The value of tightening torque is relative not only to the nominal diameter and quality class of the bolt, but also to the security of the threaded fastener.

指出螺栓联接的扭紧力矩值不仅与螺栓的公称直径及性能等级有关，还与能否保证联接可靠工作有关。

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Girth flange bolting shall be of stud bolt type, threaded full length, and at least M16 for flange of 600 mm and smaller inside diameter and at least M20 for over 600 mm inside diameter flange.

翼缘法兰螺栓应为双头螺栓，螺纹为全长型，内径600 mm或以下的法兰的螺栓至少为m 16，内径600 mm以上的法兰的螺栓至少为m 20。

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