Emerson Alco 097719 Control Valve

The Emerson Alco 097719, also known as the EX4-I21, is a high-performance stepper motor driven electrical control valve engineered for precise refrigerant mass flow management. Designed for veteran contractors, this bipolar stepper motor valve provides continuous modulation across a 10% to 100% capacity range, making it ideal for superheat control, hot gas bypass, and liquid injection. Featuring a 3/8" x 5/8" sweat ODF connection and a 24Vdc supply voltage, this unit utilizes chemical-resistant ceramic slide and ports to eliminate mechanical wear and ensure repeatable accuracy. With a maximum working pressure of 870 psig and positive shut-off capability, it functions effectively as both an electronic expansion valve (EEV) and a solenoid valve, reducing system complexity. The fully hermetic stainless steel body and direct coupling mechanism provide long-term reliability in demanding HVACR refrigeration systems. Installers should note the 750-step resolution and 1.5-second full stroke time for optimal tuning with Emerson universal drivers.

• Precise Mass Flow: Stepper motor technology ensures accurate refrigerant flow control and stable superheat across varying loads.
• Multi-Purpose Utility: Operates as an expansion valve, suction pressure regulator, or liquid level controller for maximum versatility.
• Zero Leakage Design: Features positive shut-off to prevent migration, removing the need for an external solenoid valve.
• High Durability: Constructed with a stainless steel body and ceramic internal components to resist corrosion and high-velocity wear.
• Fast Response: Achieves full stroke travel in 1.5 seconds, providing rapid correction for system hunting or load spikes.

Is the EX4-I21 compatible with CO2 systems?
Yes, this valve is rated for subcritical CO2 applications with a maximum operating pressure differential (MOPD) of 580 psid.

Does this valve require a specific driver?
The EX4-I21 requires a bipolar stepper motor driver, such as the Emerson EXD series or comparable 24Vdc controllers, to manage the 500mA phase current.

Can this valve be used in bi-flow applications?
While the EX4 series has bi-flow versions (e.g., EX4-U31), the standard EX4-I21 is a uni-flow design; always verify the flow arrow direction during brazing.

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.