Pipe Line Research Articles

Mechanical study and equations for gravity flow pipe liners stretching across ring fractures or joints under shear action

Cured-in-place-pipe (CIPP) liners have been widely used in rehabilitation of gravity flow pipelines. However, the host pipe rehabilitated by the CIPP liner may be subject to shear force and shear displacement at the joint. In this study, a finite element model of a rigid host pipe with liner under shear action is established and used to study the resulting behaviour. Controlling factors such as the gap spanned by the liner between host pipes across the joint, diameter, the liner thickness, the elastic modulus of the liner, and the coefficient of friction between host pipe and liner are studied. The liner stress, displacement, and shear force are reported. Shear stiffness and stress equations are then fitted based on 286 data points. The results show that the maximum stress on the inner surface of the liner occurs at the shoulder and haunch, and the maximum stress on the outer surface occurs at the springline. The inner surface stresses at the crown and invert decrease with increases in liner-host pipe friction, but increase at the shoulder and haunch. Coefficient of Friction has almost no effect on the stresses that develop on the outside surface of the liner.

Autonomous Underwater Pipe Damage Detection Positioning and Pipe Line Tracking Experiment with Unmanned Underwater Vehicle

Autonomous Underwater Pipe Damage Detection Positioning and Pipe Line Tracking Experiment with Unmanned Underwater Vehicle

Bending Response and Design Equations for Gravity-Flow Pipe Liners Passing across Ring Fractures or Joints

Bending Response and Design Equations for Gravity-Flow Pipe Liners Passing across Ring Fractures or Joints

Studying the Microstructural Evolution in a Hot-Rolled Thick Gauge Microalloyed Line Pipe Steel

Studying the Microstructural Evolution in a Hot-Rolled Thick Gauge Microalloyed Line Pipe Steel

Real time detection of fatigue cracks on steel structures by applying square wave induction

For years the Eddy currents principle together with inductive thermography have been applied to detect cracks or defects in metallic machine components. In case a component has a crack, by inducing Eddy currents within a coil, it is possible to cause a temperature increase in the edges of the crack. This temperature variation can be observed by using an infrared camera. Thus, the crack is registered and observed in the infrared images, which are later analyzed. However, currently used systems require an enormous amount of power and a long time for image processing. For this reason, applying this method to large steel structures such as bridges, cranes, wind power towers, pipe lines or offshore oil stations has been much more complex. To overcome these limitations, a light portable system that optimally recreates the Eddy currents principle has been developed and used in this research. This system generates a square wave AC voltage, it uses considerably less power and it is capable of detecting cracks in real time. This paper presents the simulations and experiments carried out on two different structural steel specimens to demonstrate the efficiency of the system and its potential in the field of nondestructive testing.

Sewerage surveillance tracking characteristics of human antibiotic resistance genes in sewer system

Sewage surveillance is widely applied to track valid human excretion information and identify public health conditions during corona virus disease 2019 (COVID-19) pandemic. This approach can be applied to monitor the antibiotic resistance level in sewers and to assess the risk of spreading antibiotic resistance in municipal wastewater systems. However, there is still little information about human antibiotic resistance occurrence characteristics in sewer system. This study conducted a field trial for whole year to advance understanding on spatial and temporal occurrence of antibiotic resistance genes (ARGs) in gravity sewerage. The spatial distribution of ARGs along the drainage pipe line (from human settlements to wastewater treatement pant (WWTP)) was insignificant, which may be affected by irregular human emission alongside the pipeline. The correlation between ARGs and antibiotics in sewage was insignificant. The temporal distribution showed that the effect of temperature on ARGs abundance was evident, the ARGs abundance in sewage was generally higher during the cold season. Metagenomic analysis revealed that the detected ARGs were mainly distributed in Proteobacteria (47.51 %) and Antinobacteria (20.11 %). Potential hosts of ARGs in sewage were mainly identified as human gut microorganisms, including human pathogenic bacteria, such as Prevotella, Kocuria, and Propionibacterium, etc. This study provides a new insight into the sewerage surveillance tracking characteristics of human ARGs in sewer system, and suggesting that the sewage-carried ARGs surveillance is a promising method for assessment and management of antibiotic resistance level on population size.

