When the steam turbine is running, it will generate a high temperature and high pressure working environment. These high-temperature environments may have negative effects on bolts, such as thermal expansion, loosening, and fracture.

The fastening bolts of high-pressure steam turbine are mostly of large size. In the maintenance of the unit, whether it is dismantling or reinstalling and fastening, most of the work needs to be carried out in a heated state to ensure reliable fastening or easy disassembly of the bolts. Bolt heaters are an indispensable tool in the maintenance of high-pressure steam turbines.

Specifically, the functions of bolt heaters include:

1. Reduce the impact of thermal expansion: In high-temperature environments, bolts will be affected by thermal expansion. Pre heating the bolt can allow it to expand appropriately at working temperature to reduce stress and deformation caused by thermal expansion, thereby improving the performance and stability of the bolt.

2. Prevention of looseness: In high-temperature environments, bolts may become loose and lead to loose or broken connections. By heating the bolts, they can achieve the pre tightening force required by the design, preventing connection failure caused by looseness.

3. Improving the fatigue life of bolts: The fatigue life of bolts may be lower in high-temperature environments. By preheating bolts, they can improve their material properties and extend their fatigue life, reducing the risk of fracture caused by fatigue.

4. Protective bolt surface coating: Some bolts in steam turbines may have special coatings or coating materials used to improve heat resistance or reduce friction. Pre heating the bolts can prevent damage to the coating due to sudden high-temperature impact, protecting the coating quality on the bolt surface.

The steam turbine large bolt electric heater is in the form of a single heating tube, with a small diameter and unlimited length. Yoyik can achieve a length of 20-2000MM according to customer requirements. Generally, there are diameters of 17mm, 19mm, 20mm, and 22mm.