Large Diameter Pipes Research Articles

Experimental Study on the Pipe-Soil Interface under the Influence of Pipe Jacking Stagnation Time

In the process of long-distance and large-diameter pipe jacking, thixotropic mud is generally injected into the outer surface of the pipe wall to reduce the frictional resistance between the pipe and the soil. The process of pipe jacking may be stopped due to various reasons such as pipe rupture and equipment damage. When the pipe is restarted after being stopped for a period of time, the interface mechanical properties usually change substantially, resulting in a substantial increase in frictional resistance compared to before the stop. However, the mechanical properties and shear mechanism of the pipe-soil interface after jacking is restarted have not been sufficiently investigated. In this paper, a series of gravelly sand-concrete direct shear tests are carried out, in which lubricant is injected into the interface between gravelly sand and concrete, and the effect of construction stagnation time is considered. The mechanical properties of the interface when the concrete pipe is restarted after stagnation is studied by the direct shear tests. The results show that the friction coefficient of pipe-soil interface increases with the stagnation time, which is determined by the thixotropic mud state and the content of gravelly sand involved in shear. In a short period of stagnation, the friction coefficient is determined by the cohesion caused by thixotropic mud and the friction angle produced by the gravelly sand involved in the shearing action. With the increase of stagnation time, the friction angle gradually becomes the decisive factor for the increase of friction coefficient.

A Cantilever-Based Flow Sensor for Domestic and Agricultural Water Supply System

Most of the existing flow sensors are expensive and limited in their capabilities for sensing bidirectional flow. Low-cost and accurate flow sensors with bidirectional sensing capability have numerous applications in the residential and irrigation sectors. Evaluation of a low-cost, cantilever-based sensor, suitable for measuring flow rates under turbulent flow conditions is presented in this article. Such sensors are reported for micro-fluidic applications but its potential application in large diameter pipes under turbulent flow has not been studied yet. A cantilever formed using a thin stainless-steel strip is used as the sensing element in the proposed sensor. One of the ends of the cantilever is firmly fitted to the inner wall of the pipe, and it bends or deflects towards the direction of the flow as a function of the flow rate. To experimentally evaluate the sensor in detail, the mean deflection angle of the cantilever is measured using a camera, and an image processing algorithm. In practice, the angle can be sensed using simpler methods. The performance of the prototype sensor has been evaluated after building an appropriate regression model. The results are subsequently expressed in terms of the mean flow velocity, thereby providing its potential utility in pipes of other dimensions. The shape of the mean flow velocity with respect to the mean angle of deflection characteristic of the proposed sensor matched well with the theoretical deflection computed. The sensor developed has given an accuracy of 3 % of full scale, for flow rates in the range of 2–15.5 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /hr. The proposed sensing mechanism can realize cost-effective, simple, and reliable flow sensors. Such sensors will find applications in residential and industrial domains.

Effects of Axial Relative Ground Movement on Small Diameter Polyethylene Piping in Loose Sand

Small diameter (42 mm) medium density polyethylene (MDPE) pipes are widely used in the gas distribution system in Canada and other countries. They are sometimes exposed to ground movements resulting from landslides or earthquakes. The current design guidelines for evaluating the pipes subjected to ground movement were developed for steel pipes of larger diameters and may not apply to flexible MDPE pipes. This paper evaluates 42 mm diameter MDPE pipes buried in loose sand under axial relative ground movement for developing a design method for the pipes. MDPE is a viscoelastic material; therefore, the behaviour of MDPE pipes exposed to landslides would depend on the rate of ground movements. In this research, full-scale laboratory tests were conducted to investigate the responses of buried pipes under various rates of relative axial displacement. Finite element modelling of the tests was used to interpret the observed behaviour using the continuum mechanics framework. The study revealed that the pulling force on the pipe depends on the rate of relative ground displacement (pulling rate). The nondimensional pulling force possessed a nonlinear relationship with the pulling rate. A rate-dependent interface friction angle could be used to calculate the maximum pulling forces using the conventional design guidelines for the pipes in loose sand. Based on the pulling force, the pipe wall strains can be estimated using the methods available for larger diameter pipes.

