AKV 20-5 (042H2029) Danfoss Electric Expansion Valve

Product Overview

The AKV 20-5 (042H2029) is a high-capacity, electronically operated expansion valve designed for precise refrigerant injection in large-scale industrial and commercial refrigeration systems. Operating on the Pulse Width Modulation (PWM) principle, the Danfoss 042H2029 (042H2029) serves a critical dual function: it acts as both an expansion device and a liquid line solenoid valve. This integration is essential for B2B applications such as industrial chillers, large-scale cold storage, and supermarket rack systems, where maintaining an exact superheat (SH) is vital for maximizing evaporator efficiency and ensuring compressor safety. The "Type 5" designation identifies this model as having the highest capacity within the AKV 20 series framework.

Technical Configuration

The AKV 20-5 utilizes a robust 13.5 mm actuator system specifically designed for high-frequency cycling. Unlike traditional modulating valves, the 042H2029 cycles fully open and fully closed; the refrigerant flow is precisely managed by the ratio between the open and closed duration (duty cycle). This mechanical simplicity ensures a hermetic, durable construction capable of withstanding tens of millions of cycles. With a Maximum Working Pressure (PS) of 28 bar (406 psig), it is compatible with a wide range of fluorinated refrigerants (HFC/HCFC), providing a reliable and fast-acting solution for modern cooling infrastructures.

Technical Specifications

Technical FAQs

What are the specific advantages of PWM control for high-capacity evaporators?

In high-capacity systems, PWM control ensures that when the valve is open, the refrigerant velocity remains high. This optimizes the heat transfer coefficient and assists in effective oil return to the compressor, which is often superior to the partial-throttling behavior of traditional mechanical expansion valves.

Does this valve require an additional solenoid valve for safety?

No. The AKV 20-5 is a Normally Closed (NC) valve that provides a reliable, hermetic seal when de-energized. This eliminates the need for a separate liquid line solenoid valve, reducing system complexity, potential leak points, and installation costs.

Can the AKV 20-5 handle low-temperature applications?

Yes. With an ambient and fluid temperature rating down to -40 Celsius and a moisture-protected 13.5 mm actuator, this valve is ideal for blast freezers and low-temperature cold storage environments.

Engineering & Installation Guide

• Filtration and System Cleanliness: Due to the high-frequency cycling of the PWM mechanism, it is mandatory to install a high-quality filter drier (such as the Danfoss DML or DCL series) immediately upstream. Even small particles can cause abrasive wear on the high-capacity orifice or prevent the needle from sealing properly.

• Brazing Thermal Protection: During the installation of the solder connections, the valve body must be wrapped in a wet cloth. The internal temperature must be kept below 100 Celsius to prevent permanent damage to the precision-engineered seals and the actuator housing.

• Electrical Configuration: Ensure the solenoid coil (sold separately) matches the output voltage of the Danfoss ADAP-KOOL controller. The coil should be mounted with the cable entry pointing downwards (drip loop) to prevent moisture from traveling into the electrical actuator interface.