The Thermostat,flow Control, cataloged under National Stock Number 6685-00-768-3645, is classified within Federal Supply Class 6685 (Pressure, Temperature, and Humidity Measuring and Controlling Instruments) of the Instruments and Laboratory Equipment group. Government technical data includes 10 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 6685-00-768-3645 |
| Item Name | Thermostat,flow Control |
| FSC / FSG | 6685 / 66 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments |
| Status | ACTIVE |
| Flow Control Device | CHOKE |
| FSC Application Data | ENGINE INSTRUMENT |
| Spring Operated Pressure Relief | NOT PROVIDED |
| Largest Outside Diameter | 2.485 INCHES MINIMUM AND 2.495 INCHES MAXIMUM IN |
| Mounting Method | FLANGE |
| Valve Travel Distance | 0.500 INCHES NOMINAL IN |
| Operating Temp Rating | 173.0 FAHRENHEIT NOMINAL DEGF |
| Thermostat Type | BELLOWS |
| Usage Design | TO CONTROL ENGINE COOLANT TEMP |
| Opening Temp Rating | 158.0 FAHRENHEIT NOMINAL DEGF |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 216906R91 | 5/9 Secondary reference Navistar International Corporation Dba Navistar |
| 216906R91 | 3/2 Design control — primary reference U.S. Government activity |
| 216906R91 | 5/9 Secondary reference U.S. Government activity |
NSN 6685-00-768-3645 is a Thermostat,flow Control, classified under FSC 6685, Pressure, Temperature, and Humidity Measuring and Controlling Instruments. Status: active.
Key specifications for 6685-00-768-3645: Flow Control Device: CHOKE; Overall Height: 1.978 INCHES NOMINAL IN; FSC Application Data: ENGINE INSTRUMENT; Spring Operated Pressure Relief: NOT PROVIDED. 10 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.