Hydraulic torque wrenches have the benefit of being lighter, significantly quieter and generally more accurate than an equivalent pneumatic impact wrench. These qualities have made the hydraulic wrench a preferred tool in many situations.
Put simply, hydraulic torque wrenches apply a set and controlled amount of torque to a lubricated fastener. The hydraulic torque wrench was invented by George Sturdevant, from Houston, Texas. Commercially, they became available in a relatively primitive form around the early 1960s.
In attaining classification as a hydraulic wrench, it must use hydraulics as the only means to create torque, it should be self ratcheting, and it should have an accurate way to measure the applied torque. Torque wrench calibration can be maintained to insure it is applying the determined amount of torque.
Generally, hydraulic wrenches can be accurate within plus or minus 3 percent. In addition to the accuracy for torque, they can maintain the repetition of accuracy across different applications and with varying sizes of bolts.
Hydraulic wrenches are available with different specifications for different applications. Some hydraulic wrenches have a low profile wrench so that they can fit into tight spots while maintaining their power and effectiveness. Some hydraulic wrenches are rated for higher power and torque and for longer lifespans. This means they are better suited for more rugged applications under higher stress. Additionally, some hydraulic wrench systems are able to run multiple wrenches from the same setup so that they can simultaneously apply pressure. This can be especially useful in situations with many flange bolts or related applications.
Regardless of the specific application, your hydraulic wrench needs to fit your working style and environment. Make sure to have measurements for bolts, torque, and the various clearances when selecting the proper hydraulic wrench for your unique situation. Also, it is important to determine if this is for various onsite applications or if you are using this in a controlled environment. While everyone has different needs for their hydraulic wrench, most can be adapted to fit into your workflow and custom torque requirements. References: www.titanti.com