The Valve,safety Relief, cataloged under National Stock Number 4820-01-408-8991, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 24 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-408-8991 |
| Primary Part Number | NMP1569 L1 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Flange Shape | ROUND WITH HOLES FIRST END |
| Flange Shape | ROUND WITH HOLES SECOND END |
| Flange Face Design | RAISED STRAIGHT SECOND END |
| Flange Face Design | RAISED STRAIGHT FIRST END |
| Criticality Code Justification | ZZZY |
| Connection Type | FLANGE SECOND END |
| Connection Type | FLANGE FIRST END |
| Style Designator | ANGLE FLANGED ENDS |
| Material Document and Classification | ASTM A582 ASSN STD SINGLE MATERIAL RESPONSE STEM |
| Material Document and Classification | ASME SA-216 ASSN STD SINGLE MATERIAL RESPONSE BODY |
| Material Document and Classification | ASME SA-351 ASSN STD SINGLE MATERIAL RESPONSE SEAT |
| Material Document and Classification | ASTM A564 ASSN STD SINGLE MATERIAL RESPONSE FLOW CONTROL DEVICE |
| Operating Pressure | 1000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Maximum Operating Temp | 525.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 8.880 INCHES IN |
| Disk Loading Method | SPRING |
| First Connection Face to Centerline Distance | 10.440 INCHES IN |
| Material | STEEL BODY |
| Material | STEEL COMP 416 STEM |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL COMP 630 FLOW CONTROL DEVICE |
| Valve Operation Method | MANUAL |
| Reference Number Differentiating Characteristics | MATERIAL CONTROLLED IAW NAVSEA 0948-LP-045-7010 MATERIAL CONTROL STANDARD FOR LEVEL I ITEMS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL B — Remove Demilitarization Key Points |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| NMP1569 L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| NMP1569A01S0800 L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| NMP1569A01S0800 | 3/1 Design control — primary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| NMP1569 | 5/1 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-408-8991 is a Valve,safety Relief, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-408-8991 has 2 manufacturer part numbers on file: NMP1569 L1 (Naval Inventory Control Point Mechanicsburg), NMP1569A01S0800 L1 (Naval Inventory Control Point Mechanicsburg).
Key specifications for NMP1569 L1: Flow Control Device: DISK; Flange Shape: ROUND WITH HOLES FIRST END; Flange Shape: ROUND WITH HOLES SECOND END; Flange Face Design: RAISED STRAIGHT SECOND END. 24 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 4820-01-408-8991 has DEMIL Code B. 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.