Jiangsu Beiertek Building Technology Co., Ltd.

Single interlock preaction systems consist of preaction valves and corresponding piping, depending on the type of system activation, fire detection systems (by electrical detection or wet start sprinklers or dry start sprinklers or manual/electronic control valve openers), air compressors and automatic pneumatic maintenance devices, closed-type fire extinguishing sprinkler heads, piping networks, and water supply control valves, etc. NFPA requires that the system piping network be inflated when the number of sprinkler heads exceeds 20, and that the integrity of the system piping network (sprinkler heads, piping, piping components) be automatically monitored. The integrity of the system network (sprinkler heads, piping, piping components) is automatically monitored. The system network monitoring air pressure is automatically maintained at 10 ± 2 psi (0.69 ± 0.14 bar), and a low pressure alarm switch that monitors the gas pressure can signal an abnormal leak in the system network if the air pressure drops to 5 ± 1 psi (0.34 ± 0.07 bar).

The safety valve is factory preset to open fully at 25±2 psi (1.72±0.14 bar) and partially at 18 psi (1.24 bar).

A drop in system air pressure caused by a damaged sprinkler head or ruptured pipe will not cause the Model DV-5 rainshower valve to open; air pressure in the piping is used only to monitor system tightness. The pre-action valve will not open to fill the network until the detection system has been actuated.

The preaction valve consists of a DV-5 rainshower valve and a lift check valve. Since the check valve flap is airtight when closed, there is no need to pre-fill the flap with water. When an electrically activated preaction system is used, the electrical detection system operates to open the preaction valve diaphragm chamber drain solenoid valve, causing the preaction valve to open.

When a wet start or dry start system is used, a fast response closed sprinkler with K=80 is used as the fire detection element, and the closed sprinkler for fire extinguishing is cross-located in the protected area. When the fire as a detection element of the fast response nozzle early action, wet start by the action of the start of the nozzle discharge shower valve diaphragm cavity pressure water, dry start by the action of the start of the nozzle discharge dry start the air pressure in the pipeline network, which opens the dry start control valve to discharge diaphragm cavity pressure water, so that the pre-action valve opens to the system pipe network water injection.

Wet start or dry start system by the nozzle start system, pre-action system action after the water flow alarm pressure switch to provide a fire alarm signal, so there is no need to design the electrical fire detection system.

In general, the system designer chooses a single interlocking pre-action system of detection elements of the fire faster than the automatic extinguishing sprinkler head response rate. The system network fills at a pressure of only 0.69 bar, so there is only a short delay in filling the system piping to a wet system before the fire extinguishing sprinkler heads are activated.

The operating principle of the single interlocking preaction system provides flexible fire suppression. In the event of a fire, after the preaction valve opens to inject water into the system network and sends out a pre-alarm signal for a fire, and before the fire extinguishing sprinkler heads are activated, other alternative methods of fire suppression can be used to extinguish the early stage of the fire, if time permits. When other alternative fire extinguishing methods fail to extinguish the fire, the fire temperature causes the fire extinguishing sprinkler heads to operate, initiating a single interlocking pre-action system to extinguish the fire.

Single interlock pre-action systems are used in political and economic locations that are sensitive to water damage, such as computer rooms, warehouses for valuables, cultural artifacts, libraries, archives, hotels, convention centers, and locations where ice may form.