The Valve,safety Relief, cataloged under National Stock Number 4820-01-520-4351, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Mission Systems Orchard Park Inc. Government technical data includes 24 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-520-4351 |
| Primary Part Number | B16511-3 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Mission Systems Orchard Park Inc |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Flange Face Design | RAISED STRAIGHT ALL ENDS |
| Bolt Circle Nominal Diameter | 4.750 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 | 85.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Valve Size | 2.000 INCHES IN |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 150.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 5.000 INCHES IN |
| Nominal Outside Diameter | 6.000 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 4 ALL ENDS |
| Bonnet Attachment Method | BOLTED |
| Test Data Document | MIL-STD-167-1 BY COMMANDER NAVAL SEA SYSTEMS LETTER 9514 SER 05L2/027. 22 FEB 2002 STANDARD (INCLUDES INDUSTRY OR ASSOCIATION STANDARDS, INDIVIDUAL MANUFACTUREER STANDARDS, ETC.). |
| First Connection Face to Centerline Distance | 5.000 INCHES IN |
| Material | STEEL CORROSION RESISTING BODY |
| Raised Face Nominal Diameter | 3.620 INCHES ALL ENDS IN |
| Opening Pressure Setting | 75.0 POUNDS PER SQUARE INCH LBS |
| Valve Operation Method | AUTOMATIC |
| Raised Face Nominal Height | 0.060 INCHES ALL ENDS IN |
| Nominal Thickness | 0.750 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 |
|---|---|
| B16511-3 PRIMARY | Mission Systems Orchard Park Inc (USA) |
NSN 4820-01-520-4351 is a Valve,safety Relief, manufactured by Mission Systems Orchard Park Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-520-4351 has 1 manufacturer part number on file: B16511-3 (Mission Systems Orchard Park Inc).
Key specifications for B16511-3: Flow Control Device: POPPET; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RAISED STRAIGHT ALL ENDS; Bolt Circle Nominal Diameter: 4.750 INCHES ALL ENDS IN. 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.
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.