Which tool is used to tighten or loosen hose couplings?

The spanner wrench is specifically designed for the purpose of tightening and loosening hose couplings, making it the ideal tool for this task. Its distinctive design features two pins or protrusions that align with the holes on the coupling, allowing the user to easily apply torque. This is crucial not only for securing the hose connections to prevent leaks but also for ensuring that they can be quickly released during emergency situations.

In addition, the spanner wrench is commonly found in firefighting equipment and is made to withstand the demands of the field. Its presence in the firefighting toolkit underscores its importance, as maintaining the integrity of hose connections is vital for effective fire suppression.

Other tools, like the hydrant wrench, box-end wrench, and open-end wrench, serve different purposes. The hydrant wrench is tailored for hydrant operations, primarily opening and closing hydrant valves. Box-end and open-end wrenches are used for various general mechanical tasks but lack the specific adaptations necessary for hose couplings. Hence, the spanner wrench stands out as the tool purpose-built for managing hose couplings effectively.