The Valve,safety Relief, cataloged under National Stock Number 4820-01-261-4126, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Hydrasearch Company, Llc. Government technical data includes 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-261-4126 |
| Primary Part Number | TP-6VR57-3 PL-2287 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Hydrasearch Company, Llc |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Type | THREADED EXTERNAL PIPE ALL ENDS |
| Operating Pressure | 6000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +750.0 TO 3500.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.500 INCHES ALL ENDS IN |
| Material | COPPER ALLOY BODY |
| Material | STEEL COMP 304 SEAT |
| Material | STEEL COMP 304 FLOW CONTROL DEVICE |
| Thread Series Designator | NPT ALL ENDS |
| 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 |
|---|---|
| TP-6VR57-3 PL-2287 PRIMARY | Hydrasearch Company, Llc (USA) |
| Reference | Meaning |
|---|---|
| TP-6VR57-3 PL-2 | C/1 Advisory reference — outside the item-of-supply concept Naval Inventory Control Point Mechanicsburg |
NSN 4820-01-261-4126 is a Valve,safety Relief, manufactured by Hydrasearch Company, Llc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-261-4126 has 1 manufacturer part number on file: TP-6VR57-3 PL-2287 (Hydrasearch Company, Llc).
Key specifications for TP-6VR57-3 PL-2287: Flow Control Device: DISK; Connection Type: THREADED EXTERNAL PIPE ALL ENDS; Operating Pressure: 6000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS; Adjustable Pressure Range: +750.0 TO 3500.0 POUNDS PER SQUARE INCH LBS. 10 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.