In-line Inspection(ILI) 기반 확률론적 구조적 파손 예측

Underground water supply pipelines are prone to functional deterioration and damage because of the occurrence and growth of corrosion over time. Therefore, to ensure the safety of such pipelines, their service life should be accurately predicted using precise inspection information. For this purpose, in-line inspection is applied for diagnosing pipelines. In this study, the structural safety of a water supply pipeline in Korea was evaluated by applying Monte-Carlo simulation, which is a stochastic analysis method, to the corrosion information of large-diameter water pipes obtained through a magnetic flux leakage sensor. For this purpose, the most appropriate probability distribution function and parameters were estimated through the statistical analysis of the data obtained from the sensor, and the corrosion growth was estimated using the probability distribution function determined from the simulation results. The safety factors for the internal pressure and external load for each pipe, which depended on the corrosion growth, could be derived probabilistically. Thus, the structural safety deterioration of the pipe over time could be estimated, and an appropriate rehabilitation method was proposed. In addition, the optimum rehabilitation time could be determined. This study will provide guidelines for the rehabilitation of water supply pipelines.

Investigating the Behaviour of Air–Water Upward and Downward Flows: Are You Seeing What I Am Seeing?

Understanding the behaviour of gas–liquid flows in upward and downward pipe configurations in chemical, petroleum, and nuclear industries is vital when optimal design, operation, production, and safety are of paramount concern. Unfortunately, the information concerning the behaviour of such flows in large pipe diameters is rare. This article aims to bridge that gap by reporting air–water upward and downward flows in 127 mm internal diameter pipes using advanced conductance ring probes located at two measurement locations. The liquid and gas flow rates are 0.021 to 0.33 m/s and 3.52 to 16.1 m/s, correspondingly, covering churn and annular flows. To achieve the desired objectives, several parameters, probability density function (PDF), power spectral density (PSD), Slippage Number (SN), drift velocity (Ugd), and distribution coefficient (C0) were employed. The flow regimes encountered in the two pipe configurations were distinguished employing a flow regime map available in the literature and statistical analysis. The obtained results were supported by visual inspection. The comparison between the present study against reported studies reveals the same tendency for the measured experimental data. The Root Mean Square Error (RMSE) method within 4% was utilized in recommending the best void fraction prediction correlation for the downward and upward flows.

Investigation of the error measurement of ultrasonic sensors for measuring water flow in open canals of irrigation systems

This paper analyzes ultrasonic flow meters that provide stability of metrological characteristics during operation, low cost of meter maintenance, high reliability and sensitivity, and high performance in large diameter pipes and open chanels. Based on the analysis, the requirements of the reclamation systems to the sensors, the causes of the error are formed. The difference between the speed of sound in the opposite direction of the flow direction or in the direction of flow in the ultrasonic sensors was studied. The measurement errors of ultrasonic sensors currently widely used in open canals are investigated graphically. Based on the analysis results, it is recommended to use an ultrasonic sensor suitable for the extreme conditions of our country.

Taking into account the curvature of non-contact zone of steel pipe billet at its bending on the pre-forming press with non-asymmetrical rocking arm of TESA 1020 line

In the production of the large-diameter steel pipes according to JUOE technology on TESA 1020 line, the steel sheet is bent sequentially on the flanging press (J-press), the pre-forming press (U-press) and the final forming press (O-press). On the flanging press, the longitudinal edge of the steel sheet is bent along the entire length of the sheet. On the pre-forming press, the steel sheet is given a U-shape by bending its central part. The final forming press gives the cross-section of the steel pipe&rsquo;s billet the shape of a circumference (O-shape). There are two main constructions of the pre-forming press for various types of the large-diameter pipe&rsquo;s production: the press with a vertical cylindrical punch and the movable horizontal reduction beams with the cylindrical rollers and the press with a vertical cylindrical punch and a movable swinging rocking arm with the cylindrical reduction rollers. In given paper, we consider the forming of a steel pipe billet on the pre-forming press with an non-symmetrical swinging rocking arm having the cylindrical reduction rollers of different diameters. The hardening zone of steel is described by the nonlinear dependence that takes into account the Young&rsquo;s modulus, the hardening modulus, the yield strength and the ultimate strength of steel. The calculations take into account the non-linearity of the transversal neutral line of steel sheet (pipe billet) in the non-contact zone between the punch and the reduction rollers of the swinging rocking arm. When forming a pipe billet on the final forming press, the effects of Bauschinger, Masing and Hencky for the pipe billet&rsquo;s zones with sign-alternating bending during forming process on TEWA 1020 presses are taken into account.

