Rapid-Cooling Precise Temperature Control — Normally-Closed AC Expansion Valve

(High-precision expansion/flow control valve for heat & cold exchange systems)

Product Description

The Rapid-Cooling Precise Temperature Control Normally-Closed AC Expansion Valve is a high-precision refrigerant metering device engineered to improve evaporator performance, shorten system response time and stabilize superheat under dynamic load conditions. Available as either a thermostatic expansion valve (TXV) or an electrically-actuated normally-closed electronic expansion valve (EEV), the product family covers small commercial units through medium industrial refrigeration applications.

Constructed from corrosion-resistant brass/copper bodies with stainless-steel internals and precision seats, the valve accurately meters refrigerant into the evaporator to maintain the desired heat exchange rate and protect compressors from liquid return. The normally-closed EEV variant stays closed when de-energized (failsafe), opening proportionally under control signal to deliver rapid cooling when required — ideal for applications that demand tight temperature control and energy efficiency.

Designed for compatibility with common refrigerants (R134a, R404A, R410A, R32, R507A and others) and a wide pressure/temperature envelope, the valve improves system stability, reduces hunting and enables lower evaporator superheat for improved capacity and COP. Typical applications include air conditioning, commercial refrigeration, cold storage, transport refrigeration, heat pumps and industrial chillers.

Product Advantages

• Precise superheat control: maintains stable evaporator conditions and prevents liquid slugging.

• Rapid response: normally-closed electronic version opens quickly under demand for fast cooling recovery.

• Energy efficient: better modulation reduces compressor cycling and improves system COP.

• Robust materials: brass/copper body with stainless internals for long life and corrosion resistance.

• Wide refrigerant compatibility: designed to work with HFC/HFO blends and common refrigerants.

• Multiple control options: thermostatic, pulse/PWM driven EEV, or analog-controlled models available.

• Fail-safe behavior: normally-closed actuator minimizes refrigerant flow if power is lost.

• Modular sizing: multiple orifice/port sizes and actuator types for exact capacity matching.

• Low hysteresis and tight accuracy for stable temperature control in variable load systems.

• Field serviceable: replaceable seat/strainer and simple in-line installation reduce downtime.

Installation & Commissioning Instructions

Important: Installation and commissioning must be performed by qualified HVAC/R technicians following local safety and refrigerant handling regulations.

1. Pre-installation checks

   • Confirm valve model, capacity and refrigerant compatibility with system specifications.

   • Ensure piping is clean and dry; install a liquid line strainer or filter drier upstream of the valve.

2. Mounting

   • Install valve at the evaporator inlet. For TXV, mount the sensing bulb per manufacturer guidance (tight thermal contact, insulated if required). For EEV, mount actuator per orientation instructions — most models allow any orientation but check datasheet.

   • Use proper brazing technique if solder/weld ends are supplied; avoid overheating the valve body and protect internal parts (use heat sinks and purge nitrogen).

3. Connections

   • Make mechanical connections (flare, solder, threaded or welded) as specified. Torque threaded connections to recommended values; do not overtighten.

   • For electronic valves, connect control signal and power lines per wiring diagram: common control modes include PWM, 0–10V, or stepper/serial depending on actuator.

4. Evacuation & Leak Test

   • Evacuate the system to required vacuum level. Perform a pressure/leak test (N₂ or dry air) before charging refrigerant.

5. Charging & Set-up

   • Charge refrigerant to system design level. For TXV, set initial superheat per evaporator design (factory or system spec). For EEV, configure controller PID/parameters, initial setpoint and control loop (superheat or suction temperature).

   • Run the system through duty cycles and adjust valve calibration to achieve target evaporator superheat and stable operation.

6. Commissioning

   • Monitor suction pressure/temperature, evaporator outlet superheat and compressor inlet conditions. Verify no liquid return and steady superheat across expected load range.

   • Record final setpoints and controller parameters for future service.

7. Maintenance

   • Periodically inspect the strainer/filter, check for refrigerant contamination, and verify actuator wiring. Replace seals or seats if leakage develops.

Our Services

• Custom sizing & OEM options: orifice sizes, connection types, actuator types and control protocols tailored to your system.

• Factory testing: pressure, leak and functional tests before shipment; optional performance test report.

• Technical support: pre-sale selection assistance, installation guides and commissioning support by experienced HVAC/R engineers.

• Certifications & documentation: CE/ISO quality documentation available on request; material and test certificates provided for bulk orders.

• Packaging & logistics: export-grade packaging, palletization and multi-modal shipping; labeling per client requirements.

• Warranty & after-sales: 12-month limited warranty; spare parts and repair service available; extended warranty programs on request.

Product Attributes (typical / customizable)

Typical Applications

• Residential & commercial air conditioners (DX coils)

• Supermarket display cases and cold rooms

• Transport refrigeration (reefers) and mobile systems

• Heat pumps and HVAC chillers

• Industrial process cooling and machine tool cooling circuits