The Valve,safety Relief, cataloged under National Stock Number 4820-00-005-4964, 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 11 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-005-4964 |
| Primary Part Number | 3978-5-33-0 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Howell Laboratories Inc Dba Howell Laboratories Inc |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END |
| Style Designator | STRAIGHT THRU |
| Adjustable Pressure Range | +25.0 TO 75.0 POUNDS PER SQUARE INCH LBS |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Thread Class | 3A FIRST END A |
| Material | ALUMINUM ALLOY OVERALL |
| Thread Series Designator | UNF FIRST END |
| Opening Pressure Setting | 33.0 POUNDS PER SQUARE INCH LBS |
| 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 |
|---|---|
| 3978-5-33-0 PRIMARY | Howell Laboratories Inc Dba Howell Laboratories Inc (USA) |
| Reference | Meaning |
|---|---|
| 3978-5 | 5/9 Secondary reference Howell Laboratories Inc Dba Howell Laboratories Inc |
NSN 4820-00-005-4964 is a Valve,safety Relief, manufactured by Howell Laboratories Inc Dba Howell Laboratories Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-005-4964 has 1 manufacturer part number on file: 3978-5-33-0 (Howell Laboratories Inc Dba Howell Laboratories Inc).
3 possible matches (shared part number, not a government interchangeability claim): 5815-00-097-6536, 7025-01-393-2589, 6105-01-582-7698. Verify interchangeability with system specifications before substitution.
Key specifications for 3978-5-33-0: Flow Control Device: DISK; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END; Style Designator: STRAIGHT THRU; Adjustable Pressure Range: +25.0 TO 75.0 POUNDS PER SQUARE INCH LBS. 11 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.