The Valve,safety Relief, cataloged under National Stock Number 4820-00-821-9001, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Ashcroft Inc Dba Heise. Government technical data includes 24 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 11 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-821-9001 |
| Primary Part Number | 1664 |
| Item Name | Valve,safety Relief |
| FSC / FSG | 4820 / 48 — No Item Name Available |
| Manufacturer | Ashcroft Inc Dba Heise |
| Status | ACTIVE |
| Valve Discharge Flow Rate | 33.0 CUBIC FEET PER MINUTE |
| Material | COPPER ALLOY BODY |
| Thread Quantity Per Inch | 18 FIRST END |
| Disk Loading Method | SPRING |
| Flow Control Device | POPPET |
| Features Provided | PRESSURE TIGHT OUTLET SIDE |
| Valve Operation Method | AUTOMATIC |
| Thread Direction | RIGHT-HAND FIRST END |
| Maximum Operating Temp | 450.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Nominal Pipe Size Accommodated | 0.250 INCHES FIRST END IN |
| Thread Series Designator | NPT FIRST END |
| Operating Pressure | 275.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SECOND RESPONSE LBS |
| Opening Pressure Setting | 30.0 POUNDS PER SQUARE INCH LBS |
| Style Designator | STRAIGHT THRU |
| Material | COPPER ALLOY STEM |
| Material | COPPER ALLOY SEAT |
| Maximum Operating Temp | 450.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Operating Pressure | 275.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM FIRST RESPONSE LBS |
| Connection Type | THREADED INTERNAL PIPE FIRST END |
| Nominal Thread Size | 0.250 INCHES FIRST END IN |
| Reference Number Differentiating Characteristics | AS DIFFERENTIATED BY VALVE SIZE AND SET PRESSURE |
| Media for Which Designed | AIR FIRST RESPONSE |
| Media for Which Designed | GAS, INERT SECOND RESPONSE |
| Connection Style | PLAIN,OPTIONAL END(PIPE) FIRST END |
| Acquisition Status | ACTIVE |
| HAZMAT | No |
| Part Number | Manufacturer |
|---|---|
| 1664 | Ashcroft Inc Dba Heise (USA) |
NSN 4820-00-821-9001 is a Valve,safety Relief, manufactured by Ashcroft Inc Dba Heise, classified under FSC 4820 (No Item Name Available). Status: active.
NSN 4820-00-821-9001 has 1 cross-referenced part number: 1664 (Ashcroft Inc Dba Heise).
There are 11 known substitutes for 4820-00-821-9001: 6115-00-235-8679, 4820-00-287-4087, 5965-00-338-4259 and 8 more. Verify interchangeability with system specifications before substitution.
Key specifications for 1664: Valve Discharge Flow Rate: 33.0 CUBIC FEET PER MINUTE; Material: COPPER ALLOY BODY; Thread Quantity Per Inch: 18 FIRST END; Disk Loading Method: SPRING. 24 total characteristics are documented in the Federal Logistics Information System.