Armstrong Furnace RS35866B001 Cap Tube Assembly

The Armstrong Furnace RS35866B001 Cap Tube Assembly is a precise refrigerant metering device engineered for specific Armstrong Air and Allied Air residential cooling systems. This high-pressure capillary tube assembly ensures stable superheat values by regulating liquid refrigerant flow into the evaporator coil. Constructed with heavy-duty copper, the RS35866B001 is designed to withstand high-cycle stress and pressure fluctuations without fracturing. In the field, technicians rely on this OEM replacement part for critical refrigeration cycle repairs where maintaining the correct pressure drop is essential for system efficiency. This assembly interfaces directly with the liquid line distributor and is calibrated to match the specific BTU rating of the matching condenser and coil. Proper installation requires precise brazing techniques and a clean system to prevent debris from clogging the narrow metering orifices, ensuring peak HVAC heat transfer performance across the cooling circuit.

Technical Specifications & Key Benefits

• OEM Precision: Guaranteed compatibility with Allied Air and Armstrong furnace coil configurations.
• Optimized Refrigerant Control: Calibrated internal diameter for consistent mass flow rates.
• Durable Construction: High-grade copper tubing resists vibration fatigue and system pressure spikes.
• Field Serviceability: Direct-drop replacement designed to minimize HVAC repair downtime.
• System Efficiency: Maintains evaporator pressure to prevent coil icing and compressor liquid slugging.

Common Installation Questions

Is the RS35866B001 compatible with R-410A systems?
Yes, this assembly is engineered to handle the higher operating pressures associated with R-410A refrigerant cycles in modern high-efficiency units.

Does this assembly include the liquid line distributor?
This part consists of the capillary tube assembly; technicians should verify if the distributor body or additional spider tubes are required based on the specific coil model.

What causes a capillary tube to fail in an Armstrong unit?
Most failures result from system contamination or wax buildup due to moisture, which restricts flow and leads to improper suction pressure levels.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.