The structural features of series pneumatic ball valves are:
Pneumatic actuator: new series GT pneumatic actuator, double acting and single acting (spring return), rack and pinion drive, safe and reliable; Large diameter valves are driven by a series of HAW pneumatic actuators, with reasonable structure, large output torque, double acting and single acting (spring return); Refer to our pneumatic actuator sample.

High temperature pipeline's request for compensator Understand the application failure of compensator
The compensator has a wide range of applications, from the demand for lateral displacement compensation of ordinary water supply pipeline to the demand for high temperature of flue gas and air duct in the power plant steel plant. In addition to the changeable appearance to meet the needs of the environment, its material also changes from rubber to steel and then to stainless steel with the demand for different media.
High temperature pipes are usually located in the boiler or ventilation part of the factory. As the pipes expand with heat and shrink with the influence of high temperature and ultra-high temperature, expansion joint compensators must be used to compensate the horizontal and longitudinal displacement of the pipes. When the medium exceeds 400 ℃, the compensator should pay special attention to the material when it is installed, and should not mix fish with pearls. The consumer should be strictly requested to consume according to the technical request. Because the high temperature is easy to make the corrugated compensator of asymmetric material break, explode and other phenomena, resulting in accidents and unimaginable results.
The manufacturer shall also conduct more than three high temperature leak free tests before leaving the factory, and make material analysis and inspection reports before leaving the factory.
The use of the compensator determines that it must have certain strength, greater flexibility and higher fatigue resistance, so the bellows can only be designed with thin wall and multi-layer structures. The bellows operating under working conditions is a typical low cycle and high stress component, and the parts of its wave crest and wave trough have entered into plasticity. As the bellows is a thin-walled flexible element, working under high stress conditions, it is the thinnest part of the pipeline system, so the safety and reliability of non-metallic compensators have become the most concerned problem.
The failure of non-metallic compensator during operation is mainly manifested as instability deformation and corrosion leakage, of which corrosion failure is the most.
There are two types of contraction joint corrosion: pitting corrosion and stress corrosion cracking. The necessary condition for stress corrosion is the existence of corrosive environment and internal stress. The existence of stress is one of the necessary conditions leading to stress corrosion cracking. The main sources of stress are: deformation stress and residual stress generated during the processing and forming of bellows; Working stress during the decommissioning period; The assembly stress caused by improper assembly is too large, and the wedging stress caused by corrosion products.
The flue gas energy recovery system is prone to chloride ion corrosion under low temperature conditions and sulfide corrosion under high temperature conditions. The selected non-metallic compensator data should be able to contain the corrosion caused by operation under high temperature conditions; In addition, one should prevent the generation of corrosive environment, such as cold wall during design; After installation shutdown and before cooling down, quickly replace the flue gas medium left in the pipeline and compensator to eliminate the condensation phenomenon and the accumulation of corrosive medium in the corrugated elements, adhere to the dryness and ventilation of the pipeline, and if necessary, use forced ventilation to eliminate the conditions for the formation and expansion of pitting corrosion; Under operating conditions, external insulation and other methods are used to eliminate the environment below the dew point temperature of the working medium; The second is to eliminate the internal stress of bellows as much as possible, for example, use solid solution to eliminate the deformation stress and residual stress generated during the processing and forming of bellows, and prevent the generation of constraint stress during the assembly of non-metallic compensator.