blog about Choosing the Right Thermal Valve for Cooling Efficiency

In refrigeration system performance optimization, the thermal expansion valve plays a pivotal role. Engineers face a critical choice between internally equalized and externally equalized designs. Understanding their differences is essential for precise system selection.

Internally equalized expansion valves derive their balancing pressure from the evaporator inlet. This design is ideal for systems with minimal evaporator pressure drop. Examples include:

• Saginomiya's VPX series
• Danfoss's T2 series

Externally equalized valves obtain balancing pressure through an equalizer tube connected to the evaporator outlet. This configuration provides superior control accuracy when evaporator pressure drop is significant, as it better reflects the actual pressure at the evaporator's end. Common models include:

• Saginomiya's WPX series
• Danfoss's TE2 series

The decision primarily hinges on evaluating the evaporator's pressure drop. With substantial pressure drops, internally equalized valves may lead to inaccurate superheat control, compromising system efficiency. In such cases, externally equalized valves prove superior.

Proper expansion valve selection remains crucial for ensuring refrigeration systems operate at peak efficiency and stability. Engineers must carefully assess system requirements to determine the optimal configuration.