Advancement of Roll-Gap Control to Curb the Camber in Heavy-Plate Rolling Mills

The quality of steelwork products depends on the geometric precision of flat products. Heavy-plate rolling mills produce plates for large-diameter pipes and for use in shipbuilding, mechanical engineering, and construction. This is why the precision requirements are so stringent. Today’s Mills 5000 produce flat products of up to 5 m in width; the operation of these units shows ‘camber’ defects and axial shift of the roll at the stand exit point. This induces greater loss of metal due to edge trimming and involves a higher risk of accidents. These defects mainly occur due to the asymmetry in the roll gap, which is in turn caused by their misalignment in rolling. As a result, the feed varies in gauge, and the strip moves unevenly. The paper’s key contribution consists in theoretical and experimental substantiation and development of a set of control methods intended to address roll-gap asymmetry. The methods effectively compensate for the asymmetry resulting from the “inherited” wedge, which preexists before the strip enters the stand. They also compensate for the “ongoing” roll misalignment that is caused by the difference in force on the opposite side of the stand during rolling. This comprehensive approach to addressing camber and axial displacement of the feed has not been found in other sources. This paper presents a RAC controller connection diagram that ensures that the roll gap is even across the feed. The paper notes the shortcomings of the design configuration of the controller and shows how it could be improved. The authors have developed a predictive roll-gap asymmetry adjustment method that compensates for the deviations in gauge during the inter-passage pauses. They have also developed a method to control gap misalignment during rolling. The paper showcases the feasibility of a proportional-derivative RAC. The methods have been tested by mathematical modeling and experimentally. The paper further shows oscillograms sampled at Mill 5000 after implementing the developed solutions. Tests confirm far better precision of the screw-down mechanisms on the opposite sides of the stand. This reduces the variation in gauge across the feed and thus curbs the camber defect. As a result, the geometry of the flat improves, and less metal is lost in trimming. The paper further discusses how the RAC controller interacts with the automatic gauge control system. The conclusion is that these systems do not interfere with each other. The developed systems have proceeded to pilot testing.

Impedance of Inner Saturated Soil to Horizontally Vibrating Large-Diameter Pipe Piles

An analytical solution for the inner soil impedance of saturated soil to a horizontally vibrating large-radius pipe pile was presented. Based on the porous media theory and the assumption that the vertical normal stress is zero, the closed solution of the inner soil impedance of the saturated soil to the movement of the large-diameter pipe pile is obtained. This analytical solution considers the influence of saturated soil parameters on the impedance of the core soil of large-diameter pipe piles. Through numerical examples, the variation law of the inner soil impedance with pile radius, pile length, dimensionless frequency, compression coefficient, effective permeability coefficient, and porosity was analyzed and the pile radius corresponding to effective inner soil impedance is determined.

Problematic issues of high-carbon electrical steel production

Currently, wire rod for the production of wire from low-, medium- and high-carbon unalloyed and alloyed steels for springs, ropes, metal cord, welding electrodes and copper-plated wire for welding building structures, ship hulls, large-diameter pipes and main gas and oil pipelines is in demand on the world market. for the production of which it is not necessary to carry out softening annealing before drawing the wire rod or on an intermediate size of wire. The most responsible types of wire rod made of high carbon steel are wire rod, intended for the production of metal cord and high-strength reinforcing ropes. The above-mentioned products must have high consumer properties, the level of which largely depends on the formation of the structural state of the metal, including in the process of accelerated cooling from rolling heating. Currently, the volume of wire rod production in the world exceeds 50 million tons, which is explained by the wide range of finished products made from it - ropes, metal cord, springs, needles, strings, nets, fasteners, welding electrodes and other metal products. According to GOST 2590-2006, wire rods are round profiles with a diameter of 9.0 mm and less, round profiles with a diameter of 10.0 mm and more are classified as small-grade rental In foreign and domestic literature, wire rod is sometimes considered to be a round rolled product made of carbon, low- and high-alloy steels, produced on continuous wire mills and wire lines of small- and wire looms, regardless of the diameter, which reaches 26 mm. The main part of the wire rod is directed for further processing at steel wire and hardware enterprises. In recent years, the volume of production of wire rod from continuously cast blanks with a high degree has increased metallurgical purity, including for the production of particularly responsible products. For example, such as a metal cord, which has a high level of endurance, and in terms of strength, this type of product is divided by normative strength into normal (NT 2400 ... 2750 N / mm2), high (HT 2750 ... 3100 N / mm2), super high (ST 3100... 3450 N / mm2) and ultra-high-strength (UT 3450 ... 3750 N / mm2). Considerable attention is paid to the improvement of the high-carbon steel smelting process. Various methods are offered to ensure the purity of steel and the formation of high strength properties. To improve the plasticity of steels, alloying additives with a significant content of carbon and manganese are widely used limited nitrogen content. Processing at the ladle-furnace installation in the process of high-carbon smelting was analyzed steel with improved plasticity for cold deformation.

