(1) Standard
flanges shall be selected according to engineering design requirements and data.
(2) The diameter and length of the connecting bolts should meet the requirements of the code. After the bolts are tightened, the exposed thread buckles should be 2~3 buckles, and should not be larger than 1/2 bolt diameter.
(3) For the flange connection pad, it is necessary to pay attention to whether the rubber gasket is concentric with the pipe diameter, and should not be biased; if the flange groove is matched with the metal gasket, red Dan should be applied to ensure the sealing state. good.
(4) When using oil pressure and pneumatic tools to tighten the bolts, be careful not to exceed the specified torque.
(5) In order to avoid the bond between the washer and the thread when tightening the bolt and nut at high temperature, the anti-adhesive agent should be applied to the threaded part during operation.
(6) For high temperature valves above 300 °C, after the temperature rises, the flange connection bolts, bonnet fastening bolts, pressure seals and packing gland bolts must be tightened again.
(7) In order to prevent leakage, when installing the valve for low temperature, when tightening the bolt at atmospheric temperature, the shrinkage and moment generated by the parts with different expansion coefficients such as flanges, gaskets, bolts and nuts at low temperature must be considered.
