Armored thermocouples are widely used in core temperature measurement links such as industrial boiler operation, pipeline wall temperature detection and thermal system monitoring in global thermal power, chemical and petroleum engineering. The installation standard of thermocouples directly determines the accuracy of temperature measurement data and the long-term stable operation of equipment. Irregular installation is the main cause of sensor failure, data deviation and shortened service life in overseas engineering projects. Summarizing a complete set of standardized installation specifications suitable for foreign trade engineering scenarios can effectively guide overseas construction teams to operate correctly, reduce after-sales faults and improve project acceptance qualification rate.
The installation height and fixing process of thermocouple pressure blocks are the basic guarantee of standardized construction. The pressure block installation height must be unified and standardized, usually controlled at 150mm to 200mm above the pipeline or equipment layer surface. Unified height setting ensures uniform stress of each measuring point, consistent heat conduction conditions and no systematic deviation of temperature data. In terms of welding technology, three-sided spot welding is adopted for pressure block fixing, but spot welding is strictly prohibited at the thermocouple insertion port to avoid welding high-temperature damage to the sensor body. Meanwhile, side spot welding construction must avoid welding the fixing screws to death, ensuring convenient later disassembly, maintenance and replacement, which is particularly important for overseas equipment daily maintenance.
For pipeline wall temperature measurement projects, symmetrical installation specifications must be strictly implemented. Armored thermocouples for pipeline wall temperature detection need to be installed symmetrically up and down to collect multi-point temperature data, avoid single-point measurement error caused by uneven pipeline heating, and ensure comprehensive and accurate monitoring of pipeline wall temperature. During installation, the thermocouple must be fully inserted in place, and the fixing screws must be tightened firmly to prevent sensor displacement and loose contact caused by equipment vibration and medium flow impact, avoiding data fluctuation and signal interruption faults.
Standardized protection and wiring specifications are essential for long-term stable operation of overseas equipment. The lead-out part of armored thermocouples is recommended to be equipped with small groove boxes for protection, and stainless steel wires are used for fixed binding instead of ordinary iron wires to prevent rust and corrosion in high-temperature and high-humidity industrial environments, ensuring firm and durable fixing. The interface between the thermocouple and the furnace wall must be wrapped and sealed tightly, and then led out through a self-made protective pipe to isolate external dust, high-temperature gas and corrosive media, protecting the internal sensor structure from damage.
Aiming at the structural characteristics of boiler equipment, targeted anti-settlement and heat insulation protection measures need to be taken. Boiler operation will produce settlement deformation after long-term operation, so a transition junction box must be installed at the thermocouple lead-out end, and then connected to the preamplifier through compensation wires to avoid wire breakage and signal disconnection caused by equipment settlement and displacement. In addition, the bridge frame and protective pipe between the furnace wall and the preamplifier cannot be fully enclosed. A heat dissipation gap must be reserved to prevent high-temperature heat flow from directly impacting the preamplifier, causing internal component burnout and equipment damage. Many overseas engineering equipment failures are caused by ignoring this detail, resulting in unnecessary project losses.
Finally, the installation position and wiring quality must be strictly controlled. The preamplifier installation position should not be too far, matching the effective length of the thermocouple to avoid insufficient wire length and unable to install. All wiring operations must ensure correct circuit sequence and firm and reliable connection, preventing signal disorder and open-circuit faults caused by virtual connection. Standardized full-process installation specifications effectively ensure the measurement accuracy and service life of armored thermocouples, providing reliable technical standards for foreign trade engineering construction and equipment supporting.
