 Flexible suction hose, also known as a suction hose, is a specific type of rigid fire hose used in drafting operations.When using this technique, the fire engine draws water for fire fighting from an unpressurized supply, such as a portable water tank, pool, or other static water source, instead of drawing water from a pressurized water supply, such as a fire hydrant.Under complete vacuum conditions, a pump would lift water , however pumps on fire apparatus are not capable of producing a perfect/ total vacuum.