In addition, when replacing the internal spring fittings of the electric ball valve, attention should also be paid to the fact that the internal elasticity of this part is required to be large enough to serve the internal pressure effect of malicious customers and reduce the dynamic impact of the valve during operation. Generally, the purpose is to reduce the impact force generated during operation to ensure the internal sealing of the electric ball valve. In extreme cases, equipment cracks may occur, The media may leak during operation, which may pose a greater operational threat.

（2） The application of a good air conditioning system design in the exhaust system, its exhaust system must be very reasonable, but this is often ignored. In civil buildings, especially in high-rise buildings, the air tightness of the enclosure structure is very good, and the positive pressure value of the room can be maintained with less air volume. About 85~90% of the fresh air volume must be discharged out of the room through organized exhaust, so as to ensure the balance of air supply and exhaust, or no more fresh air volume can be sent into the room. In civil buildings, the exhaust air is generally discharged out of the room through auxiliary rooms such as toilets and butterfly valve water chambers. In addition, sometimes an exhaust system should be added to ensure the balance of air supply and exhaust. For toilet air exhaust, it is common practice to set one or two toilet ventilators in each toilet, which are interlocked with the exhaust fan on the exhaust shaft. We know that the fresh air system in high-rise buildings should operate all year round, and the corresponding exhaust system should also operate all year round. In other words, people who use the toilet can't control the opening of the toilet ventilator, so the necessity of installing toilet ventilator will disappear. Moreover, the operation of the exhaust system with a large fan and dozens of small fans is difficult to match and uneconomical. The noise of the actuator with the exhaust air volume of 400m3/h and the accessory toilet ventilator is about 40dB, which makes the toilet lose its tranquility. A large number of toilet ventilators also bring great trouble to maintenance. To solve this problem, we can cancel the toilet ventilator, add a constant air volume valve to the branch pipe on each floor of the exhaust shaft, and set an exhaust fan on the top of the shaft. Such exhaust system can ensure that the air volume of each floor is approximately equal, and the system is simple to control, reliable to operate, and the toilet can be very quiet.