As the core component of industrial temperature measurement, the installation method of explosion-proof thermistor directly affects the measurement accuracy, equipment life, and safety. Different installation methods are suitable for different working conditions and need to be selected comprehensively based on factors such as explosion-proof level, medium characteristics, and space limitations. The following is a difference analysis and scenario adaptation suggestions for mainstream installation methods:
1、 Mainstream installation methods and technological differences
Threaded fixed installation
Structural features: The thermal resistance probe is directly screwed into the equipment interface through threads, with strong sealing and easy installation.
Explosion proof design:
Explosion proof packing boxes or metal sealing rings are used at the threaded interface to prevent flammable gases/dust from entering the junction box.
Compliant with Ex d or Ex i standards, suitable for Zone 1/2 hazardous areas.
Applicable scenarios:
Temperature measurement of fixed equipment such as pipelines, reaction vessels, and storage tanks.
The medium is gas or low viscosity liquid, with no strong corrosiveness.
Advantages: Fast installation, reliable sealing, and low cost.
Limitations: It is necessary to reserve threaded interfaces, which requires high requirements for equipment modification.
Flange fixed installation
Structural features: It is connected to the equipment flange through a flange and fixed with bolts, suitable for large-diameter or high-pressure scenarios.
Explosion proof design:
The flange gasket adopts explosion-proof graphite or metal winding gasket to ensure sealing.
The junction box and flange are designed in an integrated manner, with an explosion-proof rating of Ex d IIC T6.
Applicable scenarios:
Large pipelines, steam pipelines, high-pressure reactors, and other applications that require high-strength fixation.
The medium is a high-temperature and high-pressure gas or liquid.
Advantages: high pressure resistance, high stability, suitable for high temperature and high pressure environments.
Limitations: The installation cost is high and needs to be matched with the flange specifications of the equipment.
Installation of activity card sleeve
Structural features: The probe is connected to the pipeline or equipment through a sleeve joint, which can be quickly disassembled and is suitable for frequent maintenance scenarios.
Explosion proof design:
The card sleeve joint is made of explosion-proof metal material and is equipped with a sealing ring to achieve dual protection.
The junction box is independently designed, and the explosion-proof rating is usually Ex e.
Applicable scenarios:
Scenarios such as laboratories, small equipment, or frequent replacement of probes.
The medium is a clean gas or liquid without strong vibration.
Advantages: Flexible installation, easy maintenance, and moderate cost.
Limitations: Weak voltage resistance and not suitable for high voltage environments.
Direct insertion installation
Structural features: The probe is directly inserted into the medium and fixed by springs or counterweights, suitable for open spaces or temporary measurements.
Explosion proof design:
The probe housing adopts explosion-proof coating, and the junction box is Ex i intrinsic safety type.
It needs to be used in conjunction with explosion-proof sleeves to prevent mechanical damage.
Applicable scenarios:
Open containers, atmospheric environment, or temporary temperature monitoring.
The medium is gas or low viscosity liquid, with no strong corrosiveness.
Advantages: Easy installation, no need to modify equipment.
Limitations: Poor stability and susceptibility to medium flow.
2、 Scenario adaptation suggestions
chemical industry
Recommended installation method: threaded fixation or flange fixation.
Reason: Chemical equipment usually requires long-term stable operation, and threaded/flange installation can ensure sealing and prevent combustible gas leakage.
Explosion proof grade requirement: Ex d IIC T6, suitable for explosive gas environments.
oil and gas
Recommended installation method: flange fixed or movable sleeve.
Reason: The pipeline needs to withstand high pressure, and flange installation is more reliable; For scenarios such as wellheads that require frequent maintenance, a card sleeve type can be selected.
Explosion proof grade requirement: Ex d IIB T4.
pharmaceutical industry
Recommended installation method: threaded fixation or sanitary flange.
Reason: GMP standards must be met, and threaded/sanitary flange installation should be easy to clean and avoid contamination.
Explosion proof grade requirement: Ex e IIC T5.
power industry
Recommended installation methods: flange fixation or direct insertion.
Reason: Flange fixation is required for high temperature and high pressure environments; Open scenarios such as boiler flue gas can be directly inserted.
Explosion proof grade requirement: Ex d IIC T6.
3、 Key precautions
Explosion proof level matching:
Select the corresponding explosion-proof level based on the classification of hazardous areas.
Media compatibility:
Stainless steel or Hastelloy probes should be selected for corrosive media.
High viscosity media require anti clogging design.
Installation depth and insertion length:
The insertion depth needs to reach the stable region of the medium flow rate.
Avoid probe contact with the bottom or wall of the container to prevent temperature gradient interference.
Maintenance and Calibration:
Regularly inspect the aging of seals and replace damaged parts.
Perform precision calibration every 6-12 months to ensure measurement accuracy.
summary
The installation method of explosion-proof thermistor should be flexibly selected according to the working conditions. Threaded/flange fixation is suitable for high-pressure and long-term operation scenarios; Card sleeve type is suitable for frequent maintenance scenarios; Direct insertion is suitable for open spaces. When selecting, it is necessary to strictly match the explosion-proof level and consider the compatibility of the medium and installation depth to ensure safety and accuracy.