Minnesota Special Engineer Boiler License Practice Exam 2025 - Free Boiler License Practice Questions and Study Guide

The term that describes resistance to flow in a steam system is hydraulic friction. Hydraulic friction refers to the resistance encountered by fluid flow due to the interactions between the fluid and the surfaces of the piping system. This includes factors such as the roughness of the pipe's interior surface, changes in diameter, bends, and other fittings that disrupt the smooth flow of steam.

When steam moves through pipes and fittings, it experiences friction that can result in a drop in pressure as energy is lost to overcoming this resistance. Understanding hydraulic friction is crucial in designing and maintaining efficient steam systems to ensure that pressure drops are minimized and system performance is optimized.

In contrast, steam pressure drop specifically refers to the decrease in steam pressure due to various factors including friction but does not encompass the concept of resistance to flow as comprehensively as hydraulic friction does. Thermal expansion is related to the change in volume of water or steam as it heats up, which does not directly describe resistance to flow, and flow velocity pertains to the speed at which the steam moves through the system rather than resistance itself.