Design Equations for Large Diameter Buried Steel Pipes Inspired by the Modified Iowa Formula

Abstract The performance of large diameter pipes under construction loads is inherently coupled with knowledge of the complex soil–pipe system. Current methods do not cover all the different combin...

Precise prediction of the drag reduction efficiency of polymer in turbulent flow considering diameter effect

One important issue for drag reduction of turbulent flow with polymers is the pipe diameter effect. Although this scale-up effect has been extensively investigated, there are still debates. For instance, when using the traditional scaling law to predict the friction factor in pipe flow of wide pipe diameters, the relative errors between experimental data and predicted values can be up to 1000%. This paper develops a new method to predict the friction factor in pipe flow applicable to a wide range of pipe diameters. The new method developed in this study transforms the Reynolds number (Re) vs friction factor (f) to log10(Ref) vs 1/f in the Prandtl–von Karman coordinate, where the latter two parameters are correlated on straight lines. We find that the slope and intercept of these straight lines can be predicted by empirical correlations involving diameters and polymer concentrations. Thus, if Re and f from a pipe flow of small diameter are known, these two correlations for slope and intercept can predict the cases for large pipe diameters. With our method, most relative errors between the predicted values and experimental data are within 20%, much better than the traditional scaling law. Finally, we point out the physical meaning of the slope and intercept, and make it clear why the previous scaling law becomes not reliable when it is employed to predict the friction factor for pipe flow with a too wide range of pipe diameters.

Institutions to the rescue: Untangling industrial fragmentation, institutional misalignment, and political constraints in the Russian gas pipeline industry

This article examines the institutional setting implemented by a fragmented industry to face a technologically and politically challenging environment. It does so through the lens of recent developments in new institutional economics building on the Williamsonian contributions about hybrid organizations and the Northian contributions about institutional layers. The resulting analytical framework throws light on the institutional design implemented by the Russian manufacturers of large diameter pipes, a strategic segment of the natural gas supply chain. Examination of this arrangement shows the key role of intermediary institutions, coined ‘meso-institutions,’ in coordinating parties that nevertheless remain competitors. However, this ‘economizing strategy,’ backed by the central government, collides with the ‘anti-monopoly’ strategy that the same government intends to implement. Based on interviews and private and public data and documents, this narrative shows the impact of technology on organizational choices and the theoretical gains to be expected from differentiating institutional layers when it comes to understanding the many challenges an industry faces.

Numerical Investigation of the Method of Structural Performance and Rehabilitation of Large-Diameter Buried Steel Pipes Subjected to Excessive Deformation: A Case Study of China

Large-diameter buried steel pipes (BSPs) play critical roles in water transport for major water diversion and hydropower projects. Due to poor pipe-soil composite system properties and installation conditions, they are prone to excessive deformation, resulting in safety hazards. This paper takes a BSP project subjected to excessive deformation as an example. A simplified numerical model is first established to analyze the structural performance, including the stress and plasticity, and the relationship between the stress and deformation of the pipe. Furthermore, a jacking method to rehabilitate the pipe-soil composite system is conducted to explore its influences on pipe deformation, stress, and plasticity. The results show that considerable bending stresses occur in the pipe and that sections of the midspan and stiffening ring are in the pure bending state and eccentric bending state, respectively. Areas of high stress and plasticity center at the crown, springline, and invert of the pipe, and steel pipes with ring deformation of 8.9% can be continued to be used, as the full yielding of the pipe walls occurs at the ring deformation of 15.8%. The jacking method is an effective solution for the rehabilitation of BSPs subjected to large deformation and can reduce pipe deformation significantly while increasing the stress at the pipe crown and the pipe plasticity only slightly.

