, cataloged under National Stock Number 4820-01-221-2049, 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 30 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through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-221-2049 |
| Primary Part Number | L-3210-B NMP-320 5T10PSI |
| 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 | 5.000 INCHES ALL ENDS IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Bolt Hole Nominal Diameter | 0.562 INCHES ALL ENDS IN |
| Operating Pressure | 150.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Valve Size | 2.500 INCHES IN |
| Adjustable Pressure Range | +5.0 TO 10.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 650.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 5.000 INCHES IN |
| Nominal Outside Diameter | 6.125 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 6 ALL ENDS |
| Bonnet Attachment Method | UNION |
| Media for Which Designed | STEAM SECOND RESPONSE |
| Media for Which Designed | WATER, FRESH THIRD RESPONSE |
| Media for Which Designed | AIR FIRST RESPONSE |
| First Connection Face to Centerline Distance | 6.000 INCHES IN |
| Material | STEEL BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL CORROSION RESISTING STEM |
| Raised Face Nominal Diameter | 4.000 INCHES ALL ENDS IN |
| Valve Operation Method | AUTOMATIC |
| Raised Face Nominal Height | 0.062 INCHES ALL ENDS IN |
| Nominal Thickness | 0.625 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 |
|---|---|
| L-3210-B NMP-320 5T10PSI PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| 3,129,404 5T10PSI | 5/2 Secondary reference U.S. Government activity |
| 3,129,404 | D/9 Drawing number reference only U.S. Government activity |
| L-3210-B NMP-320 5T10PSI | 5/9 Secondary reference Kunkle Industries Inc Lonergan Valve Div |
| L-3210-B NMP-320 5T10PSI | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| NMP-320 | D/9 Drawing number reference only Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| NMP-320 | 5/9 Secondary reference Kunkle Industries Inc Lonergan Valve Div |
NSN 4820-01-221-2049 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 4820-01-221-2049 has 1 manufacturer part number on file: L-3210-B NMP-320 5T10PSI (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-221-2122. Verify interchangeability with system specifications before substitution.
Key specifications for L-3210-B NMP-320 5T10PSI: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RAISED STRAIGHT ALL ENDS; Bolt Circle Nominal Diameter: 5.000 INCHES ALL ENDS IN. 30 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.