The Valve,safety Relief, cataloged under National Stock Number 4820-00-446-3321, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 25 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through both NSN and commercial part number lookups. 49 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-446-3321 |
| Primary Part Number | YMS135S49-53PC143T0154 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Flow Control Device | DISK |
| Nominal Pipe Size Accommodated | 0.500 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 0.500 INCHES FIRST END IN |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Connection Style | PLAIN (PIPE) SECOND END |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Connection Type | THREADED EXTERNAL PIPE SECOND END |
| Style Designator | ANGLE |
| Operating Pressure | 1200.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Adjustable Pressure Range | +500.0 TO 700.0 POUNDS PER SQUARE INCH LBS |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Bonnet Type | INSIDE SPRING |
| Thread Direction | RIGHT-HAND SECOND END |
| Thread Direction | RIGHT-HAND FIRST END |
| Nominal Thread Size | 0.500 INCHES SECOND END IN |
| Nominal Thread Size | 0.500 INCHES FIRST END IN |
| Maximum Operating Temp | 300.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Disk Loading Method | SPRING |
| Bonnet Attachment Method | THREADED |
| Media for Which Designed | WATER, FRESH SINGLE RESPONSE |
| Material | STEEL CORROSION RESISTING SEAT |
| Material | STEEL CORROSION RESISTING BODY |
| Thread Series Designator | NPT SECOND END |
| 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 |
|---|---|
| YMS135S49-53PC143T0154 | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| N508PC143T0154 | 5/9 Secondary reference Ingersoll Rand Co |
| AM82S49-153PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| PC461S49-220PC143T0154 | 5/9 Secondary reference Naval Sea Systems Command |
| AT96S49-13PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| YMS135S49-45PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| N355PC143T0154 | 5/9 Secondary reference Ingersoll Rand Co |
| AM82S49-0161PC143T0154 | 5/9 Secondary reference Naval Sea Systems Command |
| N343PC143T0154 | 5/9 Secondary reference Ingersoll Rand Co |
| AT96S49-13PC143T0154 | 5/9 Secondary reference Naval Sea Systems Command |
| N367PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| AM82S49-0153PC143T0154 | 5/9 Secondary reference Naval Sea Systems Command |
| N500PC143T0154 | 5/9 Secondary reference Siemens Energy, Inc. Dba Dresser-Rand |
| AT96S49-5PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| N335PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| N534PC143T0154 | 5/9 Secondary reference Siemens Energy, Inc. Dba Dresser-Rand |
| 20M-1 1/2 IN-500PSI | 5/9 Secondary reference Anderson Greenwood Lp Dba Anderson Greenwood Crosby |
| N347PC143T0154 | 5/9 Secondary reference U.S. Government activity |
| N367PC143T0154 | 5/9 Secondary reference Siemens Energy, Inc. Dba Dresser-Rand |
| YMS135S49-45PC143T0154 | 5/9 Secondary reference Naval Sea Systems Command |
| N359PC143T0154 | 5/9 Secondary reference Ingersoll Rand Co |
NSN 4820-00-446-3321 is a Valve,safety Relief, manufactured by Naval Sea Systems Command, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-446-3321 has 1 manufacturer part number on file: YMS135S49-53PC143T0154 (Naval Sea Systems Command).
Key specifications for YMS135S49-53PC143T0154: Flow Control Device: DISK; Nominal Pipe Size Accommodated: 0.500 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 0.500 INCHES FIRST END IN; Connection Style: PLAIN,OPTIONAL END(PIPE) FIRST END. 25 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.