Experimental Investigation of Oil-Water Two-Phase Flow in Horizontal, Inclined, and Vertical Large-Diameter Pipes: Determination of Flow Patterns, Holdup, and Pressure Drop

Summary Liquid-liquid phase flow in pipes merits further investigation as a challenging issue that has very rich physics and is faced in everyday applications. It is the main problem challenging the fluid flow mechanism in the oil and gas industry. The pressure gradient of liquid flow and flow pattern are still the topics of numerous research projects. In this paper, the emphasis is on further investigation to research the flow pattern, water holdup (HW), and pressure decrease for vertical, horizontal, and inclined flow directions of oil and water flows. Test section lines of 4.19-in. (106.426 mm) inner diameter (ID) and 5-m horizontal, 5-m inclined, and 5-m vertical test sections were serially connected. The experiments were conducted at 40°C using 2-cp viscosity oil and tap water, and oil density of 850 kg/m3, at the standard conditions. Fifty experiments were executed at 250 kPa at the multiphase flow test facility, with horizontal, upward (0.6° and 4°), downward (−0.6° and −4°) hilly terrain and vertical pipes. The oil and water superficial velocities were changed between 0.03 and 2 m/s. This evidence was obtained using video recordings; the flow patterns were observed, and the selection of each flow pattern was depicted for each condition. For horizontal and inclined flow, new flow patterns were documented (e.g., oil transfer in a line forms at the top of the pipeline, typically at high water rate, and water transfer at the lower part of the pipe at a high oil rate). The data were taken at each flow condition, resulting in new holdup and pressure drop. The results show that the flow rate and the pipe inclination angle have major impacts on the holdup and pressure drop performances. In the vertical flow, a clear peak was demonstrated by experiments after the superficial oil velocity reached a certain value. This peak is known as phase inversion point, where after this peak, the pressure starts declining as the superficial oil velocity increases. Also, slippage has been observed after varying inlet oil flow rates between the two phases. The experiments showed that with minor alteration in the inclination angle, the slippage was significantly changed. This study presented new experimental results (measured mainly at horizontal, inclined, and vertical flow conditions) of HW, flow pattern, and pressure drop. These findings are key evidence of the evolving oil-water and flowline estimate models.

Modeling Large Diameter Industrial Pipe Insulation Performance

As previously presented, reducing industrial noise emission utilizing jacketed pipe insulation is critical to reducing noise in industrial spaces. The ISO 15665 standard defines a testing process for measurement of the acoustical performance of installed and jacketed pipe insulation systems. To provide a cost-effective method for evaluating various types of multilayered jacketed pipe insulation a model was developed. The model accurately estimates the performance of single, and multilayered, jacketed pipe insulation. Validating the use of the model to very large pipe diameters is highly desirable as the cost to test is significantly higher than testing the medium or small diameter pipe insulation. The estimated insertion loss result from the model is compared to validation testing results for large diameter jacketed pipe insulation are reported herein.

Development and mastering of technologies of production at PJSC MMK a new generation steel rolled stock for m a in pipelines

In view of arising needs of Russian oil and gas sectors, elaboration and implementation into series production competi­tive pipe products became an actual task for domestic enterprises of metallurgical industry. Generalized results of elaboration of chemical compositions and automated technologies of sheet rolled stock of new generation production from low-alloyed pipe steels of various strength classes at PJSC MMK presented. It was shown that the selected chemical compositions ensure forming finedispersed ferrite-bainite structure with bainite of granular morphology in a wide range of cooling rates. The elaborated technological modes of sheet rolled stock production from pipe steels stipulate for elimination considerable growth of austenite grain at heating before the rolling, refinement of austenite grains due to recrystallization processes, forming of extensive subgrain structure of austenite at plastic deformation, forming disperse structures during phase transformation in the process of controlled accelerated cooling; forming of extensive fragmented structure in а-phase. The level of strength, tough-plastic properties and resistance against brittle destruction (based on results of tests with a falling weight with determination of tough component share in the break of full-thickness samples) of sheet rolled stock of pipe steels with various chemical composition of PJSC MMK production was demonstrated. Results of study of tests the sheet rolled stock of high-strength steels for pipes of large diameter presented. Objects of the elaborated pipe steels implementation indicated.

