The Valve,expansion, cataloged under National Stock Number 4820-00-256-6680, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Emerson Electric Co Alco Controls Div. Government technical data includes 26 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 6 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-256-6680 |
| Primary Part Number | TCLN1FW |
| Item Name | Valve,expansion |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Emerson Electric Co Alco Controls Div |
| Status | ACTIVE |
| Flow Control Device | DISK, TOP GUIDED |
| Valve Equalizer Location | INTERNAL |
| Temp Rating | 250.0 FAHRENHEIT DEGF |
| Second End Relationship with First End | NOT IDENTICAL |
| Body Style | ANGLE GIVE "ADQM" OR "ADQN" IF FLANGED ONE OR TWO ENDS |
| First End Style Designator | BEVELED |
| Bulb Length | 3.562 INCHES NOMINAL IN |
| Bulb Diameter | 0.625 INCHES NOMINAL IN |
| Mounting Method | CLAMP BULB |
| Refrigeration Capacity in Btu Per Hour | 15.6 |
| End Connection Quantity | 2 |
| Capillary Tube Length | 120.000 INCHES NOMINAL IN |
| Second End Style Designator | BEVELED |
| First End Connection Type | BUTT WELD TUBE |
| Valve Evaporator Temp Range Designation | LOW |
| Bulb Media Type | REFRIGERANT 12 |
| First End Outside Diameter Tube Accommodated | 0.375 INCHES NOMINAL IN |
| Material | COPPER ALLOY BODY |
| Material | STEEL FLOW CONTROL DEVICE |
| Material | STEEL STEM |
| Material | COPPER ALLOY SEAT |
| Valve Expansion Control Type | THERMOSTATIC |
| Media for Which Designed | REFRIGERANT 12 |
| Valve Pressure Limiting Device | NOT INCLUDED |
| Second End Connection Type | BUTT WELD TUBE |
| Second End Outside Diameter Tube Accommodated | 0.500 INCHES NOMINAL IN |
| 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 |
|---|---|
| TCLN1FW PRIMARY | Emerson Electric Co Alco Controls Div (USA) |
| TCLN1FW | Williams and Co Inc (USA) |
| Reference | Meaning |
|---|---|
| F2045 | 5/9 Secondary reference Emerson Electric Co Alco Controls Div |
| TCLN00FA10C | 5/9 Secondary reference Emerson Electric Co Alco Controls Div |
| TCLN100FA2C | 5/9 Secondary reference Emerson Electric Co Alco Controls Div |
| TCLN1FW | 5/9 Secondary reference Progress Supply, Inc. |
| F23046 | D/9 Drawing number reference only Emerson Electric Co Alco Controls Div |
NSN 4820-00-256-6680 is a Valve,expansion, manufactured by Emerson Electric Co Alco Controls Div, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-00-256-6680 has 2 manufacturer part numbers on file: TCLN1FW (Emerson Electric Co Alco Controls Div), TCLN1FW (Williams and Co Inc).
6 possible matches (shared part number, not a government interchangeability claim): 4820-00-256-6684, 4820-01-195-6362, 4820-01-450-7646. Verify interchangeability with system specifications before substitution.
Key specifications for TCLN1FW: Flow Control Device: DISK, TOP GUIDED; Valve Equalizer Location: INTERNAL; Temp Rating: 250.0 FAHRENHEIT DEGF; Second End Relationship with First End: NOT IDENTICAL. 26 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.