Establishment of a one-dimensional model for CO2 Pipeline rupture process and design recommendations

Pipelines serve as a critical means of transporting CO2 within Carbon Capture, Utilization, and Storage (CCUS) technology. Elevated transport pressures may lead to unforeseen pipeline ruptures. To provide practical recommendations for the design of CO2 pipelines and mitigate the risk of ruptures, this study establishes a one-dimensional Homogeneous Equilibrium Mixture (HEM) model. The model is currently used to predict the decompression behavior in existing pure CO2 rupture tests. Future work will address rupture tests and predictions involving impure CO2. The results indicate that due to differences in pressure reduction caused by decompression waves, the likelihood of long-range ruptures occurring in density CO2 pipelines is lower compared to supercritical CO2 pipelines. The crack propagation velocity and crack arrest pressure of pipelines designed according to ASME B31.3 are calculated using the High Strength Line Pipe Committee (HLP) model. Although the crack propagation velocity is lower than the decompression wave speed, the crack arrest pressure may fall below the rupture pressure, with the pressure at 1.6 m from the rupture point remaining above the crack arrest level for 1 ms post-rupture, a duration that is especially prolonged in larger-diameter pipelines. It is recommended to consider additional thickness beyond the calculated minimum thickness.

Experimental response of a fusible PVC pipe with service connections to axial pullout

This paper investigates the axial pullout response of a fusible polyvinyl chloride (FPVC) main pipe with two service connections. A large-scale pullout experiment in dense sand was conducted to investigate the behaviour of service lines to axial pullout of the main pipe and the impact of service connections on the main pipe’s axial pullout resistance, axial force distribution, and moment distribution. The study assesses the response of both crosslinked polyethylene (PEX) and copper service lines as well as the role of goosenecks. Distributed fibre optic sensors (DFOS) have provided insight into the strain distributions along the main pipe and service lines. The experimental results have shown that service connections significantly increase the axial pullout resistance of the main pipe when compared to a previous test on an identical pipe without service connections. The movement of the service connections was found to reduce the earth pressure in a region behind the service connection. Hinging of the service saddles was observed to result in single curvature bending of the service lines. DFOS data along the main pipe has been used to approximate the individual load-displacement responses of the PEX and copper service connections.

Advanced exergoeconomic analysis and mathematical modelling of the natural gas fired gas turbine unit used for industrial cogeneration system

In this study, mathematical model of advanced exergoeconomic analysis (ADEXEC) basing on advanced specific exergy cost (ADSPECO) and advanced exergy-cost-energy-mass (EXCEM) (ADEXCEM) methods are applied to the industrial cogeneration system (COGEN) which consists of natural gas fired gas turbine unit (with combustion chamber (CC), turbine (GT) and air compressor (AC)), pipe line (PL), wall (WD) and ground (GD) tile dryers under the dead state conditions of 10 °C, 15 °C, 20 °C, 25 °C and 30 °C. According to ADSPECO analysis; although CC ($6.97/GJ) has the lowest unit fuel exergy cost among the components, it has the highest exergy destruction cost rate ($252,391/hour at 30 °C) due to its high exergy destruction value. Although more than 40 % of the exergy destruction cost rate in the COGEN system is detected in CC, WD (105.541 $/h at 30 °C) and GD (107.499 $/h at 30 °C) which together account for more than 67 % of COGEN's avoidable exergy destruction are understood to be the first components to focus on. The fact that the exergy destruction cost rates of all components except PL is higher than the exogenous part of the endogenous part at all dead state temperatures reveals the weakness of the relationship between the components.

Environmental Impact Assessment of Volatile Organic Compound Emissions during Trenchless Cured-in-Place Pipe Installation

Cured-in-place pipe (CIPP) lining is a widely adopted method for pipeline renewal, offering advantages such as rapid installation and cost-effectiveness. However, concerns regarding the environmental impacts of volatile organic compound (VOC) emissions during the installation process have raised issues regarding the CIPP method. The literature review conducted in this paper indicated the need for stringent monitoring and management practices to mitigate adverse effects, emphasizing the importance of safe installation protocols. This paper presents the initial results of a case study focusing on VOC emissions, specifically investigating non-styrene vinyl ester resins and water curing. To capture emissions from CIPP activities, the methodology involved air sampling using various equipment, including photoionization detectors (PID), summa canisters, passive worker sampler sorbent tubes, and method 13 cartridges. The preliminary findings indicate that non-styrene vinyl ester resins resulted in VOC emissions well below the exposure limits set by OSHA and USEPA, with the highest measured concentration being 2.54 ppm. This demonstrates that non-styrene resins can significantly reduce environmental and health risks. The future phases of this project will explore different resins and curing methods to further validate these findings and develop comprehensive guidelines for safe CIPP installations.

Mechanical response and stress equation of pressure pipe liner passing across circular corrosion

Corrosion is one of the most common forms of damage to pressure pipes. CIPP liner can improve the mechanical properties of the pipe with corrosion. It is very important to study the mechanical response of corrosion pipes rehabilitated by CIPP liner. In this study, a three-dimensional finite element model of a pressure pipe rehabilitated with CIPP liner under the condition of circular corrosion is established, and the model is evaluated by using the experimental and analytical results. Afterward, the influence of each parameter on the stress and displacement of the liner is analyzed. Finally, the liner stress calculation equation is obtained based on 870 sets of data. The results show that the finite element results are in good agreement with the experimental and analytical results. The maximum stress of the liner first occurs at the center of the corroded circle, and as the corrosion diameter increases, the maximum stress gradually shifts to the edge. The maximum stress of the liner increases first and then tends to be stable with the increase of the corrosion diameter, and the friction coefficient has little effect on the liner stress.

