The Valve,safety Relief, cataloged under National Stock Number 4820-00-974-8619, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Johnson Controls, Inc Div Building Efficiency. Government technical data includes 15 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-974-8619 |
| Primary Part Number | A400-604 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Johnson Controls, Inc Div Building Efficiency |
| Status | ACTIVE |
| Flow Control Device | BALL |
| Connection Style | PLAIN (PIPE) FIRST END |
| Connection Type | THREADED EXTERNAL PIPE FIRST END |
| Style Designator | ANGLE |
| Bonnet Type | INSIDE SCREW |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.375 INCHES FIRST END IN |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| Material | COPPER ALLOY BODY |
| Material | STEEL CORROSION RESISTING FLOW CONTROL DEVICE |
| Material | COPPER ALLOY STEM |
| Material | COPPER ALLOY SEAT |
| Thread Series Designator | NPT FIRST END |
| 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 |
|---|---|
| A400-604 PRIMARY | Johnson Controls, Inc Div Building Efficiency (USA) |
| Reference | Meaning |
|---|---|
| 49-3280 | 5/9 Secondary reference Johnson Controls, Inc Div Building Efficiency |
NSN 4820-00-974-8619 is a Valve,safety Relief, manufactured by Johnson Controls, Inc Div Building Efficiency, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-974-8619 has 1 manufacturer part number on file: A400-604 (Johnson Controls, Inc Div Building Efficiency).
1 possible match (shared part number, not a government interchangeability claim): 5305-01-485-3727. Verify interchangeability with system specifications before substitution.
Key specifications for A400-604: Flow Control Device: BALL; Connection Style: PLAIN (PIPE) FIRST END; Connection Type: THREADED EXTERNAL PIPE FIRST END; Style Designator: ANGLE. 15 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.