A SHZ is a device designed to detect and extinguish a fire or to bring it under control. In a fire, the sprinklers are opened by the action of heat and will scrape the space below. Sprinklers that do not heat up will remain closed. When a sprinkler opens, the pressure drops and the water supply is automatically activated.
Each fixed fire extinguishing system has a supply of extinguishing agent and a power source to transport it to the fire scene. The water supply is usually in a tank, less often connected to a water main. Energy to transport water to the systems is supplied by fire pumps, pressurized air, or hydrostatic elevation. Depending on the risks being protected, the water supply can range from single to combined with multiple pumps and tanks. Fire pumps with an electric motor must have a backup power source or a backup consisting of a pump with a diesel engine.
The water source may also power hydrants.
The SHZ system consists of a shut-off valve, a venile station with an alarm function and a pipeline that supplies water to individual sprinklers in the protected area. The type of sprinklers and the pipe dimensions shall be determined by hydraulic calculations. Depending on the environment and the risk to be protected, wet, dry, pre-flood or flood systems are designed.
Systems can be divided into separately enclosable zones, which are usually individual floors of a building. The zoning allows as much of the equipment as possible to remain in operation even in the event of shutdowns and repairs.