Experimental and mathematical methods for calculation of residual stresses in production of welded pipes

The results of physical and mathematical modeling of the stress-strain state of metal and residual stresses during plastic deformation of a sheet blank and welding of large-diameter pipes are generalized. One of the analytical methods for calculation of residual stresses during elastoplastic deformation of a rectangular bar and a wide strip is described. From the standpoint of continuum mechanics, it is shown that under the action of a bending moment, tensile stresses appear in the outer layers, and compressive stresses appear in the inner layers, which change sign during unloading and residual stresses remain in the metal, compressive stresses in the outer layers, and tensile stresses on the inner surface. As a result of the studies carried out, the authors for the first time obtained a picture of residual stresses distribution and found that at each technological operation of the formed pipe billet after its completion, tangential and axial residual tensile stresses &sigma;остmax/&sigma;в &le; 0,31, act along the entire outer perimeter and length, which after expansion-calibration of pipes decrease to the magnitude &sigma;т &sigma;ост/= 0,23&sigma;в and &sigma;ост&infin;/= 0,18&sigma;в. Ii was established that the value and distribution of residual stresses are significantly influenced by the blank shape, the order of welds imposition, welding modes and mechanical properties of the metal. This conclusion was also confirmed by experimental studies of residual stresses, which were obtained by X-ray diffractometry and sequential etching of surface layers using the MerCulon &laquo;Tensor-3&raquo; system. The results of experimental studies have shown that during plastic deformation of the sheet blank and after welding, residual tensile stresses are observed on the outer surface in the pipe metal and in the weld, which can cause pipeline failure. The paper describes the results of numerical modeling of non-uniformity of the stress-strain state and residual stresses in the metal of pipe processing at all stages of production according to the JCO scheme: bending of the sheet edges &rarr; forming on a step-forming press &rarr; re-forming of the &laquo;spline pipe&raquo; - a pipe profile with divorced edges &rarr; calibration - pipe expansion. Based on the results of modeling by the finite element method, it is shown that the required geometric shape of the pipe and the dimensional accuracy of the LDP diameter are achieved when expanding the workpiece with an ovality of no more than 5 mm, while ensuring high-quality assembly and welding of edges of pipes to be joined in the line of the pipeline system.

New Analytical Solution to Predict the Vertical Impedance of a Large-Diameter Pipe Pile in Soil Considering Wave Propagation in Visco-Elastic Continuum

According to the theories of wave propagation in visco-elastic continuum and Rayleigh-Love rod, a simplified model in axisymmetric conditions for the longitudinal vibration of large-diameter pipe pile (LDPP) in radially heterogeneous surrounding soil with viscous damping is presented. The relevant analytical solution for dynamic impedance at pile head is derived by using complex stiffness transfer method, which is also validated via independent comparisons with previous solutions. Besides, parametric analyses are carried out to reveal both the radial heterogeneity of surrounding soil and the lateral inertia effect of pile shaft on the dynamic impedance of LDPP. The obtained analytical solutions are suitable for the longitudinal vibration issues of floating LDPP in visco-elastic surrounding soil with radial heterogeneity, which can be conveniently degenerated to describe the longitudinal vibration of a floating solid pile in soil with radial heterogeneity as well as a floating LDPP or solid pile in radially homogenous soil.

Research on local compensation technology of large diameter steel pipe with heterogeneous structure and analysis of application

When large-diameter steel pipes have special structures with stiffening rings, grouting holes, etc., the electrostatic spray epoxy powder anti-corrosion process is likely to produce large temperature differences due to the sudden thickness changes during heating, which cannot meet the temperature requirements of powder spraying. This paper designs a set of automatic temperature compensation technology for large-diameter steel pipes with stiffening rings and grouting holes, which aims to solve the problem of uneven heating of stiffening rings and grouting holes in the medium frequency induction heating powder spraying process. Through the method of “intermediate frequency heating + stiffening ring temperature compensation”, the inner and outer parts of the steel pipe are heated evenly and the temperature difference is reduced. The temperature difference between the inner wall of the steel pipe is reduced to 3∼15°C in the area of the stiffening ring, and the temperature is reduced in the area of the grouting hole. The difference is reduced from 70°C to 57°C to 20°C, the temperature difference is controlled within the allowable range of technical requirements, and the temperature compensation effect is good. The process has the advantages of simple device structure, high work efficiency, and small temperature difference in the spraying area, and is suitable for use on similar large-diameter steel pipes or other hydraulic metal structures.