Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps ： the first step was the stress analysis when the spiral was formed, and then the stress...Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps ： the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed.展开更多
A new effective technique, useful in telecommunications industry for passing an optical telephone cord attached to a connector through pipeline,has been developed using the spiral flow. Using this technique, the cord ...A new effective technique, useful in telecommunications industry for passing an optical telephone cord attached to a connector through pipeline,has been developed using the spiral flow. Using this technique, the cord could be passed through a straight pipeline 150 meters long and a roll of vinyl tube 50 meters long. However, under the same condition, the cord could not pass through when using the turbulent flow. To obtain a high speed stable spiral flow, a nozzle with an annular slit connected to a conical cylinder was used. A pressurized fluid with no tangential flow was supplied through this slit and the fluid, passing through the conical cylinder, was deformed into spiral flow with the steeper axial velocity distribution compared to that of turbulence pipe flow due to Coanda effect and instability. As a result, the cord was attracted to the axis area of the pipe, which effectively increased the ability for the work of cord passing. This high ability for cord passing is attributed mainly to the reduction of the friction made between the cord and the pipe wall, caused by the deformation to spiral flow.展开更多
The research reported in this paper aims at developing means of Non Destructive testing (NDT) to increase the line efficiency of pipe production in oil and natural gas pipe manufacturing plants using the Standard Allo...The research reported in this paper aims at developing means of Non Destructive testing (NDT) to increase the line efficiency of pipe production in oil and natural gas pipe manufacturing plants using the Standard Allowed Minutes (SAM) method. Existing line production stations encounter difficulties in maintaining the recommended testing speed of smaller diameter pipe, due to limitations in the Visual Inspection (VI) station. We propose to implement one additional technique which will prevent the decline of line efficiency in a pipe production factory. The range of diameters identified as a problem in this research is from 254 mm to 762 mm. Microwave techniques are expected to improve the line efficiency by increasing the production of the plant. This happens as a consequence of maintaining the production rates of the identified pipe diameters, so that they equal the production output of the larger pipe diameters. We analyze the velocity traveled by the pipe through Radiographic Testing (RT) according to the VI output (production). The RT velocity is decreased for the diameters identified above, in order to maintain quality control and cover the shortcoming of the VI. The number of pipes produced is computed during shift hours of the factory and pipe lengths of the forming department are determined. We compare the output (production) of a series of NDT line stations with and without the microwave technique for the first of the three pipe cases considered in this study, classified as perfect pipe (PP), repair pipe (RP) and scrap pipe (SP). The velocity of RT stations analyzed in the paper ranges from 50 mm/s for larger diameter pipe, and decline to 16.667 mm/s for the identified diameters. The analytical calculations of line output (production) and line efficiency demonstrate the solution of this velocity problem after the microwave technique is introduced. It demonstrates that an economical and precise methodology to extend the production capability of the pipe plant has been determined.展开更多
Steel pipes are categorized into seamless pipes and welded pipes,and particularly the welded pipes’ NDT(Non-Destructive Testing)has been a challenging problem.In the case,on the basis of the presentation of welded pi...Steel pipes are categorized into seamless pipes and welded pipes,and particularly the welded pipes’ NDT(Non-Destructive Testing)has been a challenging problem.In the case,on the basis of the presentation of welded pipes,the analysis of its relevant testing key is carried out.Afterwards,the MFL(Magnetic Flux Leakage)methods for longitudinally welded line-pipes and for helically welded pipes are respectively proposed.Meanwhile,their relevant experiments are conducted,and finally the two technologies for the two types of welded pipes are verified well.展开更多
This study developed a sequential coupling finite element procedure to predict residual stresses of steel pipes with longitudinal wela／ circumferential weld and spiral weld.The results show that the residual stress i...This study developed a sequential coupling finite element procedure to predict residual stresses of steel pipes with longitudinal wela／ circumferential weld and spiral weld.The results show that the residual stress in heat affected zone（HAZ）is higher than that in weld for spiral weld pipe.For the circumferential weld pipe and spiral weld pipe,the residual stress in inner surface is higher than that in outer surface.However,for the spiral weld pipe,the residual stress in inner surface is smaller than that in outer surface.The hoop residual stress of circumferential weld pipe is higher than that of longitudinal weld pipe,while the axial residual stress of circumferential weld pipe is smaller than that of longitudinal weld pipe.The hoop stresses for circumferential weld pipe and axial stress for longitudinal weld pipe have exceeded the yield strength of base metal.With the increase of helix angle,the hoop stress decreases while the axial stress increases.For the spiral pipe（α=30° to 50°）,both the hoop stress and axial stress are relatively small.The spiral pipe（helix angle ranging from 30° to 50°） is helpful to reduce stress corrosion cracking（SCC） and it is recommended to manufacture the steel pipe.展开更多
A refined theoretical analysis for using the spiral airflow and axial airflow to purge residual water in an inclined pipe was presented. The computations reveal that, in most cases, the spiral flow can purge the resid...A refined theoretical analysis for using the spiral airflow and axial airflow to purge residual water in an inclined pipe was presented. The computations reveal that, in most cases, the spiral flow can purge the residual water in the inclined pipe indeed while the axial flow may induce back flow of the water, just as predicted in the experiments presented by Horii and Zhao et al. In addition, the effects of various initial conditions on water purging were studied in detail for both the spiral and axial flow cases.展开更多
基金Funded by Scientific Research Key Program of Beijing Municipal Commission of Education(KZ200610017010)Beijing Elitist Program Project(20041D0500517).
