Bronze Solenoid Valve for Freon — NC, Direct Acting, 1/4" and 1/2" Flare Connection

Cematic's bronze solenoid valve for freon is a direct-acting, normally closed solenoid valve specifically designed for refrigerant control. Unlike general-purpose solenoids, this model incorporates a Flare connection—the refrigeration industry standard—instead of NPT or BSP threads.

Therefore, it is the correct choice for installations where a Flare connection is the specified joint type in the refrigerant circuit.

Its normally closed configuration keeps the flow blocked when the coil is de-energized. It only opens upon receiving an electrical signal. Consequently, in the event of any electrical failure, the refrigerant flow is automatically cut off—the standard safety state in refrigeration systems.

Operating Principle — Normally Closed Freon Solenoid Valve

Without power, the solenoid valve for freon remains closed, as the spring holds the plunger on the seat. When the coil is energized, the electromagnetic field displaces the plunger and opens the passage. When de-energized, however, the spring automatically returns the plunger to the closed position.

Its direct action operates from zero pressure, so it does not require a minimum differential pressure. This makes it suitable for systems that start without pressure or in defrost cycles where pressure temporarily drops.

Flare Connection — the refrigeration standard

The Flare connection is the most commonly used joint type in refrigeration systems with copper piping. Unlike NPT thread, which seals by thread interference, the Flare seals by contact between two conical surfaces.

Therefore, it is more reliable with high-pressure refrigerants, as it does not rely on sealants that degrade with freon. Furthermore, it allows the connection to be disassembled and reassembled without risk of leaks if done correctly.

Construction Materials

The body is made of high-quality bronze, making it compatible with most common refrigerants. Bronze also offers good corrosion resistance in the presence of lubricating oils mixed with the refrigerant. The plunger is made of stainless steel, which is resistant to corrosion from the process fluid.

The seal is made of a material specifically for refrigerants, ensuring chemical compatibility with freon in continuous operation. Finally, the coil is encapsulated with IP54 protection, which is suitable for machine rooms with moderate humidity.

Technical Specifications

Voltage Selection

The 24 VDC voltage is the standard in modern electronic refrigeration controllers, making it the most common option in new installations. The 110 VAC voltage, on the other hand, is for systems with conventional electrical control where that voltage is available in the panel. Both options are also available in both diameters.

Refrigerant Compatibility

This solenoid valve for freon is compatible with the most commonly used refrigerants in commercial and industrial refrigeration. The main ones are listed below:

• R22 — classic freon that, although being phased out, is still present in existing systems under maintenance
• R134a — standard refrigerant in automotive refrigeration and, also, in commercial low-temperature applications
• R404A and R507A — most used in cold storage rooms and, likewise, in commercial supermarket display cases
• R410A — standard refrigerant in modern air conditioning systems, making it the most common in new installations

However, for natural refrigerants such as NH3 (ammonia) or CO₂ (R744) at high pressure, specific models should be consulted with the Cematic technical team, as they require different materials and working pressures.

Applications of the Freon Solenoid Valve

Commercial Refrigeration Systems

The solenoid valve for freon controls the flow of refrigerant in refrigerated display cases, cold storage rooms, and beverage dispensers. When energized, it opens the refrigerant flow to the evaporator. When de-energized, it closes automatically. Therefore, it is the standard liquid control component in direct expansion refrigeration systems.

Commercial and Industrial Air Conditioning

In air conditioning systems with electronic control, this solenoid regulates the refrigerant flow according to cooling demand. Therefore, it allows precise control of the system's capacity. Additionally, its NC closure protects the evaporator from liquid refrigerant floods during compressor shutdowns.

Defrost Cycles in Cold Storage Rooms

During defrost cycles, it is necessary to cut off the refrigerant supply to the evaporator. Consequently, this NC solenoid performs this cutoff upon receiving the signal from the defrost controller. In this way, the evaporator can heat up and eliminate accumulated ice without refrigerant continuing to flow.

Heat Recovery for Domestic Hot Water

In condenser heat recovery systems, this solenoid valve for freon controls the flow of hot refrigerant to the heat exchanger. Therefore, it regulates the energy transfer between the refrigeration cycle and the hot water circuit. Likewise, the NC closure ensures that the flow stops automatically when the recovery system is not active.

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