What is the delivery pressure range commonly found in firefighting systems?

In firefighting systems, the commonly accepted delivery pressure range is typically between 100 and 125 PSI. This range is considered optimal for effective operation of fire hydrants, fire pumps, and standpipes, ensuring that adequate water pressure is available for firefighting efforts. Pressures lower than this range may not provide sufficient flow rates to combat fires effectively, while pressures above this range could cause damage to the system components or may exceed the operational limits of hoses and nozzles being used.

Maintaining a delivery pressure within this range ensures that the firefighting equipment functions properly and that responders have reliable and effective water supply during emergencies. Hence, this range is widely used as a standard in the design and operation of firefighting systems, making it the correct answer in this context.