Risk management of gas pipeline

Pipeline transportation of gas has the advantages of convenience and low transportation cost, so the best way for gas transportation is pipeline transportation. However, due to the gas’s flammability, flammability and the uncertainty of the potential safety hazards of the pipeline, there are certain risks in the pipeline transportation of gas. To evaluate the risk of pipeline transportation of gas and explore the safety problems that are easy to occur in the process of pipeline transportation of gas, the key is to formulate corresponding measures. In this paper, the characteristics of the gas pipeline and prone to safety problems are discussed, and the existing risks are analyzed and studied.

Background

Current situation of pipeline transportation

With the rapid development of China’s economy, the centralized supply of industrial gas has become a trend. The so-called centralized supply means that the professional industrial gas production enterprises establish a gas supply center in a region for centralized production. The products are transported to several customers in the region through pipelines, and the adjacent regions can be connected by pipelines, So as to form a complete supply network in the main industrial user area. This scientific, economic and efficient supply mode has a history of nearly one hundred years in western countries. It has just sprung up in China. Linde Group, a global gas giant, has built 120 km of nitrogen, oxygen and pipelines in Ningbo, Zhejiang Province, connecting Ningbo Economic and Technological Development Zone, Daxie Development Zone and Ningbo Petrochemical Economic and Technological Development Zone (Zhenhai) into a gas supply network, In addition to supplying gas to large steel and chemical enterprises in Ningbo iron and steel, Formosa Plastics, AkzoNobel and Wanhua, it also supplies gas to small and medium-sized enterprises such as Taijing electronics and keninda. With the rapid development of social economy, gas production industry is more and more developed. Pipeline transportation has the characteristics of low transportation cost and high transportation efficiency, which has been widely used in the supply of industrial gas. However, pipeline transportation also has certain limitations and risks. Although strict measures and management specifications have been adopted in the design and safety management of gas pipelines, and qualified pipes and anti-corrosion materials have been selected in the selection of materials, there are many kinds of conditions that affect the safety of pipeline transportation, such as the operation errors of managers, natural disasters, third-party damage, corrosion prevention and so on Pipeline corrosion and so on for a long time, so it often leads to serious accidents such as leakage and explosion of gas transmission pipeline, which not only causes economic and property losses, but also may cause casualties. The problem of pipeline safety risk management is that the managers don’t know when and where the pipeline accidents will happen and the severity of the consequences caused by the accidents. This uncertainty is the risk that must be faced in pipeline transportation. Although the managers can’t predict the accident of the pipeline, it is necessary and possible to analyze and evaluate the safety risk of the pipeline and take certain measures to reduce the possibility and frequency of the accident, which is to analyze the potential safety hazards that are easy to cause the accident.

Hidden danger of pipeline transportation

Due to the characteristics of industrial gas products and its irreplaceable role, the gas production industry is booming. In industrial production gas, the produced gas often has the characteristics of flammability or combustion supporting, such as oxygen combustion supporting and hydrogen flammability, so it is particularly important to ensure the safety of industrial gas transportation. And in the process of pipeline transportation of gas, due to the flammable and combustion supporting characteristics of gas, the external conditions of the pipeline often lead to accidents. In the production of industrial gas, the most productive gases are oxygen, hydrogen, nitrogen and other gases. It is very important to understand the characteristics of these gases and the accident prone to pipeline transportation safety. In the process of oxygen pipeline transportation, because oxygen has combustion supporting property, it is very important to ensure the safety of oxygen pipeline transportation. With the development of industry, the use of oxygen is also gradually increasing. In the iron and steel industry, oxygen is needed for metal refining, cutting, welding and surface cleaning of steel embryo. The accidents that are easy to occur in the oxygen pipeline are usually combustion, fire and explosion. In the process of pipeline transportation of hydrogen, because hydrogen is a flammable, explosive and toxic gas, we need to be very careful in the process of pipeline transportation of hydrogen. In addition, nitrogen, argon and other gases with large production volume are also included in industrial gases. It is of great significance to understand the characteristics of these gases, assess the risk of pipeline transportation of these gases, establish a hypothetical structure, and predict the accidents that are prone to occur.

Risk assessment of pipeline gas transmission

The risk of gas transmission pipeline refers to the comprehensive degree of the probability of accidents and the consequences of accidents in the process of gas transmission. The risk assessment of gas transmission pipeline is to determine the risk degree of gas transmission pipeline according to the relative risk of gas transmission pipeline, and formulate corresponding preventive measures and safety management measures, Risk assessment management is an effective means to ensure the safety of pipeline gas transmission. The purpose of risk assessment is to analyze and study the risk of pipeline gas transmission, which is an important work in gas industry. The main basis for risk assessment of pipeline gas transmission is the identification of hazard sources, the composition of pipeline gas and the consequence of accidents.

