Home / News / Maintenance and repair of hydraulic wrench

Maintenance and repair of hydraulic wrench Posted by : admin / Posted on : Nov 12, 2021

1. In the design, according to the requirements of the bolt tensioner instructions, reserve the exposed length of the bolt (generally, the exposed length of the bolt should not be less than the nominal diameter of the bolt after the nut is tightened), and check the use space of the bolt tensioner, including The height direction of the bolt tensioner and the radial direction of the nut can meet the requirements of the Hydraulic Crimping Tools.

2. Calculate the set tension Fh of the bolt tensioner according to the required pre-tightening force F. Check that Fh should not exceed the allowable stress of the bolt, especially when the bolt length is short, because the bolt clamping part is long. The smaller the fine ratio, the larger the Fh/F0 ratio.

3. For multiple bolts distributed in a rectangle or circle on the flange surface, when a smaller number of bolt tensioners are used to stretch a larger number of bolts, the subsequent tension will affect the tension before the adjacent and similar bolts. Stretching force will affect it, so all bolts must be stretched in stages, in sequence, and multiple cycles to prevent uneven stretch between bolts. The best method is that the number of bolt tensioners is equal to the number of bolts, so that all bolts can be stretched in the shortest time, and the difference in tension between bolts is the smallest.

4.For the bolts installed through the bolt tensioner, in the later maintenance and replacement, the hydraulic tensioner must also be used for tightening.

Views: 31