Emerson Alco 066154 Expansion Valve

The Emerson Alco 066154 is a TFES 20 ZAA series thermal expansion valve engineered for high-capacity R410A systems. Specifically designed for 20-ton applications, this externally equalized TXV features a balanced port construction that ensures stable superheat control across varying ambient temperatures and evaporator loads. The 7/8" x 1 1/8" ODF sweat connections and straight body configuration facilitate direct integration into large-tonnage commercial air conditioning and heat pump units. Built with a durable stainless steel power element, the Emerson 066154 resists corrosion in demanding environments, protecting the system from premature valve failure.

For technicians in the field, the 10' capillary tube and wide range charge (ZAA) provide the necessary flexibility for remote bulb placement and consistent metering performance. This 20-ton expansion valve is a critical component for maintaining system efficiency and protecting the compressor from liquid slugging. When swapping out a failed unit, the replaceable power element and external superheat adjustment allow for precise tuning to meet specific OEM requirements without replacing the entire valve body.

• Balanced Port Design: Compensates for pressure fluctuations to maintain consistent superheat in 20-ton R410A systems.
• Corrosion Resistance: Features a stainless steel power element to prevent diaphragm fatigue and environmental degradation.
• Installation Flexibility: Equipped with a 10-foot capillary tube and 7/8" x 1 1/8" ODF solder connections for versatile piping layouts.
• Bi-Directional Capability: Suitable for both cooling-only and heat pump applications requiring externally equalized metering.
• Serviceable Components: Includes a replaceable power element to simplify long-term maintenance for HVAC contractors.

Is the Emerson 066154 compatible with older R22 systems?
No, this specific model is designed exclusively for R410A refrigerant. Using it with R22 will lead to improper metering and potential system damage due to incompatible pressure-temperature curves.

Where should the external equalizer line be connected?
The 1/4" ODF external equalizer must be connected to the suction line near the sensing bulb, typically downstream of the bulb, to accurately sense evaporator outlet pressure.

How do I adjust the superheat on this TFES series valve?
Superheat is adjusted via the external stem. Turning the stem clockwise increases superheat (decreases flow), while counter-clockwise decreases superheat (increases flow). Always allow 15-20 minutes for system stabilization between adjustments.

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.