Which tool is essential for ensuring proper torque when tightening bolting for a flange connection?

A torque wrench is essential for ensuring proper torque when tightening bolting for a flange connection because it is specifically designed to apply a specific amount of torque to a fastener. This precision is crucial in applications where the integrity of a joint is dependent on maintaining the correct torque. Using a torque wrench helps to avoid under-tightening, which can lead to leaks, and over-tightening, which can cause damage to the flange or the bolts.

Other tools, like a ratcheting spanner or an adjustable wrench, can be useful for turning fasteners but do not provide the level of precise torque control necessary for critical applications like flange connections. A pneumatic drill is typically used for drilling or driving screws but is not suitable for controlling the torque applied to bolts. The ability to measure and set torque accurately makes the torque wrench an indispensable tool in mechanical assembly and maintenance work.