The Valve,safety Relief, cataloged under National Stock Number 4820-01-351-5838, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Howell Laboratories Inc Dba Howell Laboratories Inc. Government technical data includes 14 specifications, cited from the U.S. Government catalog. The record lists 4 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-351-5838 |
| Primary Part Number | 5642 ITEM 21 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Howell Laboratories Inc Dba Howell Laboratories Inc |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Furnished Items and Quantity | 1 DEFLECTOR CAP |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Style Designator | STRAIGHT THRU |
| Adjustable Pressure Range | +14.0 TO 29.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 1.312 INCHES ALL ENDS IN |
| Disk Loading Method | SPRING |
| Thread Class | 3A ALL ENDS A |
| Thread Quantity Per Inch | 12 ALL ENDS |
| Material | STEEL COMP 303 BODY |
| Thread Series Designator | UN ALL ENDS |
| Valve Operation Method | AUTOMATIC |
| 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 |
|---|---|
| 5642 ITEM 21 | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| 5652C-4 | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| 5652C-G504 | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| 5652 ITEM 4 | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| Reference | Meaning |
|---|---|
| D559T-16D-20 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4820-01-351-5838 is a Valve,safety Relief, manufactured by Howell Laboratories Inc Dba Howell Laboratories Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-351-5838 has 4 manufacturer part numbers on file: 5642 ITEM 21 (Howell Laboratories Inc Dba Howell Laboratories Inc), 5652C-4 (Howell Laboratories Inc Dba Howell Laboratories Inc), 5652C-G504 (Howell Laboratories Inc Dba Howell Laboratories Inc), 5652 ITEM 4 (Howell Laboratories Inc Dba Howell Laboratories Inc).
Key specifications for 5642 ITEM 21: Flow Control Device: POPPET; Furnished Items and Quantity: 1 DEFLECTOR CAP; Connection Style: PLAIN (TUBE) ALL ENDS; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 14 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.