As the storage and transportation pressure vessel, spherical tank is widely used in chemical engineering, petroleum and other fields. In the process of manufacture and usage, defects such as cracks can easily appear, which will results in safety risks. In this paper, the finite element analysis is carried out on a Q370R steel spherical tank with penetrated crack by adopting ANSYS software, and the defect is evaluated by applying the general failure assessment diagram based on J-integral theory. This method can provide a reference for the safety evaluation of pressure vessels with defects.

In view of the internal leakage and inflexible switch and adjustment of the air bypass damper and flue bypass damper of the fired heater waste heat recovery system, this paper improves and perfects the drive mechanism, blade seal, and adopts the four-bar linkage parallel contact soft seal to realize near-zero internal leakage of the damper. In addition, in terms of the control mode, the sealing and regulating functions are integrated on one damper, it can accurately control the regulating blades at the opening angle and the rapid response of the sealing blades to the on-off signal, so as to meet the on site process requirements.

There are many types of burners used in tube heaters. Due to the differences in burner structure and mechanism of combustion, the formation of NO_x could be different during the combustion. For the heaters that have not been replaced with low NO_x burners in time for some reasons, if the burner is replaced by shutting down the device to meet the environmental protection emission requirements, it will affect the normal production operation. Then the burner can be revamped online, adopting low NO_x combustion mechanism to change the fuel combustion mode to reduce the flue gas NO_x content. The online revamp of the burner should consider such factors as single heat load, fuel gas properties, air supply, temperature, height of the furnace, and the distance between the furnace tube and the burner and so forth. This paper introduces this technology by taking the online revamp of a 2 Mt/a residue hydrogenation unit with low NO_x burner as an example. The data after the revamp indicates that the revamp has achieved good results.

After the establishment of the PipeChina Group, it is clearly required that welding of pipeline with steel grade of X70 and above should adopt automatic welding. Hence automatic welding of domestic longdistance pipelines has been promoted comprehensively. With the large-scale applications of internal pipeline automatic root welding technology, its technical weaknesses have gradually emerged. And the external pipeline automatic root welding technology can overcome these weaknesses. It has unique technical advantages and is worthy of in-depth research. Through the analysis and research of the automatic root welding equipment and root welding technology at home and abroad, the basic theories and key technical points of pipeline automatic root welding technology have been mastered. Through actual welding tests, it is proved that the external automatic root welding has good welding quality, high efficiency and wide scope of application. It is worthy of further promotion and use in long-distance pipeline projects.

In order to improve the product quality of 16MnDR steel low-temperature pressure vessels and prevent cold cracks during welding, this paper analyzes the selection principles of welding materials, the effects of welding heat input on welding quality, the effects of post-weld heat treatment on the elimination of residual stress and the control of welding process. Through the testing of different welding heat input energies in the process of welding process evaluation, a set of welding process parameters that can ensure the welding quality is selected. The results from non-destructive testing and physical and chemical performance tests show that the optimal welding process can ensure the welding quality of 16MnDR steel low-temperature pressure vessels. This can provide technical support for the manufacture of low-temperature pressure vessels.

There is a big dispute on whether flame arrester should be installed on the hydrogen vent pipeline of the hydrogen fueling station within the industry. This paper discusses the necessity of installing flame arresters on the hydrogen vent pipeline of the hydrogen fueling station, foreign and domestic hydrogen-related standards and the practical experience of hydrogenation fueling stations. The results show that flame arresters should not be installed on the hydrogen vent pipeline in order to ensure the safe relief of the hydrogen storage vessel and hydrogen refueling system.

Flanges can be divided into equipment flanges, pipeline flanges and nozzle flanges for equipment and pipeline connections according to the disciplines they correspond to in engineering. This paper briefly explains the design features of these three types of flanges, and introduces the preferred checking methods for equipment and piping disciplines. Different calculation results were obtained from adopting different checking methods under external load preferred by each discipline through a representative engineering example. On this basis, the paper further elaborates the calculation principles, respective characteristics, and existing problems of equivalent pressure method, NC3658.3, ASME Section Ⅷ and EN1591. Finally, combining with the comparison and analysis of the calculation results, suggestions for the selection of appropriate checking methods for smalldiameter nozzle flanges under external load are made.

