This article will provide the simplest terms about tools to tension bolts hydraulically. We will discuss the function of the tool, its components, operations, and the design of the tool. It will also make a comparison between traditional as well as hydraulic bolt tensioners.
What are Bolt Tensioning Tools? And How do they function?
Tools for tensioning bolts hydraulically will tighten large-diameter bolts fast and effortlessly to high and precise preloads. Contrary to conventional methods, this one does not make use of torque. The forced turning of the bolt or nut, such as impact wrenches, the flogging of spanners, and hydraulic torque wrenches, are not necessary. All of these tools have one enemy in common, friction.
An annular bolt tensioner is placed between the nut and bolt that needs to be tightened. The tensioning tool for the bolts is accommodated by the jack, which is pushed up against the bolted joint and pulled up against the bolt’s end.
Since the force generated by the jack is directly applied to the bolt’s outer end, the tension that is equal to the force created by the jack is created within the bolt’s shank. When the jack applies the tension, you can rotate the nut at a low torque until it is fully tight. The tension exerted by the jack is then released, and a significant percentage, based on the bolt’s size and diameter, is held in the bolt’s shank.
Components of a Bolt Tensioning Tool
The bolt tensioning equipment consists of the following components:
The cylinder is an annular hydraulic jack. The puller and bolt pass through the middle of the cylinder. A recess is built into the bottom of the cylinder to allow the bridge. Two or three self-sealing quick-disconnect nipples are available to connect the hydraulic hoses.
The bridge is support for its cylinder over the nut, bolt, and socket. A circular groove has been created to accommodate socket retaining rings that can also hold the socket inside the bridge. Flats on both sides of the bridge allow for clearance for the adjacent nuts. An angled flat at the bridge’s rear clears a flange’s welding neck or another obstruction.
The puller is fitted with an internal thread that fits the bolt. The outside edge of the puller is designed to facilitate turning by hand. Tommy bar holes are included for tightening the bolt to its final. The puller is equipped with an edge that assists in locating within the center of the cylinder and then onto the bolt. The puller can transfer the force created through the cylinder into tension within the bolt.
The socket is placed over the hexagonal nut and inside the bridge. It has holes for Tommy bars to eliminate the need to drill holes into holes in the hexagon’s flats.
Bolt & Nut
An additional thread length should protrude from the nut to allow the tensioner to be screwed into and apply tension to the bolt. The length of the bolt is crucial. Specifics are included in the instruction manual to follow.
A high-quality bolt and nut can make the tensioning process easier and more precise. There is no need to put washers underneath the nut to use a bolt tensioner because friction isn’t a major element in this instance.
Operating a Hydraulic Bolt Tensioning Tool
It is important to ensure at least one bolt of thread over the nut that is used to engage the puller. Flexible hoses that use self-seal and quick-connect couplings join the tools for tensioning bolts to create a main hydraulic ring. The tensioning tools and ring main are pumped using an electric-driven, air-driven, and hand-pump.