The Valve,safety Relief, cataloged under National Stock Number 4820-01-183-1539, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 2 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 4820-01-183-1539 |
| Primary Part Number | 2745-S4 1/2IN2920T3575PSICP |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | CLEANING IN ACCORDANCE WITH MIL-C-52211 |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| 2745-S4 1/2IN2920T3575PSICP | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 2745-S4 1/2IN2920T3575PSI | 3/1 Design control — primary reference Curtiss-Wright Flow Control Corporation Dba Farris Engineering Div Curtiss-Wright Valves Division- Farris |
NSN 4820-01-183-1539 is a Valve,safety Relief, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-183-1539 has 1 manufacturer part number on file: 2745-S4 1/2IN2920T3575PSICP (Naval Inventory Control Point Mechanicsburg).
Key specifications for 2745-S4 1/2IN2920T3575PSICP: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: CLEANING IN ACCORDANCE WITH MIL-C-52211. 2 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.