How does material selection affect corrosion resistance of HVAC pressure thermometers

In HVAC systems, pressure thermometers are key measuring instruments and are widely used for pressure and temperature monitoring of the system. The choice of its material is not only directly related to the service life of the instrument, but also determines the corrosion resistance of the equipment under complex working conditions. Materials with strong corrosion resistance can effectively prevent the performance degradation or even failure of the equipment due to corrosion during long-term operation, and ensure the stable and safe operation of the HVAC system.

Challenges of HVAC system environment to pressure thermometer materials
Pressure thermometers in HVAC systems are often exposed to a variety of chemical media and extreme environmental conditions. Refrigerants, lubricating oils, moisture, and various corrosive gases in air-conditioning systems will corrode instrument materials. Especially in systems containing refrigerants such as chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs), the corrosion resistance of the material is particularly important. In addition, drastic changes in temperature will also accelerate the fatigue and corrosion process of metal materials. Therefore, the selection of suitable materials is the key to ensure the long-term and reliable operation of the pressure thermometer.

Analysis of common materials and their corrosion resistance
Stainless steel materials
Stainless steel is one of the most commonly used materials in HVAC pressure thermometers, especially 304 and 316 grades of stainless steel. 304 stainless steel has good oxidation resistance and general corrosion resistance, and is suitable for most conventional refrigerant environments. 316 stainless steel has stronger resistance to chloride corrosion due to the molybdenum element, and is suitable for more harsh environments. Its excellent corrosion resistance can resist the erosion of most acids, alkalis and salts, greatly extending the service life of the pressure thermometer.
Brass material
Brass has been widely used in HVAC instruments due to its good processing performance and low cost. However, brass has poor corrosion resistance to certain refrigerants and chemical media, especially in the presence of ammonia or chlorine-containing refrigerants. It is prone to corrosion and stress corrosion cracking, which limits its application range.
Aluminum alloy material
Aluminum alloy is lightweight and has excellent thermal conductivity. Some low-end pressure thermometers use this material. The corrosion resistance of aluminum alloy is acceptable in neutral or mildly corrosive environments, but it is easily corroded in acidic or alkaline environments and is not suitable for changeable and harsh HVAC system environments.
Special alloys and surface treatments
To enhance corrosion resistance, some high-end pressure thermometers use nickel-based alloys or titanium alloys. These materials have extremely high corrosion and oxidation resistance and are suitable for extreme environments. At the same time, surface electroplating, spraying or anodizing can also significantly improve the corrosion resistance of the material and prevent oxidation and chemical erosion.

Specific impact of material selection on the corrosion resistance of HVAC pressure thermometers
Extend equipment service life
Highly corrosion-resistant materials can effectively resist the erosion of various corrosive media in the HVAC system, avoid rust and corrosive damage on the metal surface, thereby extending the service life of the pressure thermometer and reducing maintenance and replacement frequency.
Ensure measurement accuracy and stability
Corrosion can cause damage to the internal structure of the pressure thermometer, affect the normal operation of the sensor element, cause reading errors or even instrument failure. Corrosion-resistant materials ensure the structural integrity of the equipment and ensure the accuracy and stability of the data.
Reduce maintenance costs and operating risks
Equipment with insufficient corrosion resistance is prone to leakage and failure, bringing additional maintenance costs and system downtime risks. Pressure thermometers with excellent materials reduce the probability of unexpected system downtime and improve overall operating efficiency and safety.
Adapt to diverse working conditions
HVAC systems involve a variety of refrigerants and working conditions. The diversity of material selection meets the application requirements in different environments, such as chlorine-containing refrigerants, salt spray environments, high humidity, etc., ensuring the reliability of the pressure thermometer in complex working conditions.