Why Solenoid Valves Are Used in Refrigeration Systems
Refrigeration systems are found everywhere—from industrial cold rooms and heat pumps to commercial freezers and HVAC chillers. A well-designed refrigeration loop must precisely control the flow of refrigerant, manage pressure drops, and respond quickly to changes in demand. That’s exactly why solenoid valve is used in refrigeration system: it provides fast, reliable, and electrically controlled on/off switching of refrigerant flow, helping ensure system stability, safety, and efficiency.
In this article, we’ll explain in detail why a solenoid valve is used in a refrigeration system, what roles it performs, key selection considerations, and then spotlight three ASCO solenoid valve series (via Actuation) that are especially well suited to refrigeration environments.
Why a Solenoid Valve Is Used in Refrigeration System: Key Functions
To understand why solenoid valve is used in refrigeration system, let’s break down the roles it plays:
On/Off Control of Refrigerant Flow
A solenoid valve allows the system to rapidly open or close a refrigerant line (liquid or gas). During start/stop cycles, the solenoid valve can block refrigerant flow entirely, enabling defrosting, isolation, or staging of capacity.
Interlock & Safety Functions
In many refrigeration setups, a solenoid valve is used as a safety device: if a system fault (e.g. overpressure, electrical fault, or compressor off) is triggered, the solenoid can cut off refrigerant flow to prevent flooding, overpressure, or backflow.
Staging & Zoning
Modern refrigeration systems often use multiple cooling circuits or zones. A solenoid valve allows switching individual circuits on/off depending on load demand. This modular switching helps improve energy efficiency—only zones that require cooling are fed refrigerant.
Defrost or Bypass Control
During defrost cycles, refrigerant or suction gas may need to be bypassed or diverted. A solenoid valve can block or reroute the flow during those intervals, enabling controlled defrost behavior.
Pressure Differential & Pilot Operation
Especially in systems with large refrigerant volumes or high pressures, pilot-operated solenoid valves are preferred because they require minimal actuation force. The valve uses system pressures and a small pilot orifice to achieve full opening or closing. Using such valves helps minimize power consumption and wear.
By combining responsiveness, isolation capability, and reliable actuation, a solenoid valve becomes indispensable in maintaining control and safety in refrigeration loops. That is precisely why solenoid valve is used in refrigeration system: to provide high-speed, dependable electrical control of refrigerant under a variety of pressures and environmental conditions.
What to Look For: Critical Specs for Refrigeration Use
Because refrigerants (e.g. R134a, R410A, ammonia, CO2) pose special challenges—pressure, chemical compatibility, temperature extremes—choosing the right solenoid valve is crucial. When selecting ASCO or other solenoid valves for refrigeration, these parameters matter:
Material compatibility: Valve body and internal seals (e.g. EPDM, FKM / Viton, PTFE) must resist refrigerant and lubricant oil attack.
Pressure rating & differential: The valve must handle the maximum system pressure plus a margin, and operate reliably even at low ΔP (pressure differences).
Pilot or direct operation: For large orifice sizes, pilot-operated valves are more practical (lower coil force needed).
Response speed: Rapid opening/closing reduces transient effects like pressure spikes or slugging.
Mounting orientation and flow direction: Ideally the valve should work in any orientation, or be mounted per manufacturer guidelines.
Leak-tightness: Internal leakage must be minimal to avoid refrigerant loss or inefficiency.
Environmental robustness: Outdoor usage may demand IP rating, corrosion resistance, or temperature extremes.
Actuation’s ASCO solenoid collection includes multiple series adaptable for general service and harsher applications.
Top 3 ASCO Solenoid Valve Series for Refrigeration / Cold Systems
Below are three ASCO series (via Actuation’s catalogues and general ASCO specs) that align well with refrigeration or similar fluid control tasks. These series are commonly stocked and versatile.
The ASCO 238 series is a general service range often stocked in the UK (as per Actuation’s ASCO catalogue).These are 2-port (2/2) valves available in normally closed or normally open configurations, with brass or stainless body options. The 238 series is suited for control of gaseous or liquid media, and offers reliable sealing and appropriate pressure ratings. The ability to configure the series with suitable elastomers makes 238 valves a good candidate in moderate refrigeration duty (e.g. lower pressures, moderate temperature).
One example product: ASCO SCE238C002
2. ASCO Series 210 / 210BM
The ASCO 210 series is a pilot-operated valve in the ASCO portfolio. It’s frequently used in HVAC and fluid control sectors for controlling gases or liquids with minimal actuation force. Because pilot-type operation helps in handling larger flows or higher pressures with smaller coils, it is often suitable to refrigeration systems with higher head pressures. The 210 series also supports various seal materials and port sizes. Actuation lists 210 among its commonly stocked series.
One real-world product: ASCO 210 solenoid valve
3. ASCO Series 256
The ASCO 256 compact series is frequently used in many industrial and commercial applications (liquid, gas, etc.). Emerson Its compact design, ability to mount in tight spaces, and availability in multiple materials makes it attractive for refrigeration systems where space or retrofitting is tight. Also, its ability to be manifolded and handle modest flows suits many cooling circuits. Because refrigeration installations often require compact, robust valves, the 256 series is a good fit for auxiliary circuits or branch lines.
One product example: ASCO G256C137S1V01FH
Example Integration in a Refrigeration System
Imagine a commercial freezer unit with multiple cooling zones. A central refrigeration compressor feeds multiple evaporator circuits. In each branch, you install a Series 256 compact ASCO solenoid valve to switch on that zone only when needed—its compactness keeps piping neat. The main feed line might use a Series 210 pilot-operated ASCO valve to cut off refrigerant flow during off cycles or defrost mode (benefiting from low coil power for large ports). For a bypass or safety cut-off on a smaller side circuit, a Series 238 valve (brass or stainless with compatible elastomer) can provide a reliable shutoff.
Because these ASCO series are well stocked via specialists like Actuation, you benefit from ready availability of parts, spares, and technical support.
By combining these valves appropriately, the system achieves fast switching, efficient zoning, safety isolation, and reliability—precisely the goals behind why solenoid valve is used in refrigeration system.
FAQs
1. What exactly is the primary reason why solenoid valve is used in refrigeration system?
The primary reason is to allow precise electrical on/off control of refrigerant flow—facilitating zoning, defrosting, safety cutoffs, and staged operations—without mechanical intervention.
2. Can any solenoid valve be used in a refrigeration system?
No. You must select a valve with compatible materials (body, seals), proper pressure ratings, low internal leakage, and adequate temperature tolerance. Standard valves not rated for refrigerants or cold environments may fail prematurely.
3. How do I choose between direct-acting and pilot-operated solenoid valves in refrigeration?
For small or low flow circuits with low pressure differential, a direct-acting valve suffices. For larger lines or higher pressures, a pilot-operated valve (like ASCO 210) is better because it uses system pressure to assist opening/closing, reducing coil load and wear.
4. Are the ASCO 238, 210, or 256 series good for low-temperature refrigerants like CO2 or ammonia?
These series, when configured with compatible materials (e.g. stainless body, PTFE or FKM seals), can be adapted to low-temperature or aggressive refrigerants. Always check the manufacturer’s datasheet to ensure compatibility with the specific refrigerant and temperature range.
5. How often should solenoid valves in a refrigeration system be maintained or checked?
Inspect solenoid valves every 6 to 12 months in typical use. Check electrical coil condition, leak tightness, cleanliness, and proper actuation. In harsh or heavily loaded systems, more frequent checks (e.g. quarterly) may be prudent.
