Page 3 of Technical Articles for Pipe Fitting

Formulating the construction plan 1. Principles of welding carbon steel 20 and stainless steel 304 dissimilar steel According to the analysis of the weldability of austenitic stainless steel 304 and ferritic carbon steel 20 dissimilar steel, hot cracks easily happen when the two are welded, and the...

Abstract: When a chemical plant is overhauled, two sets of overlapping fixed tube sheet heat exchangers are replaced. The carbon steel flanges at the inlet and outlet of the tube box are of different materials and specifications than the external stainless steel pipelines. In order to ensure that the...

For the selection and evaluation of materials used in equipment designed and manufactured according to the elastic design criteria, the materials that have been evaluated in accordance with ISO 15156-2 (GB/T20972.2) and ISO15156-3 (GB/T20972.3) or NACE MR0175-2003 standards can be used. The environmental...

Generally, there are three main leakages for fluids at the sealing port, including leakages at the interface, leakages caused by penetration, and leakages caused by a blow-out, as shown in Figure 1. The leakage at the interface is the leakage along the gap between...

1.4 The microstructure analysis Take another batch of the qualified tees with the same specification to compare with the cracked tees, and the sampling positions are the positions perpendicular to the main pipe axis and close to the root of the branch pipe. Figures 4a and 4b are the metallographic...

Abstract: The stainless steel TP304 tee used in the denitration facility of the power plant cracks. Through the composition analysis, the macroscopic and microscopic analysis of the fracture, the microstructure observation and the hardness test, combined with the production...

Abstract: The S31254 180° R=1D sharp turning elbow used in the high-temperature pyrolysis furnace of a company in the United States is currently manufactured by the casting process, and the steel pipe's manufacturing process is now used as the research object. The research...

Abstract: Since April 2016, there have been frequent leaks and fires at the connecting part between the flange and reducer of the cracking furnace quench boiler in 220 kt/a ethylene unit of China National Petroleum Dushanzi Petrochemical. Through various inspections and analyses, it is...

Introduction There are 8 cracking furnaces in a workshop, from NO.1 to NO.8. Furnaces from NO.1 to NO.7 are a USC-176C tube cracking furnace, and NO.8 furnace is a USC-12M circulating gas cracking furnace, of which the USC-12M circulating gas cracking furnace has the structure of a...

4. Scanning electron microscopy analysis Cut the tee along the crack's propagation direction and performed scanning electron microscopy analysis. The microscopic morphology of the fracture is shown in Figure 6, and the propagation direction of the crack was from the inner wall...

Abstract: Through the macro inspection, chemical analysis, metallographic analysis and scanning electron microscopy analysis of the tee of the stainless steel pipeline at the inlet of the liquefied gas pump of a hydrocracking unit of a certain company. It is believed that the cause of the...

2.7 The analysis of the end of the crack (1) The analysis of the macroscopic fracture: it could be seen that the surface of the fracture was uneven by intercepting the sample; dendritic crystal texture was visible, and the surface was oxidized and black....