The AKV 20-4 (042H2028) is a high-performance, electronically operated expansion valve designed for precise refrigerant injection in commercial and industrial refrigeration systems. Operating on a Pulse Width Modulation (PWM) principle, the Danfoss 042H2028 (042H2028) serves a dual purpose: it acts as both an expansion device and a liquid line solenoid valve. This integration is vital for B2B applications such as large-scale supermarket refrigeration, cold storage, and process cooling, where tight superheat (SH) control is required to maximize evaporator efficiency and protect the compressor from liquid slugging. The "Type 4" designation identifies this as a high-capacity unit within the AKV 20 series.
The AKV 20-4 utilizes a specialized 13.5 mm actuator system, engineered to interface seamlessly with Danfoss ADAP-KOOL controllers. Unlike traditional modulating valves that change needle depth, the 042H2028 cycles fully open and fully closed at specific intervals; the flow rate is precisely managed by the duration of the "open" time. This design results in a robust, hermetic valve with fewer moving parts, capable of millions of cycles. Rated for a Maximum Working Pressure (PS) of 28 bar (406 psig), it is compatible with a broad range of fluorinated refrigerants (HFC/HCFC), ensuring versatility across modern cooling infrastructures.
| Feature | Specification |
| Model | AKV 20-4 (042H2028) |
| Brand | Danfoss |
| Product Type | Electric Expansion Valve (PWM) |
| Actuator System | 13.5 mm |
| Max Working Pressure (PS) | 28 bar (406 psig) |
| Max Test Pressure | 42 bar |
| Ambient Temp Range | -40 to 50 Celsius (-40 to 122 Fahrenheit) |
| Function | NC (Normally Closed) |
| Refrigerant Compatibility | R404A, R134a, R407C, R507, etc. |
| Weight | 1.1 kg |
| Shipping Weight | 1.5 kg |
How does PWM control improve energy efficiency?
By using Pulse Width Modulation, the AKV 20-4 maintains a constant, high refrigerant velocity whenever it is open. This optimizes the heat transfer coefficient within the evaporator and ensures better oil return to the compressor compared to traditional mechanical valves that may throttle flow too low during low-load periods.
Does this valve provide a complete shut-off during power failure?
Yes. The 042H2028 is a Normally Closed (NC) valve. In the event of a power loss or when the controller reaches the setpoint, the valve closes hermetically, acting as a solenoid valve to prevent refrigerant migration.
Can this valve be used with CO2 (R744)?
The standard AKV 20 series is primarily designed for HFC/HCFC. For high-pressure CO2 applications, it is recommended to check the specific pressure ratings or look into the AKVH series, as R744 systems often exceed the 28 bar PS rating of this model.
Filtration Best Practices: To ensure the longevity of the 13.5 mm actuator and the internal seat, a high-quality filter drier (such as Danfoss DML) must be installed upstream. Because the valve cycles rapidly, any solid debris in the liquid line can cause abrasive wear or prevent the valve from closing fully.
Brazing & Thermal Safety: During the soldering of the inlet and outlet connections, it is mandatory to wrap the valve body in a wet cloth. The internal temperature must be kept below 100 Celsius to prevent damage to the precision-engineered seals and the actuator housing.
Electrical Installation: The solenoid coil (sold separately) must match the controller's voltage (AC or DC). Ensure the coil is mounted with the cable entry facing downward to create a "drip loop," preventing condensation from traveling into the electrical actuator interface.
Global Express Shipping
Returns & Warranty
Manufacturer: Danfoss
Product No.: 042H2028
Country of origin:United States
Product Type: Electric Expansion Valve
Payment: T/T, Western Union
Weight: 1500g
Shipping port: Xiamen
Warranty: 12 months
The AKV 20-4 (042H2028) is a high-performance, electronically operated expansion valve designed for precise refrigerant injection in commercial and industrial refrigeration systems. Operating on a Pulse Width Modulation (PWM) principle, the Danfoss 042H2028 (042H2028) serves a dual purpose: it acts as both an expansion device and a liquid line solenoid valve. This integration is vital for B2B applications such as large-scale supermarket refrigeration, cold storage, and process cooling, where tight superheat (SH) control is required to maximize evaporator efficiency and protect the compressor from liquid slugging. The "Type 4" designation identifies this as a high-capacity unit within the AKV 20 series.
