What additional pressure in psi must be added for each 100 ft of hose when the pumper is more than 100 feet from the fire department Siamese connection?

The requirement for adding additional pressure in psi for each 100 feet of hose when the pumper is positioned more than 100 feet from the fire department Siamese connection is based on the friction loss that occurs in the fire hose. This friction loss can be significant as the length of the hose increases.

For every 100 feet of hose, professionals in the fire service recognize a standard increase in pressure to overcome this loss. The value of 10 psi is commonly used, as it is a practical figure that has been established through experience and operational guidelines. This increase helps to ensure that sufficient water pressure reaches the nozzle, allowing for effective firefighting operations.

Therefore, adding 10 psi for every additional 100 feet of hose laid allows firefighters to compensate for the pressure lost due to friction in the hose, ensuring that they maintain the necessary flow rate and pressure at the nozzle to effectively combat a fire.