What term describes the action of combining two or more hoses into a single line to improve flow rates?

The action of combining two or more hoses into a single line to improve flow rates is accurately described by the term "siamesed connection." This process allows for the combination of multiple water supply sources or hose lines, which significantly enhances the overall water flow available to a single nozzle or outlet.

In emergency situations, where high flow rates of water are necessary—for instance, when fighting a fire—a siamesed connection can be crucial. By merging hoses, fire personnel maximize the available water supply and improve pressure, leading to more effective firefighting efforts.

A wye connection, while it does split a single line into two outlets, does not serve the same purpose as siamesing, which explicitly refers to the joining of multiple hoses into a single output. Branch coupling implies connecting additional lines to an existing line, which does not cover the action of merging hoses. An attachment fitting simply refers to a fitting used to connect hoses or equipment, rather than the specific action of combining multiple lines for enhanced water delivery.