Identification and evaluation of human errors of Epoxy control room operators of a pipe Mill company using HEC technique

Introduction: In many workplaces today, the incidence of human error can lead to catastrophic accidents in which human error is the main cause of accidents. Due to the vital role of the control room in guiding and controlling various sites of the pipe industry, especially the outer coating sector, the incidence of any error can lead to human accidents, damage to machinery, interruption in production. This study aimed to identify and evaluate human error by Human Error Calculator (HEC) method in the epoxy control room of a pipe mill company. Materials and Methods: In the present descriptive cross-sectional study, the HEC method was used to identify and evaluate human errors. The HEC technique is provided by Risk Map Company, in which the probability of human error is based on five factors affecting the occurrence of human error, including a degree of urgency, complexity, importance, degree of individual skill, and task repetition, using a disk-shaped tool called Risk Disk is determined through direct observation, available instructions and interview with the head of the mentioned unit. Results: According to the results of this study, out of 11 identified tasks, five job tasks with a risk number of 70% have a high probability of human error, four job tasks with a risk number of 50%, and one job task with a number There is a 40% risk of moderate human error, And a job task with a 20% risk number has an increased chance of human error. Conclusion: The results of the present study showed that the HEC method is easy to use and is a simple and useful tool for professionals to calculate the probability of human error. In addition, HEC is a practical, effective and beneficial method for managers to reduce human error.

Chemical Selection for Flocculation of the Sludges Produced During Lime Neutralization of Acidic Spent Pickling Solutions and Rinse Water from Steel Pipe Mill

Acidic spent pickling solutions and rinse water are produced during steel pipe acid pickling. They are usually neutralised with lime in a neutralisation plant and pumped in the form of a wet sludge to a landfill. This is one of the main environmental issues of Russian steel mills. The implementation of sludge treatment units, including equipment for sludge polymer conditioning and dewatering, is an import consideration when seeking to reduce the impact of steel mills on human health and the environment. The researches results of polymer conditioning of the aggressive wastewater sludges by flocculants are reflected in the paper. Sludge samples were obtained from the neutralisation plant of an Ural’s steel pipe mill. Sludges of two types were investigated: the sludge which is formed in clarifiers during spent pickling solutions neutralization with lime and the sludge which is formed in clarifiers during rinse water neutralization with lime. During the work non-ionic, cationic, and anion flocculants Praestol® efficiency was estimated. The shortest time of water capillary suction from the flocculated sludge was accepted as efficiency criterion of flocculant processing. It was defined with use of the capillary suction timer Fann® and Whatman® 17 chromatographic paper. It is established that: non-ionic focculant Praestol® 2500 dose of 4–5 g/kg dry solids is effective for conditioning of the sludge produced during lime neutralization of acid spent pickling solutions; the anionic flocculant Praestol® 2540 dose of 1.5–2 g/kg dry solids is effective for conditioning of the sludge produced during lime neutralization of acid rinse water. The empirical response surfaces and the contour plots showing the relationship between capillary suction time and a dosage of flocculant and a charge density (% hydrolysis) of a flocculant were reveived. Keywords: steel pipe mill, acid pickling, wastewater, sludges, flocculants, capillary suction time

Effect of Squeeze-out and Sizing Ratio to The Residual Circumferential Stress of HFW Pipe

Residual circumferential stress originates from pipe forming process has a negative impact on the pressure carrying capacity; therefore it is necessary to keep the level of residual stress as low as possible and distributed uniformly around the pipe. Manufacturing of HFW (High-Frequency Welded) pipe involves pinching, bending, forming, welding, squeezing, sizing and straightening processes in several stages which produce both elastic and plastic deformation. Those processes produce residual stresses in the pipe wall in the circumferential and longitudinal directions. This paper presents the result of the trial test to investigate the effect of squeeze-out (SO) and the sizing ratio (SR) to the residual circumferential stress on HFW pipe. The trial was performed at PT INDAL STEEL PIPE (ISP) pipe mill, on pipe API 5L L360MO PSL2, nominal Outside Diameter (OD) 273 mm, wall thickness 12.7 mm. The SO was 0.7t and 0.9t, while the SR was set at 0.5 %, 0.8 %, and 1.0 %.

Mastering of seamless pipes production from martensiticclass stainless steel of 13Cr grade type at the JSC “VTZ” TPA 159–426 pipe mill

Mastering of offshore deposits of hydrocarbons require application of new types of pipe products, capable to effectively work under conditions of constant impact of aggressive media. In this connection new tasks arose to produce seamless hot-deformed pipes made of martensitic class stainless steels with increase chrome content. Mastering of such pipes production is connected with necessity to overcome a series of technological problems. The problems are stipulated by metal structure peculiarities, appeared in low plasticity and narrow temperature range for hot deformation, increased inclination to defects formation in the rolling process, as well as more intensive wear of rolling instrument, in particular of that of piercing mill. Main stages of seamless pipes production mastering, made of type 13Cr steel grades at TPA 159–426 line with TPZ-3 continuous mill of JSC “Volzhsky Pipe Plant” presented. The complex of measures for the noted problems overcoming, including semi-product type selection, piercing mill rolling instrument calibration change, as well as deformation regimes and other measures presented. The elaborated complex of measures allowed providing of pipes manufacturing of necessary quality for PAO “Gasprom” demand as per TU 14-3Р-129–2015 specifications.

Analysis and Simulation of the UOE Pipe Production Processing by Finite Element Method

Large-diameter pipes used in offshore applications are commonly manufactured through the UOE process. The plate is crimped along its edges, formed into a U-shape and then pressed into an O-shape between two semicircular dies. The pipe is welded closed and then circumferentially expanded to obtain a highly circular shape. In this study, the two-dimensional finite element model of the whole processing of the UOE pipe production has been established, including large deformation and complex contact. The deformed geometries of different steps and distribution of the equivalent plastic strain and variation in load are analyzed. This research is helpful in UOE forming process design and evaluating the capability of the pipe mill.

Using Ring Stiffness to Calculate the Elastic Modulus of Steel-Plastic Composite Pre-Insulated Pipe

Elastic modulus of the pipe mill is one of the most important figures, which decides the character of the mechanics of materials. It is usually gained by experiments or finite element analysis. Combining computing formula of ring stiffness of buried pipeline and test results of ring stiffness of new straight buried thermal pipe (steel-plastic composite pre-insulated pipe), this article uses moment of inertia and equivalent section method to calculate elastic modulus of this pipe catalogue. By comparing with practical test results, the article testifies that this method could be probably used in directly buried installation.