When is friction loss not calculated for piping in fire protection systems?

Friction loss is not calculated for piping in fire protection systems primarily when the piping is too small to warrant the effort of computation, which aligns with the correct answer. In many cases, particularly with smaller diameter pipes or in systems experiencing very low flow rates, the friction loss becomes negligible in comparison to other factors like elevation gain or pressure requirements. Thus, it may not impact the overall performance or calculation of the system significantly.

When flow rates are extremely low or when the pipe size diminishes to such a degree that the resistance from friction is minimal, engineers often make the practical decision to omit these calculations. This allows them to allocate resources more effectively and focus on the critical aspects of the firefighting system design without getting caught up in minor details that would not materially affect the performance of the fire protection system.

Understanding the nuances of when to omit friction loss calculations helps in efficient system design and operation, ensuring that firefighters can quickly and effectively respond to emergencies without being bogged down by overly complex calculations that do not contribute to the effectiveness of their firefighting efforts.