The Valve,safety Relief, cataloged under National Stock Number 4820-01-129-5561, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Anderson Greenwood Lp Dba Anderson Greenwood Crosby. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-129-5561 |
| Primary Part Number | 9666-007-91M |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| Status | ACTIVE |
| Flow Control Device | STEM |
| Flange Shape | ROUND WITH HOLES ALL ENDS |
| Flange Face Design | RECESSED STRAIGHT SECOND END |
| Flange Face Design | PLAIN FIRST END |
| 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 SINGLE RESPONSE LBS |
| Valve Size | 2.500 INCHES IN |
| Adjustable Pressure Range | +56.0 TO 65.0 POUNDS PER SQUARE INCH LBS |
| Bonnet Type | INSIDE SPRING |
| Maximum Operating Temp | 425.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Second Connection Face to Centerline Distance | 5.500 INCHES IN |
| Disk Loading Method | SPRING |
| Bolt Hole Quantity | 6 ALL ENDS |
| Bonnet Attachment Method | BOLTED |
| Media for Which Designed | OIL FIRST RESPONSE |
| Media for Which Designed | WATER, FRESH SECOND RESPONSE |
| First Connection Face to Centerline Distance | 5.500 INCHES IN |
| Material | NICKEL ALLOY STEM |
| Valve Operation Method | AUTOMATIC |
| Nominal Thickness | 0.500 INCHES ALL ENDS IN |
| Recess Nominal Diameter | 2.710 INCHES SECOND END 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 |
|---|---|
| 9666-007-91M PRIMARY | Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA) |
| Reference | Meaning |
|---|---|
| 9666 | D/9 Drawing number reference only Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-129-5561 is a Valve,safety Relief, manufactured by Anderson Greenwood Lp Dba Anderson Greenwood Crosby, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-129-5561 has 1 manufacturer part number on file: 9666-007-91M (Anderson Greenwood Lp Dba Anderson Greenwood Crosby).
5 possible matches (shared part number, not a government interchangeability claim): 4820-01-130-2375, 4820-01-130-4783, 4820-01-131-4893. Verify interchangeability with system specifications before substitution.
Key specifications for 9666-007-91M: Flow Control Device: STEM; Flange Shape: ROUND WITH HOLES ALL ENDS; Flange Face Design: RECESSED STRAIGHT SECOND END; Flange Face Design: PLAIN FIRST 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.
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.