The AKV 20-4 utilizes a specialized 13.5 mm actuator system, engineered to interface seamlessly with Danfoss ADAP-KOOL controllers. Unlike traditional modulating valves that change needle depth, the 042H2028 cycles fully open and fully closed at specific intervals; the flow rate is precisely managed by the duration of the "open" time. This design results in a robust, hermetic valve with fewer moving parts, capable of millions of cycles. Rated for a Maximum Working Pressure (PS) of 28 bar (406 psig), it is compatible with a broad range of fluorinated refrigerants (HFC/HCFC), ensuring versatility across modern cooling infrastructures.
| Feature | Specification |
| Model | AKV 20-4 (042H2028) |
| Brand | Danfoss |
| Product Type | Electric Expansion Valve (PWM) |
| Actuator System | 13.5 mm |
| Max Working Pressure (PS) | 28 bar (406 psig) |
| Max Test Pressure | 42 bar |
| Ambient Temp Range | -40 to 50 Celsius (-40 to 122 Fahrenheit) |
| Function | NC (Normally Closed) |
| Refrigerant Compatibility | R404A, R134a, R407C, R507, etc. |
| Weight | 1.1 kg |
| Shipping Weight | 1.5 kg |
How does PWM control improve energy efficiency?
By using Pulse Width Modulation, the AKV 20-4 maintains a constant, high refrigerant velocity whenever it is open. This optimizes the heat transfer coefficient within the evaporator and ensures better oil return to the compressor compared to traditional mechanical valves that may throttle flow too low during low-load periods.
Does this valve provide a complete shut-off during power failure?
Yes. The 042H2028 is a Normally Closed (NC) valve. In the event of a power loss or when the controller reaches the setpoint, the valve closes hermetically, acting as a solenoid valve to prevent refrigerant migration.
Can this valve be used with CO2 (R744)?
The standard AKV 20 series is primarily designed for HFC/HCFC. For high-pressure CO2 applications, it is recommended to check the specific pressure ratings or look into the AKVH series, as R744 systems often exceed the 28 bar PS rating of this model.
Filtration Best Practices: To ensure the longevity of the 13.5 mm actuator and the internal seat, a high-quality filter drier (such as Danfoss DML) must be installed upstream. Because the valve cycles rapidly, any solid debris in the liquid line can cause abrasive wear or prevent the valve from closing fully.
Brazing & Thermal Safety: During the soldering of the inlet and outlet connections, it is mandatory to wrap the valve body in a wet cloth. The internal temperature must be kept below 100 Celsius to prevent damage to the precision-engineered seals and the actuator housing.
Electrical Installation: The solenoid coil (sold separately) must match the controller's voltage (AC or DC). Ensure the coil is mounted with the cable entry facing downward to create a "drip loop," preventing condensation from traveling into the electrical actuator interface.
Global Express Shipping
Returns & Warranty
Orders are processed and delivered Monday-Friday (excluding public holidays).
For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .
| Country of origin |
United States
|
| Power source |
AC-powered
|
A practical engineering guide to PLC CPU operation, from deterministic scan cycles and I/O image tables to memory, communications, diagnostics, redundancy, processor sizing, and reliable system...
Sostituire un 1756-L73 non significa automaticamente aggiornare il firmware. Questa guida confronta le versioni 19.013, 21.011 e 31.011, concentrandosi sulla compatibilità dei progetti, sulle...
Implementa un circuito luminoso XOR con 3 interruttori SPST in LogixPro o RSLogix 500 utilizzando un bit di relè interno. Include tabelle della verità, equazioni booleane e verifica.
Integra Allen-Bradley CompactLogix, Caterpillar ATS e generatori nel DCS DeltaV tramite Modbus RTU. Include i gateway ProSoft MVI69-MCM e Miille DIN266.
L’istruzione ONS si attiva, ma la bobina OTE non rimane mai eccitata in Studio 5000 perché il one-shot è vero solo per una scansione. Usa OTL/OTU oppure una logica di autoritenuta.
Configura i servoazionamenti Allen-Bradley Kinetix 5500 su EtherNet/IP. Include CIP Sync, la temporizzazione IEEE 1588 V2, la selezione degli switch Stratix, la topologia DLR e l’HMI.