A Limited Evaluation of the Applicability of NACE MR0175/ISO 15156 H2S Limits to Supercritical CO2 Pipelines

In an earlier paper one of the authors raised the question of whether the hydrogen sulfide (H2S) partial pressure threshold of 0.05 psia (0.3 kPa) for cracking of steels from sulfide stress cracking is pertinent to dense phase carbon dioxide (CO2) systems in which there is no free gas phase. This paper presents a limited test of the pertinence of this threshold value in Supercritical CO2. Autoclave tests of four-point bend beam specimens of API 5L Grade X80 line pipe steel at 0.05 psia (0.3 kPa) and 0.20 psia (1.38 kPa) H2S were performed and the samples were examined after testing for cracking. In addition, the test conditions were modeled with the OLI Studio software to determine the H2S fugacities and H2S concentrations in the brine phase. No cracking was found after 30 d of exposure.

Enhancing ASTM B424 UNS N08825 Long Seam Weld Liner Material with Annealing Quenching Techniques in the Cladding Process on the Surface of Steel Pipes

The use of cladding methods in manufacturing corrosion-resistant pipes is crucial for industries such as oil and gas, chemical plants, and pressure vessel manufacturing. This study focuses on ASTM B424 UNS N08825, a corrosion-resistant alloy (CRA) to be used as the surface layer for steel pipes. The cladding method involves forming CRA sheets into longitudinal pipes, followed by welding the joints, annealing, and rapid cooling before high process expansion to surface layer the steel pipes. At a temperature of 930-990°C, the annealing process aims to reduce stress and improve material properties, followed by rapid cooling to stabilize the microstructure. Various tests were conducted on the CRA liner pipes with or without annealing and quenching, including tensile testing, hardness testing, chemical composition analysis, and microstructure examination. The results showed that the material's ultimate tensile strength and hardness significantly increased after the treatment, with better uniformity in the microstructure. This study concludes that annealing and rapid cooling enhance the mechanical properties and stability of ASTM B424 UNS N08825, allowing the cladding process on steel pipe surfaces to be performed flawlessly and making it suitable for high-performance applications in corrosive environments.

Usulan Perancangan Pemasangan Alarm Detector dan Sprinkler pada Kampus C Universitas Dirgantara Marsekal Suryadarama

The building facilities currently used by Universitas Dirgantara Marsekal Suryadarma (Unsurya) is Campus A and Campus B and the new Campus C. In this research examined campus C Unsurya, which is a three (3) floor building. The building must be equipped with reliable fire safety facilities. There are several functions of space that can trigger fires, namely electrical installations and flammable building materials. Based on the background above, adequate active protection means are needed in accordance with applicable regulations. Cause-and-effect diagrams / Fishbone diagrams are used to analyze the factors that cause fire hazards. The factors that influence and cause fire hazards can generally be classified as follows: Workers, Raw Materials, Machines, Methods, and Environment. 5W+1H Quality using to determine recommendation. Based on calculations, it was determined to place 132 sprinklers to overcome the danger of fire with a quantity of ¾" pipe material with a pipe line 460 meters long. Meanwhile, the water supply is 277 m3/minute. With the required water supply, a pump with a pump capacity capable of producing 277 m3/minute is needed. With this capacity, three pumps with a capacity of 100 m3 /hour and one spare pump can be used. A water storage tank is needed for 300 m3 for 60 minutes with a length of 4 meters, width of 5 meters and depth of 1.5 meters. It is proposed to use a Standard Operating Procedure (SOP) regarding K3 or safety and how to handle fire hazards in the Unsurya Campus C building which includes improvements to human factors, materials, machines, methods and the environment of the Campus C Unsurya.

Study on the Bearing Capacity of the Polyethylene Pipe–Cured-In-Place Pipe Liner Composite Structure under External Pressure

Cured-in-place pipe (CIPP) technology is used to repair deformed municipal polyethylene (PE) pipes caused by design flaws, construction issues, or external loads. However, research on CIPP for PE pipes is limited, restricting its broader application. This research focuses on the mechanical response characteristics and failure modes of the composite PE pipe–CIPP liner structure under external loads. Using experimental setups involving comparative test groups with different diameters and wall thickness ratios (DR values, defined as the ratio of the pipe’s outer diameter to its wall thickness), this study evaluates the effects of the liner’s elastic modulus, the bonding effectiveness at the PE pipe–CIPP liner interface, and the initial ovality of the pipes on the load-bearing capacity. The experimental results reveal that CIPP liners substantially enhance the stiffness and load-bearing capacity of PE pipes, with improvements ranging from 200% to nearly 500% depending on the pipe’s DR value. A novel ring stiffness prediction model is also introduced and validated against the experimental data. This model provides a theoretical framework for understanding the complex interactions at the PE pipe–CIPP liner interface and aids in designing more resilient urban drainage systems.

