How to solve the problem of pressure thermometers failing due to environmental conditions

Environmental Factors Leading to Pressure Thermometer Failure

Pressure thermometers are widely used in refrigeration systems, HVAC equipment, and industrial fluid applications. Their measurement accuracy and service life are highly influenced by the operating environment. High temperature, low temperature, humidity, corrosive media, vibration, and pressure fluctuation can all contribute to performance degradation or complete instrument failure. Understanding how environmental conditions affect pressure thermometers is essential for ensuring long-term reliability.

High-Temperature Conditions and Failure Prevention

Extended exposure to high temperatures can negatively affect elastic elements, sealing materials, and internal transmission mechanisms within pressure thermometers. Bourdon tubes, diaphragms, and capillary components may experience reduced elasticity, material fatigue, or permanent deformation under thermal stress.

High-temperature environments require pressure thermometers constructed with heat-resistant materials such as stainless steel elastic elements and high-temperature filling fluids. Thermal isolation components or cooling loops can reduce direct heat transfer. Installation locations should avoid proximity to heat sources and radiant thermal exposure.

Low-Temperature Environments and Performance Stability

Low-temperature conditions may cause sluggish response, pointer lag, or mechanical damage due to increased viscosity of internal filling fluids and reduced material flexibility. Extreme cold may also lead to seal contraction and potential leakage.

Low-temperature-rated pressure thermometers with specialized low-viscosity filling fluids should be selected. External insulation or trace heating can maintain acceptable operating temperatures. Installation designs should prevent ice formation and freezing condensation around the instrument housing and process connection.

High Humidity and Condensation-Related Failures

High-humidity environments increase the risk of moisture ingress, leading to internal condensation. Moisture accumulation can cause pointer sticking, scale corrosion, and visibility degradation. Repeated temperature cycling accelerates condensation formation inside the instrument.

Pressure thermometers with high ingress protection ratings and fully sealed housings are recommended. Moisture-resistant internal filling and corrosion-resistant components help prevent humidity-related failures. Proper sealing at connection points is critical to block water penetration through piping interfaces.

Corrosive Media Exposure and Material Protection

In chemical processing, refrigeration, and industrial systems, pressure thermometers may be exposed to corrosive fluids or contaminated refrigerants. Chemical attack on wetted parts can cause pitting, cracking, and loss of mechanical integrity.

Material compatibility must be evaluated during instrument selection. Stainless steel alloys, special coatings, or corrosion-resistant diaphragm seals provide effective protection. Diaphragm isolation assemblies prevent direct contact between aggressive media and internal measuring elements.

Vibration and Mechanical Shock Mitigation

Pressure thermometers installed near compressors, pumps, or rotating equipment are subject to continuous vibration and mechanical shock. Excessive vibration accelerates wear of internal gears and linkages, resulting in unstable readings or structural damage.

Vibration control measures include flexible mounting, vibration-damping brackets, and capillary extensions. Liquid-filled pressure thermometers reduce pointer oscillation and improve readability. Rigid pipe mounting should be avoided in high-vibration zones.

Pressure Fluctuation and Overload Protection

Frequent pressure pulsation and sudden pressure spikes impose cyclic stress on elastic components. Operating beyond rated pressure limits can lead to permanent deformation or catastrophic failure.

Proper range selection ensures normal operating pressure remains within the recommended portion of the scale. Snubbers, dampers, and pressure restrictors help reduce dynamic pressure impact. Overpressure protection devices safeguard the instrument from transient pressure events.

Installation Environment and Mechanical Stress Control

Improper installation significantly contributes to premature failure. Misalignment, excessive tightening torque, or unsupported piping can introduce mechanical stress that compromises instrument integrity.

Pressure thermometers should be installed in the recommended orientation. Mechanical loads from piping must be minimized through proper support. Thermal expansion stress should be isolated from the instrument body to maintain long-term accuracy.

Routine Inspection and Environmental Maintenance

Harsh environments demand regular inspection and maintenance. Periodic calibration verification, housing integrity checks, and seal inspections help detect early signs of environmental degradation.

Maintenance intervals should align with environmental severity. Proactive monitoring improves measurement reliability and reduces unexpected downtime. Environmental maintenance practices directly extend service life.