The Valve,relief, cataloged under National Stock Number 4820-01-102-1137, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Anderson Greenwood Lp Dba Anderson Greenwood Crosby. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-102-1137 |
| Primary Part Number | 20257,TYPE 1741-T,P/N 20257 EM41 |
| Item Name | Valve,relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | QUALITY CONTROL IN ACCORDANCE WITH NAVSHIPS 0948-045-7010 MATERIAL IDENTIFICATION AND CONTROL INSTRUCTION FOR LEVEL ONE ITEMS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| 20257,TYPE 1741-T,P/N 20257 EM41 | Anderson Greenwood Lp Dba Anderson Greenwood Crosby (USA) |
| Reference | Meaning |
|---|---|
| 20257EM41ML1 | 5/1 Secondary reference Naval Inventory Control Point Mechanicsburg |
| 20257EM41M | 3/1 Design control — primary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
NSN 4820-01-102-1137 is a Valve,relief, manufactured by Anderson Greenwood Lp Dba Anderson Greenwood Crosby, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-102-1137 has 1 manufacturer part number on file: 20257,TYPE 1741-T,P/N 20257 EM41 (Anderson Greenwood Lp Dba Anderson Greenwood Crosby).
1 possible match (shared part number, not a government interchangeability claim): 4820-01-180-8478. Verify interchangeability with system specifications before substitution.
Key specifications for 20257,TYPE 1741-T,P/N 20257 EM41: Criticality Code Justification: ZZZY; Reference Number Differentiating Characteristics: QUALITY CONTROL IN ACCORDANCE WITH NAVSHIPS 0948-045-7010 MATERIAL IDENTIFICATION AND CONTROL INSTRUCTION FOR LEVEL ONE ITEMS. 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.