Here we will be discussing the comparison of two methods for achieving correct fastener preload in bolted joints: bolt torquing and bolt tensioning.

Our ultimate goal in bolting is to achieve the correct fastener preload, also known as bolt load or axial load. When applied appropriately to a gasketed bolted connection, the bolt load creates clamping force on the gasket and produces a reliable, leak-free seal.

Now, let's delve into the definition of bolt torquing. Torquing is the most commonly used method to achieve fastener preload with bolted joints, wherein a clicker wrench applies torque to a bolt. This torque is usually measured in foot-pounds or Newton-meters. It produces axial load through rotational force on a nut or bolt head.

On the other hand, bolt tensioning produces axial load by pulling up on a fastener with what looks like a hydraulic load cell. To achieve the targeted bolt load, you need to know the area of the tensioner and the amount of force on the fastener, and then adjust the amount of hydraulic pressure.

When it comes to determining which method is the "best," it's a loaded question that depends on various factors such as joint criticality, joint component accessibility, available equipment, and the expertise of personnel. Torquing is typically more cost-effective, but the skill levels and training of those who use the torque tools equipment are determinants of how successful and accurate torque tightening will be.

Tensioning, on the other hand, is more precise, with typically +/- 10% accuracy. However, it is more expensive and more complicated than torquing, so proper training is essential to apply stud tensioning correctly.

In terms of accuracy, torque tools are generally considered accurate within plus or minus 30%, while tensioning is typically more precise. Nonetheless, torquing can be significantly more accurate when performed by an appropriately trained assembler, with proper lubrication and with calculations that include a proper K-factor, which is critical for understanding what applied torque value you will need. A well-trained assembler can achieve +/- 15% accuracy or better with torquing.

In conclusion, both bolt torquing and bolt tensioning are legitimate ways to seal a joint. The choice between the two methods depends on various factors and must be considered on a case-by-case basis.