Blog
Types of AC Expansion Valves: A Comprehensive Guide
4 Types of AC Expansion Valves Explained
Complete Guide from 25+ Years Automotive Parts Manufacturer
Understanding Expansion Valve Varieties
As a global leader in manufacturing automobile air conditioning components with over 25 years of expertise, we at Qirun Auto understand the importance of selecting the right expansion valve for your AC system. While many people ask about the “three types” of expansion valves, there are actually four main types commonly used in HVAC&R systems.
The four primary types of expansion valves are: Thermostatic Expansion Valve (TXV), Automatic Expansion Valve (AXV), Electronic Expansion Valve (EXV), and Capillary Tube Expansion Valve. Each type has unique characteristics, advantages, and applications.
The Four Main Types of Expansion Valves
1. Thermostatic Expansion Valve (TXV)
The thermostatic expansion valve is the most common type used in automotive and residential AC systems. It operates based on temperature sensing to regulate refrigerant flow.
How it works: The TXV uses a temperature-sensitive bulb filled with refrigerant or similar fluid that expands or contracts based on the temperature at the evaporator outlet. This controls the valve opening to maintain proper superheat.
Applications: Automotive AC systems, residential and commercial HVAC systems, refrigeration units
Advantages: Precise control, efficient operation, responsive to load changes
2. Automatic Expansion Valve (AXV)
The automatic expansion valve maintains a constant pressure in the evaporator rather than responding to temperature changes.
How it works: The AXV uses a pressure-sensing diaphragm that reacts to evaporator pressure. When pressure drops, the valve opens wider; when pressure rises, it closes.
Applications: Smaller refrigeration systems, constant load applications
Advantages: Simple design, low cost, reliable operation
3. Electronic Expansion Valve (EXV)
The electronic expansion valve represents the latest technology in refrigerant flow control, using electronic sensors and controllers for precision operation.
How it works: The EXV uses a stepper motor to control valve opening, guided by electronic sensors that measure temperature and pressure. A microcontroller processes these inputs to optimize refrigerant flow.
Applications: Modern automotive AC systems, high-efficiency HVAC systems, precision refrigeration
Advantages: Extremely precise control, adaptive to changing conditions, energy efficient
4. Capillary Tube Expansion Valve
The capillary tube is the simplest type of expansion device, consisting of a long, narrow tube that creates a pressure drop through friction and acceleration.
How it works: As refrigerant is forced through the narrow capillary tube, its pressure drops significantly before entering the evaporator.
Applications: Small refrigeration units, window AC units, some automotive AC systems
Advantages: Inexpensive, no moving parts, reliable
Comparison of Expansion Valve Types
| Valve Type | Control Method | Complexity | Cost | Efficiency | Best For |
|---|---|---|---|---|---|
| Thermostatic (TXV) | Temperature-based | Medium | Medium | High | Most automotive applications |
| Automatic (AXV) | Pressure-based | Low | Low | Medium | Small refrigeration systems |
| Electronic (EXV) | Electronic sensors | High | High | Very High | Modern high-efficiency systems |
| Capillary Tube | Fixed restriction | Very Low | Very Low | Low-Medium | Small, simple systems |
Did You Know?
Approximately 70% of modern automotive AC systems use thermostatic expansion valves, while 25% use electronic expansion valves. The remaining 5% primarily use capillary tubes in basic systems.
Why Choose Qirun Auto for Your AC Components?
25+ Years of Specialization
We have dedicated over two decades to perfecting our automotive control valves and AC components, ensuring top-notch quality and reliability.
Global Shipping
We serve clients worldwide with free shipping on eligible orders, ensuring timely delivery to automotive businesses across continents.
1-Month Warranty
All our products come with a comprehensive one-month warranty, reflecting our confidence in their durability and performance.
Competitive Pricing
We offer high-quality components at competitive prices, providing excellent value without compromising on quality.
Selecting the Right Expansion Valve
Choosing the appropriate expansion valve for your application depends on several factors:
- System Type: Automotive, residential, commercial, or industrial
- Refrigerant Type: Different valves work with different refrigerants
- Capacity Requirements: The size and cooling capacity of your system
- Efficiency Needs: How important is energy efficiency for your application?
- Budget Constraints: Initial cost versus long-term operating costs
For most automotive applications, thermostatic expansion valves offer the best balance of performance, reliability, and cost. However, newer vehicles are increasingly adopting electronic expansion valves for their superior efficiency and precise control.
Contact Us for Premium Automotive Solutions
Located in the industrial hub of Foshan, China, our state-of-the-art facility is equipped to meet global demands with cutting-edge manufacturing technology and stringent quality control processes.
Get in Touch
Address: Xianan Er Shangyuan South Industrial Zone, Guicheng Street, Nanhai District, Foshan City, China
Phone: +86-13690143493
Email: a13690143493@gmail.com
Website: www.qirunauto.com | www.qrcontrolvalve.com
Request QuoteFor more information about our comprehensive range of automotive solutions, explore our products at Qirun Auto and QR Control Valve. Let us help you keep your automotive systems running smoothly with our 25+ years of expertise!