There is greasy dirt flowing out of the leak detection hole of the tank foundation in a petrochemical company, and it is suspected that the bottom plate has leaked. For quick determination of the leakage area, acoustic emission detection is carried out and the initial location of the leakage area is determined through location by difference of times. After the replacement of the medium, magnetic leak detection is carried out on the bottom plate of the tank, and other non-destructive tests such as vacuum leak testing and magnetic powder inspection are carried out on the weld parts. Finally, the location of the defect causing the leakage is determined. According to the corrosion situation in the tank and combined with the results of the settlement detection, the cause of the leak is confirmed to be the corrosion perforation of the tank bottom plate due to the action of deposited water under the condition of rigid inclination of the foundation. The maintenance and follow-up recommendations for operation are presented according to the results of the above analysis.

The temperature fluctuation of the support bearing bush of the ethylene refrigeration compressor of a domestic 1000 KTA ethylene plant project has affected the safety and stability of the production of the plant. Combining with the operation status monitoring, lubricating oil detection, and bearing bush structure, this paper analyzes the causes of the temperature fluctuation fault of the bearing bush. And it is found that the oxidation of the lubricating oil and the formation of paint film are the direct causes of the temperature fluctuation of the bearing bush in compressor, and structural factors such as the lower limit of the bearing bush installation clearance and the small diameter of the oil inlet hole lead to higher temperature of the bearing bush, which accelerates the oxidation process of the lubricant oil and occurrence of paint film. Through online replacement of lubricating oil and installation of pneumatic oil filter for paint film, the problem of temperature fluctuation of the bearing bush in ethylene refrigeration compressor has been solved effectively, and no temperature alarm has occurred, which meets the requirements for safe and stable production of ethylene plants.

During the operation of the cracking compressor of an ethylene plant with an annual output of 1.1 million tons, the output power of the turbine has been continuously decreased and the load of the plant has been severely limited. In this paper, the causes of the power reduction of the turbine are analyzed. The comprehensive technical scheme of on-line cleaning agent filling and saturated steam cleaning is adopted for the large-scale twin-cylinder turbine unit and the turbine power of the cracking compressor is restored completely. This technical scheme is the first application in the industry and can provide a reference for on-line treatment of turbine power decrease in large-scale units.

Steam turbine unit is the key equipment in refinery enterprises which plays an important role in the process of production. The static test is the final test in safety guarantee before the start-up of the steam turbine unit, and the establishment of the quick closing oil pressure is the key to the smooth progress of the static test. This paper analyzes the oil circuit diagram of quick closing components of some equipment in certain company. Combining with the related problems encountered in the practical management of equipment over the past few years, it puts forward solutions to the problems, and summarizes the solutions to some typical problems systematically, which is helpful to promote the improvement of equipment management.

Gasoline adsorption desulfurization technology has the advantages of high desulfurization ratio, low hydrogen consumption, low energy consumption, low octane loss, high gasoline yield, and plays an increasingly important role in the refining process. Based on the problems exposed in the overhaul of reactor in gasoline adsorption desulfurization unit (hereinafter referred to as S Zorb unit), this paper analyzes the reasons for the abrasion of reactor distribution panel and the blockage of bubble cap combining with the operation experience of S Zorb unit. Then it puts forward a variety of solutions from the three aspects of design, process and overhaul, which can provide reference for the handling of related problems.

According to the characteristics of equipment management in petrochemical enterprises, this paper designs the architecture and functions of prognostics and health management system with edge layer, IaaS layer, PaaS layer and SaaS layer, which is based on the Open System Architecture for Condition Based Maintenance (OSA-CBM) and the architecture of industrial Internet platform, combined with industry Internet of things, intelligent fault diagnosis, big data analysis and other technologies. The system provides services to end users in the form of industrial kits and expert services. The results of the system have been applied to many large petrochemical enterprises, achieved good application results, reduced enterprise operation costs and promoted the reform of enterprise equipment management.

There are many leakage points and disorderly volatilization of the medium in pontoon floating ceiling, which not only causes huge economic losses, but also brings serious potential safety hazards and environmental pollution problems. According to the Guidelines for the investigation of VOCs Pollution Sources in Petrochemical Industry and the related attachments issued by the General Office of the Ministry of Ecology and Environment, this paper estimates the edge sealing loss, floating ceiling accessory loss, floating ceiling joint loss and hanging wall loss by formula method. It puts forward the improvement measures for pontoon floating ceiling. According to the test data after putting into use, it is proved that the measures are effective.