The Valve,safety Relief, cataloged under National Stock Number 4820-00-040-3134, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Lutron Electronics Co Inc. Government technical data includes 30 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government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 | 4820-00-040-3134 |
| Primary Part Number | 571973 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Lutron Electronics Co Inc |
| Status | ACTIVE |
| Flow Control Device | POPPET |
| Renewable Seat Ring Type | BONDED |
| Connection Style | FLARE(TUBE) FIRST END |
| Connection Style | GASKET SEAL(BOSS) SECOND END |
| Connection Style | DOUBLE THREADED SECTION BOSS FITTING GASKET WITH LOCKNUT SEALING (BOSS) FOURTH END |
| Style Designator | ANGLE |
| Nominal Outside Diameter Tube Accommodated | 0.500 INCHES FIRST END IN |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND THIRD END |
| Thread Direction | RIGHT-HAND FIRST END |
| Thread Direction | RIGHT-HAND FOURTH END |
| Nominal Thread Size | 0.437 INCHES SECOND END IN |
| Nominal Thread Size | 0.750 INCHES FIRST END IN |
| Nominal Thread Size | 0.437 INCHES THIRD END IN |
| Nominal Thread Size | 0.875 INCHES FOURTH END IN |
| Disk Loading Method | SPRING |
| Mounting Facility | BRACKET(S) |
| Surface Treatment | ANODIZE LOCATION NOT OTHERWISE SPECIFIED |
| Thread Class | 2A FOURTH END A |
| Thread Class | 2B FIRST END |
| Thread Class | 2B SECOND END |
| Thread Class | 2B THIRD END |
| Material | STEEL SEAT |
| Material | STEEL FLOW CONTROL DEVICE |
| Material | ALUMINUM BODY |
| Thread Series Designator | UNF FOURTH END |
| Thread Series Designator | UNF THIRD END |
| Thread Series Designator | UNF FIRST END |
| Thread Series Designator | UNF SECOND 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 |
|---|---|
| 571973 PRIMARY | Lutron Electronics Co Inc (USA) |
| 906004 | Essex Industries, Inc. Dba Essex Industries (USA) |
| Reference | Meaning |
|---|---|
| 222784 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
| 571973 | 5/9 Secondary reference Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| 222784 | 5/9 Secondary reference Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| 571973 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
| 571973 | 5/9 Secondary reference Stewart Industries Inc Bossert Machine Div |
NSN 4820-00-040-3134 is a Valve,safety Relief, manufactured by Lutron Electronics Co Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-040-3134 has 2 manufacturer part numbers on file: 571973 (Lutron Electronics Co Inc), 906004 (Essex Industries, Inc. Dba Essex Industries).
4 possible matches (shared part number, not a government interchangeability claim): 5961-00-137-7306, 5325-00-263-2711, 5310-01-340-6899. Verify interchangeability with system specifications before substitution.
Key specifications for 571973: Flow Control Device: POPPET; Renewable Seat Ring Type: BONDED; Connection Style: FLARE(TUBE) FIRST END; Connection Style: GASKET SEAL(BOSS) SECOND END. 30 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.