The bolt heating rod is mainly an electric heater used for heating during the installation and removal of steam turbine bolts. It features reasonable structural design, high thermal efficiency, small size, light weight, few failures, and long service life. It has good mechanical performance, wear resistance, reliable and stable operation, low noise, easy disassembly and assembly, simple maintenance, strong overload capacity, impact resistance, and small inertia moment.
First, direct bimetallic strip temperature control. Simply put, a bimetallic strip is placed inside the bolt heating rod. Since the two sides of the bimetallic strip are made of different materials with different thermal expansion coefficients, this feature allows it to automatically disconnect when the set temperature is reached. The advantages are simple structure, low cost, and high reliability. The difference between regular products from legitimate manufacturers and counterfeit goods largely lies here. Counterfeit products use inferior materials, which are prone to fatigue after a period of use, causing failure to trip at the set temperature and leading to irreversible consequences. The disadvantage is that regardless of the material, bimetallic strips have an aging period, so I suggest replacing them every two years.
Second, using thermistors to detect temperature and thyristors to control the on/off of the heating rod.
1) Integrated thermistor and heating rod: The advantage is convenient installation with fewer wires and a neat appearance. The disadvantage is that because the thermistor is close to the heating rod, the internal temperature of the heating rod may reach the set temperature while the water temperature in the fish tank has not reached the set temperature. From daily use, you can see that the heating rod stops heating after a short while and then starts heating again after some time.
2) Separate thermistor and bolt heating rod: The advantage is faster heating. The thermistor and heating rod can be placed far apart, which overcomes the disadvantage of the integrated type mentioned above.
