Tong Lige from Tsinghua University and Bai Shiwu and Liu Fangneng from China Petroleum Pipeline Research Institute established a BP neural network model to predict the crack tip opening displacement (CTOD), the performance parameters of high-strength pipeline steel (X70) welding joints, to provide an effective means for optimizing welding process parameters.

Do you know the difference between pneumatic butterfly valve and flexible metal sleeve
Flexible metal sleeve refers to PULLKA wire maintenance tube. The standard tube is rolled from galvanized steel strip, steel strip and electrical paper. In addition, there are PVC coating, aluminum coating and stainless steel coating sleeves specially made for outdoor use, high temperature, cold and clean or corrosive gas environment.
Flexible metal casing has excellent corrosion resistance, good vibration resistance, light weight (only 14 times the weight of steel pipe), and unlimited length. It can be cut according to engineering requirements and embedded in the reinforcement mesh. The outer surface of the pipe is threaded and can be followed and bent with corresponding accessories. It is mainly used for embedding in concrete and maintenance of outdoor low-voltage electrical wiring, and can also replace the traditional pneumatic butterfly valve as the wire maintenance pipe between steel pipe and electrical equipment.
Pneumatic butterfly valve: The pneumatic butterfly valve used in electrical engineering refers to the unfilled pneumatic butterfly valve made of galvanized low-carbon steel strip (plastic coated in recent years). The structure can be divided into single button and double button, commonly known as snake skin pipe, such as the common P3 galvanized pneumatic butterfly valve.
Pneumatic butterfly valve is generally used for electric equipment, junction box of electric actuator and cable maintenance at the tail of the end of steel pipe to protect the wire or cable from mechanical damage; It is also commonly used for the tail maintenance tube when the exposed piping has elastic (settlement) joints. Norms are listed by length of each piece according to its inner diameter.