Development of OPR1000 RCS Hot-leg surge nozzle thermal sleeve remote removal system

The OPR1000-type reactor incorporates seven thermal sleeves (T/S) within the reactor cooling system (RCS) piping line, constructed from Inconel-600 or Inconel-690 material, depending on the power plant. In instances involving T/S made of Inconel-690 material, certain issues were identified either initially or at the commencement of operations. Consequently, the T/S installed on the safety injection nozzle was promptly removed. However, the T/S affixed to the hot-leg surge nozzle remained in operation without removal. Subsequent ultrasonic testing, conducted as part of the scheduled preventive maintenance period, revealed that the T/S associated with the hot-leg surge nozzle in the RCS pipe exhibited protrusions attributable to eccentricity and groove wear. Consequently, the removal of the T/S became imperative. This study delineates the development timeline of a remote system and highlights significant milestones achieved in the removal of the hot-leg surge nozzle T/S during the planned preventive maintenance period.

Performance of Reinforced Concrete Beams with Rectangular Opening in Flexural and Shear Zone

Transverse openings in reinforced concrete beams use to house the utility services like electricity cable, Internet cable, air-conditioning pipe, fire safety pipe line and water-drainage system. These beams opening pipe line system are usually placed underneath the soffit of the beam in term of dead space. This height of dead space that increase the overall building height. Beam opening in the reinforced concrete beams significantly decreases the ultimate load carrying capacity of beam. Transverse beam opening in the web portion of beam produces discontinuities in the usual flow of stresses and that leading stress concentration around the opening region. The importance of this study is to evaluate the performance of reinforced concrete beam with varying size rectangular opening at flexure and shear location ware investigated. A nonlinear finite element analysis was conducted to investigate the effects of different size openings, in terms of ultimate load carrying capacity, Elemental Stresses, load-deflection plot, crack pattern. The work involves investigating performance of different size of small and large rectangular opening. This paper gives new challenges for engineering practice which is in the field of strengthening of concrete structures especially in transverse RC beams with rectangular openings.

Dissolution of Nb(C,N) During Post-weld Heat-Treatment of Electric Resistance Welded X70 Line Pipe

Dissolution of Nb(C,N) During Post-weld Heat-Treatment of Electric Resistance Welded X70 Line Pipe

Testing and analysis of CIPP liner under simulated groundwater pressure

Cured-in-place pipe (CIPP) is commonly used to rehabilitate deteriorated culverts and drainage structures. During installation, factors like corrosion, joint staggering, and insufficient inflation can create an annular gap between the liner and host pipe, potentially leading to buckling failure under external loads. Existing design methods lack experimental evaluation, leading to discrepancies between simulations and monitoring. To address this, an experimental study was conducted using a carefully designed test system to minimize boundary condition influences. Two tests were performed with host pipes of 600 mm and 1000 mm outer diameters. Simulating underground water pressure, elliptical deformation of the CIPP liner was observed until the host pipe’s wall was contacted, with localized arching in non-contact areas. The width of the annular gap (Δd) between the liner and host pipe determined whether hydrostatic buckling occurred before critical buckling. However, the critical buckling pressure could not be accurately predicted by existing buckling models. In response to this issue, an improved model is proposed based on pressure from elliptical deformation and buckling caused by local arching. The experimental results showed that the simulation error ranges from -0.5 % to +1.1 %. Our study provides valuable insights into enhancing CIPP liner buckling resistance and offers a more accurate model for predicting critical buckling pressure, contributing to safer and more reliable CIPP rehabilitation methods.

Thickness optimization of semi-structural CIPP pressure pipe liners: A mathematical modeling approach

This paper introduces a novel mathematical model to optimize the thickness of semi-structural liners in Cured-In-Place-Pipe (CIPP) rehabilitation based on the host pipe holes criterion defined in current standards. The model considers the residual structural mechanical properties of the damaged host pipe, and holes are defined considering the direction, the area, and the perimeter of the host pipe hole, providing a more accurate estimation of the liner behavior. Results indicate potential thickness reductions of 20%–40% for circular holes, while non-circular holes offer even greater optimization possibilities ranging from 40 to 80%. Moreover, a full-scale test was conducted on a reinforced concrete host pipe of DN 400, damaged with three holes 150 mm in diameter. The full-scale test results were used to refine the numerical model employed in developing the mathematical model, ensuring its accuracy and reliability.