文摘Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps ： the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed.
文摘A new effective technique, useful in telecommunications industry for passing an optical telephone cord attached to a connector through pipeline,has been developed using the spiral flow. Using this technique, the cord could be passed through a straight pipeline 150 meters long and a roll of vinyl tube 50 meters long. However, under the same condition, the cord could not pass through when using the turbulent flow. To obtain a high speed stable spiral flow, a nozzle with an annular slit connected to a conical cylinder was used. A pressurized fluid with no tangential flow was supplied through this slit and the fluid, passing through the conical cylinder, was deformed into spiral flow with the steeper axial velocity distribution compared to that of turbulence pipe flow due to Coanda effect and instability. As a result, the cord was attracted to the axis area of the pipe, which effectively increased the ability for the work of cord passing. This high ability for cord passing is attributed mainly to the reduction of the friction made between the cord and the pipe wall, caused by the deformation to spiral flow.
文摘The research reported in this paper aims at developing means of Non Destructive testing (NDT) to increase the line efficiency of pipe production in oil and natural gas pipe manufacturing plants using the Standard Allowed Minutes (SAM) method. Existing line production stations encounter difficulties in maintaining the recommended testing speed of smaller diameter pipe, due to limitations in the Visual Inspection (VI) station. We propose to implement one additional technique which will prevent the decline of line efficiency in a pipe production factory. The range of diameters identified as a problem in this research is from 254 mm to 762 mm. Microwave techniques are expected to improve the line efficiency by increasing the production of the plant. This happens as a consequence of maintaining the production rates of the identified pipe diameters, so that they equal the production output of the larger pipe diameters. We analyze the velocity traveled by the pipe through Radiographic Testing (RT) according to the VI output (production). The RT velocity is decreased for the diameters identified above, in order to maintain quality control and cover the shortcoming of the VI. The number of pipes produced is computed during shift hours of the factory and pipe lengths of the forming department are determined. We compare the output (production) of a series of NDT line stations with and without the microwave technique for the first of the three pipe cases considered in this study, classified as perfect pipe (PP), repair pipe (RP) and scrap pipe (SP). The velocity of RT stations analyzed in the paper ranges from 50 mm/s for larger diameter pipe, and decline to 16.667 mm/s for the identified diameters. The analytical calculations of line output (production) and line efficiency demonstrate the solution of this velocity problem after the microwave technique is introduced. It demonstrates that an economical and precise methodology to extend the production capability of the pipe plant has been determined.
文摘Steel pipes are categorized into seamless pipes and welded pipes,and particularly the welded pipes’ NDT(Non-Destructive Testing)has been a challenging problem.In the case,on the basis of the presentation of welded pipes,the analysis of its relevant testing key is carried out.Afterwards,the MFL(Magnetic Flux Leakage)methods for longitudinally welded line-pipes and for helically welded pipes are respectively proposed.Meanwhile,their relevant experiments are conducted,and finally the two technologies for the two types of welded pipes are verified well.
基金supported by the Taishan Scholar Construction Funding(ts201511018)the National Natural Science Foundation of China(11372359)+2 种基金the Natural Science Foundation for Distinguished Young Scholars of Shandong Province(JQ201417)the Fundamental Research Funds for the Central Universities(15Cx08006A)the Innovation Project Foundation for Graduate Student of China University of Petroleum(YCXJ2016029)
文摘This study developed a sequential coupling finite element procedure to predict residual stresses of steel pipes with longitudinal wela／ circumferential weld and spiral weld.The results show that the residual stress in heat affected zone（HAZ）is higher than that in weld for spiral weld pipe.For the circumferential weld pipe and spiral weld pipe,the residual stress in inner surface is higher than that in outer surface.However,for the spiral weld pipe,the residual stress in inner surface is smaller than that in outer surface.The hoop residual stress of circumferential weld pipe is higher than that of longitudinal weld pipe,while the axial residual stress of circumferential weld pipe is smaller than that of longitudinal weld pipe.The hoop stresses for circumferential weld pipe and axial stress for longitudinal weld pipe have exceeded the yield strength of base metal.With the increase of helix angle,the hoop stress decreases while the axial stress increases.For the spiral pipe（α=30° to 50°）,both the hoop stress and axial stress are relatively small.The spiral pipe（helix angle ranging from 30° to 50°） is helpful to reduce stress corrosion cracking（SCC） and it is recommended to manufacture the steel pipe.
文摘A refined theoretical analysis for using the spiral airflow and axial airflow to purge residual water in an inclined pipe was presented. The computations reveal that, in most cases, the spiral flow can purge the residual water in the inclined pipe indeed while the axial flow may induce back flow of the water, just as predicted in the experiments presented by Horii and Zhao et al. In addition, the effects of various initial conditions on water purging were studied in detail for both the spiral and axial flow cases.
