CASTEL electronic expansion valve 2028E/M10S01 – PWM for CO₂ (R744), orifice 01, connections Ø10 x Ø12 mm

CASTEL expansion valve 2028E/M10S01 is a PWM (Pulse Width Modulating) electromagnetic expansion valve from the 2028E series, designed exclusively for refrigeration installations using the subcritical refrigerant R744 (CO₂). Model M10S01 is fitted with orifice type 01 with a diameter of Ø0.5 mm – the second in the series of ten orifices (00–09) – and a nominal capacity of 2.30 kW for R744. The valve has soldered connections of Ø10 mm (inlet) and Ø12 mm (outlet).

Features, advantages and benefits

• PWM control (pulse opening and closing) → the amount of refrigerant supplied to the evaporator is regulated by the valve opening time within a cycle, and the electronic controller reacts quickly to changes in load. → more precise refrigerant dosing in CO₂ systems without complicated control arrangements.
• Interchangeable orifice 01 (Ø0.5 mm); 10 orifices are available with numbers 00–09 → the orifice can be replaced even after the valve has been soldered into the installation, using replacement kit 9150E/R63. → the capacity can be corrected without removing the valve, reducing service time.
• Design adapted to R744 – PS 80 bar, refrigerant temperature range TS from -50 to +100 °C, EPDM outlet seals → parameters selected for subcritical CO₂ systems (Group 2 according to Directive 2014/68/EU). → the valve is matched to CO₂ system requirements rather than being adapted from HFC solutions.
• Soldered ODS connections Ø10 mm (inlet) and Ø12 mm (outlet) → installation by soldering directly to copper piping. → tight connection and rapid installation without additional adapters.
• Sold without coil (S) → the coil and supply voltage can be selected to match the existing controller. → you only pay for the components you actually need.
• MinOPD 0 bar, MOPD 37 bar (9320 coil series, AC and DC), minimum operating time 1 s → the valve opens even with zero pressure differential and operates at high pressure differentials. → reliable performance across a wide range of installation operating conditions.

Technical data

Nominal capacity for R744 at: evaporation temperature -25 °C, condensation temperature 0 °C, liquid refrigerant temperature before the valve -4 °C.

Application

Valve 2028E/M10S01 is used in refrigeration systems with subcritical refrigerant R744 (CO₂), where the amount of refrigerant supplied to the evaporator is to be regulated by pulse control via an electronic controller. The orifice size is selected according to evaporator capacity, pressure differential across the valve and evaporation temperature.

Manufacturer: Castel | Product code: 2028E/M10S01 | Series: 2028E

FAQ – frequently asked questions

Which refrigerant can the CASTEL 2028E/M10S01 valve be used with?

Only with R744 (CO₂). The manufacturer states that 2028E series valves cannot be used with other refrigerants.

Is the valve supplied with a coil?

No. 2028E series valves are available in a version without a coil (suffix S). The MOPD values in the catalog are given for 9320-series coils in AC and DC versions.

What connections does the M10S01 model have?

Soldered ODS connections: inlet Ø10 mm, outlet Ø12 mm. The version with imperial connections (⅜" inlet and ½" outlet) carries the designation 3S instead of M10S in the code.

Can the orifice in valve 2028E/M10S01 be changed?

Yes. The orifices are interchangeable and can be installed even after the valve has been soldered into the system. The replacement kit for orifice 01 is part number 9150E/R63.

What is the nominal capacity of this valve?

For orifice 01 it is 2.30 kW for R744 (evaporation temperature -25 °C, condensation temperature 0 °C, liquid refrigerant temperature before the valve -4 °C). Capacity for other conditions is read from the R744 performance table in the Castel catalog.

How do I select the orifice size?

Determine the pressure drop across the valve (condensing pressure minus evaporating pressure and losses in the liquid line, distributor and evaporator), correct the evaporator capacity for subcooling and apply a margin for PWM regulation (Castel gives an example of +25%). Then choose an orifice whose capacity is equal to or slightly higher than the calculated value.

What are the maximum pressure and temperature range?

PS is 80 bar, the refrigerant temperature TS is from -50 to +100 °C, and the ambient temperature TA is from -40 to +50 °C.