Common faults of pneumatic butterfly valve and their elimination methods
1. Before installation, confirm whether the product performance and medium flow arrow of our factory are consistent with the moving conditions, and insert and clean the inner cavity of the valve. Do not attach impurities and foreign matters on the sealing ring and butterfly plate. Do not close the butterfly plate before cleaning to avoid damaging the sealing ring.
2. It is recommended to use the special flange for butterfly valve, namely HGJ54-91 socket welding steel flange.
3. The best position for installation in the pipeline is vertical installation, but it cannot be inverted.
4. During use, the flow shall be adjusted and controlled by a worm gear box.
5. For butterfly valves with many times of opening and closing, open the worm gear case cover in about two months, check whether the grease is normal, and keep a proper amount of grease.
6. Check the connection parts to ensure the tightness of the packing and the flexible rotation of the valve rod.
7. The metal seal butterfly valve is not suitable for installation at the end of the pipeline. If it must be installed at the end of the pipeline, the outlet flange shall be equipped to prevent the seal ring from overstocking and over positioning.
8. The valve rod installation and use reaction shall be regularly checked for the valve use effect, and any fault found shall be eliminated in time.

Precautions for non-metallic contraction joint device
1. Compensator with flow direction request shall be stopped according to the request of medium flow direction arrow.
2. The pipeline of the device compensator, non-metallic contraction joint and expansion joint must be properly guided and fixed to make the compensator work, so the setting of the guide and fixed support must be strictly in accordance with the relevant technical materials of the design department. Please refer to "Corrugated Compensator Device" for setting guidelines of guide and fixed supports.
3. Before the device, the corrugated pipe and foreign matters in the pipe shall be cleaned to ensure the normal movement of the corrugated pipe.
4. Bellows for compensators, non-metallic contraction joints and expansion joints are formed with thin-walled stainless steel plates. Therefore, during transportation, lifting and welding, care should be taken not to damage the bellows due to knocking, scratching, arc striking, welding spatter and other reasons.
5. The devices of compensator, non-metallic contraction joint and expansion joint shall be stopped according to the pipeline construction drawing and the compensator device specification.
6. In order to keep the bellows in good working condition, the deformation of the compensator, including axial, transverse and change, cannot be used to adjust the position error of the pipe system.