Civil air defense is the only reliable method to prevent and stop theft crimes. Physical defense is one of the most widely used basic protective measures. The technical defense is a more concealed and reliable preventive measure that can detect intrusion immediately, replace personnel guarding, and will not be fatigued or sluggish for a long time. Students should pay attention to the following points in school and home anti-theft work: ①Close the windows and lock the doors at any time, and don't be afraid of trouble. Students must develop the habit of turning off lights, closing windows, and locking doors to prevent theft of criminals. ② Don't stay with people who don't know details. You can't just talk about loyalty, feelings, not principles. If you lead a wolf into the room and you will regret it, this lesson is painful. ③People who find suspicious signs should be more vigilant and pay more attention. When committing a crime, the offender often finds various excuses, such as who to look for or what merchandise to sell. Seeing that we are lax, free to enter and exit, and the door is wide open, we walk back and forth, spy on the look, wait for opportunities, find out the situation After glancing at the opportunity, he pried the door and twisted the door to stolen. When encountering such suspicious personnel, students should take the initiative to ask, if the person who comes has a valid reason, they can generally make it clear. If the person who comes ca n’t tell the right reasons and has more doubts, and his face is bound to panic, he needs further cross-examination. If necessary, he can also ask him to show his ID, student ID, work permit and other identifications. If it is found that the person carrying evidence may be a tool for committing crimes or stolen goods, one can send someone to talk with him to delay the time, and on the other hand call the school security department or public security organ to investigate the person as soon as possible. ④Students should actively participate in the safety duty of classrooms and dormitories, and assist the school security department to do safety precautions. By participating in security precautions such as duty and patrol, not only can you protect yourself and others ’property, but you can also increase your awareness of security and theft, and train and grow your talents for social practice. ⑤ Pay attention to keeping your own keys, including all kinds of keys in classrooms, dormitories, bags, drawers, etc., and you cannot lend it to others or throw it around in order to prevent "unexpected guests" from copying or waiting for theft. Gate Valves are called "full-flow" valves; there's a direct unobstructed path for flow right through the middle of the valve. A wedge-shaped brass gate is lowered into a machined slot to close the valve. They should either be completely open or completely closed. Water flowing through a partially open gate valve wears away the metal and causes the valve to fail over time. Brass Gate Valve, Flanged Gate Valve, High Pressure Gate Valves, Water Gate Valves ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsir-valve.com