1. The specific methods of valve connection are: flange, external thread, electric welding, and wafer type.
2. The basic elements of the valve: disconnect the access material, adjust the total flow, and change the inflow.
3. The main parameters of the valve are: pound class PN, nominal diameter pipe diameter DN.
4. The working pressure of the valve - the ambient temperature level indicates that the allowable non-impact pressure is different under different materials and different operating temperatures.
5. There are two key management systems for pipe flange standards: the European management system and the American system.
