The Valve,safety Relief, cataloged under National Stock Number 4820-01-448-1419, 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 28 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-448-1419 |
| Primary Part Number | 20327 PART 20327H51SS |
| 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 |
| Furnished Items and Quantity | 1 WRENCH |
| Flange Face Design | RAISED STRAIGHT ALL ENDS |
| Bolt Circle Nominal Diameter | 3.125 INCHES ALL ENDS IN |
| Connection Type | FLANGE ALL ENDS |
| Style Designator | ANGLE FLANGED ENDS |
| Material Document and Classification | ASTM A216 GR WCB ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | ASTM A582 TY 303 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Material Document and Classification | ASTM A582 TY 303 ASSN STD SINGLE MATERIAL RESPONSE STEM |
| Material Document and Classification | ASTM A582 TYPE 303 ASSN STD SINGLE MATERIAL RESPONSE SEAT |
| Bolt Hole Nominal Diameter | 0.625 INCHES ALL ENDS IN |
| Operating Pressure | 250.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Operating Pressure | 285.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Valve Size | 1.000 INCHES IN |
| Adjustable Pressure Range | +45.0 TO 55.0 POUNDS PER SQUARE INCH LBS |
| Maximum Operating Temp | 300.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Maximum Operating Temp | 100.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 3.250 INCHES IN |
| Nominal Outside Diameter | 4.250 INCHES ALL ENDS IN |
| Mounting Facility | BRACKET(S) |
| Bolt Hole Quantity | 4 ALL ENDS |
| First Connection Face to Centerline Distance | 3.500 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 | 2.000 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 |
|---|---|
| TYPE FF 2751 1.00 IN. | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| 20327 PART 20327H51SS PRIMARY | Emerson Automation Solutions Final Control Us Lp Div Navy Product Team (USA) |
| Reference | Meaning |
|---|---|
| TYPE FF 2751 1.00 IN. | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| 20327 | D/9 Drawing number reference only Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| CNSNN05SEE | 5/9 Secondary reference Danco Valve Company |
| 20327H51SS | C/1 Advisory reference — outside the item-of-supply concept Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| 20327 PART 20327H51SS | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-448-1419 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 4820-01-448-1419 has 2 manufacturer part numbers on file: TYPE FF 2751 1.00 IN. (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team), 20327 PART 20327H51SS (Emerson Automation Solutions Final Control Us Lp Div Navy Product Team).
1 possible match (shared part number, not a government interchangeability claim): 6240-01-463-5865. Verify interchangeability with system specifications before substitution.
Key specifications for 20327 PART 20327H51SS: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES ALL ENDS; Furnished Items and Quantity: 1 WRENCH; Flange Face Design: RAISED STRAIGHT ALL ENDS. 28 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 4820-01-448-1419 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.