Pre-acting valve system is an automatic sprinkler system developed in recent years, which combines fire detection and alarm technology with automatic sprinkler system and plays a dual protection role for the protected object.
When there is no fire, the pipeline on the system side of the system is inflated, so the system has the characteristics of dry system and can meet the needs of automatic sprinkler under high temperature and cold conditions.
In case of fire, the temperature-sensitive and smoke-sensitive fire detectors installed in the protected area first send out fire alarm signals. After receiving the alarm signal, the fire alarm controller sends a command signal to open the deluge valve. At this time, the pipe network at the system side is filled with water, which makes the system become a wet system before the closed sprinkler is opened.
Extended data:
Key points of construction and installation
The main feed water signal butterfly valve, deluge valve and dry alarm valve of 1) system should be installed vertically in the control room near the protected area, and the temperature of the control room should not be lower than 4℃ to avoid the failure of the whole system due to the freezing of water in the low-temperature diaphragm cavity.
2) When installing, put the diaphragm valve group into the flange of the water source pipeline, and put the gasket. After tightening the flange bolts, put the gasket at the outlet of the diaphragm valve, with the same installation specifications and 90-degree elbow, and tighten the bolts. And then connected with the system pipe network. Open a hole in the straight pipe section of the upper mouth of the dry alarm valve and connect it with a 3/4 "pipe. It is connected with air maintenance components such as low-voltage switch, air compressor and electric contact pressure gauge.
3) Floor drains shall be set at the drainage places such as system drain valves, solenoid valves, manual quick-open valves, hydraulic alarms, water replenishing funnels, etc., and the discharged water shall be discharged into sewers respectively.
4) Install pressure switch, solenoid valve, signal butterfly valve lead-out wire and air maintenance equipment on deluge valve, and connect the low-voltage switch and lead-out wire of electric contact pressure gauge with the loop of fire control center respectively.
5) The hydraulic alarm bell shall be installed near deluge valve or in public passages and duty rooms, with a pipe diameter of 20mm, an alarm pipeline length of less than 20m and a height of no more than 5m from the alarm valve.
6) After the installation, turn the deluge valve anti-reset handwheel to the anti-reset lock position, and the red dot on the handwheel is aligned with the lock position of the sign, so that the system is in a quasi-working state.
Debugging of Berry pre-action alarm valve:
(1) After all pre-acting valves are installed according to the requirements of the specification, they can be debugged and watered, so that deluge valve is in a quasi-working state. Close the lower ball valve, open the upper ball valve, supply water to the filling funnel, and start the air compressor to supply air to the system. The inflation pressure is generally within the range of 0.0 1-0.03MPa, and the inflation amount is not less than 0. 15m3/min.
(2) Open the solenoid valve or the manual quick-open valve to release the pressure of the diaphragm cavity. When the deluge valve is opened, the system side will be filled with water and become a wet system. At the same time, the hydraulic bell will ring and the pressure switch will send out an electrical signal. To test the water flow indicator, you can turn on the terminal water testing device, and after the water flows, push the paddle to send an action signal to the fire center.
After the test, close the solenoid valve or manual valve, rotate the anti-reset locking mechanism 90 degrees clockwise to the reset position, and then rotate the handwheel 90 degrees counterclockwise to the lock position after deluge valve is automatically reset, so that the deluge valve is in a quasi-working state.
Open the drain valve on the wet alarm valve to drain the water on the system side until there is water on the alarm panel, immediately close the drain valve to dry the system, and then start the air compressor to inflate the pipeline, so that the whole system is in a quasi-working state.
References:
Baidu encyclopedia-pre-acting valve