Hazard identification of gas transmission pipeline

The material used in the construction of gas industrial pipeline is usually steel pipe. The pipeline is exposed to the outside for a long time. The long-term erosion of rainwater, the oxidation of oxygen in the air and the interference of external force will cause damage to the pipeline. In the accidents of gas transmission pipeline in gas industry, the most important reason is the rupture of pipeline. Usually, the main factors causing the rupture of pipeline are the third party damage, pipeline material corrosion defect, natural disasters and so on. Once the pipeline is broken, the gas transported in the pipeline will leak. Because most of the gas transported in the pipeline is flammable, once the gas meets the fire source at the leakage point, it will burn. In addition, the continuous emission of gas combustion will form.
When the gas leakage reaches a certain extent, it is likely to lead to gas combustion and explosion. This kind of explosion is less destructive. However, if there are buildings near the leakage pipeline and the gas enters the building after leakage, it is likely to explode in the building space, and this kind of explosion is extremely destructive, It may even cause buildings to collapse. Moreover, the explosion at the leakage point may cause more serious damage to the pipeline and cause more gas leakage, which will eventually lead to extremely serious explosion accidents.

Analysis of composition characteristics of pipeline gas

The risk assessment of pipeline gas risk management in gas industrial production can ensure the safety of pipeline gas. The risk assessment of pipeline gas should first understand the main components and characteristics of pipeline gas. In the gas industrial pipeline, the main gases are oxygen, hydrogen, nitrogen, etc. Oxygen is a colorless, odorless and insoluble gas in water. Its density is slightly higher than that of air. It has the characteristics of supporting combustion. In addition to oxygen, these gases have certain flammability, flammability and toxicity. When the pipeline breaks, the most serious risk is that these poisonous and harmful gases will gradually dissipate in the air, which will not only cause serious pollution to the environment, but also pose a threat and damage to the health of the surrounding people. In addition, the heat generated by the transportation of these gases in the pipeline and the friction of the inner wall of the pipeline will also make the gases react in the pipeline, or even form new chemical products (for example, oxygen and hydrogen will react at high temperature to form water oxygen, and oxygen and nitrogen will react to form nitric oxide and nitrogen dioxide), If the friction temperature is too high, it is likely to cause gas combustion and explosion in the pipeline. In addition, some gases in the pipeline have acid characteristics, which are the main causes of metal corrosion on the inner wall of the pipeline, especially when there is water in the pipeline, these acidic gases are highly corrosive when dissolved in water.

Characteristics of pipeline risk management

Advanced with the times

The establishment of pipeline integrity management system not only standardizes the technology and method of risk identification for new pipelines, but also develops high-definition magnetic flux leakage internal detection equipment for in-service pipelines to detect the corrosion inside pipelines and spiral welds. It completely changed the passive situation that the internal corrosion of the pipeline which has been running for many years is unknown and the exposed problems are difficult to be treated. It realizes the multi angle and all-round risk management of the implementation of source control for the hazard factors of the new pipeline, the hazard identification of the in-service pipeline, the development of pipeline detection, and the comprehensive evaluation and treatment.

Rigorous and scientific

From the whole process of pipeline design, construction and operation, the pipeline hazards are classified and identified, and the identified hazards are analyzed qualitatively and quantitatively.

Clear purpose

Through pipeline detection, hazard identification and risk assessment, effective preventive measures are formulated to reduce pipeline operation risk.

Fine integrity

The specification not only puts forward the identification requirements for the defects of pipeline material itself, but also puts forward comprehensive, detailed and specific identification and evaluation standards for the hidden dangers that may be induced by the geological conditions, geographical environment and social environment of pipeline laying.

Conclusion

Based on the research and analysis of the main causes and potential hazards of pipeline transportation gas accidents in gas industry, the following targeted measures are proposed:

1. The prevention of gas leakage and pipeline leakage is an important part of risk management of gas industry pipeline. Gas leakage accident will lead to fire and explosion and other destructive catastrophic accidents. The most important way to prevent gas leakage is to select good materials in the process of pipeline construction. The construction process should be rigorous, serious and responsible to ensure the firmness of the pipeline. In the process of pipeline application, the management personnel should regularly check whether the pipeline is damaged, and timely repair the damaged part of the pipeline to avoid serious consequences. Gas industry enterprises should also carry out safety education and training for pipeline management staff, improve the actual operation level of operators, strengthen the safety awareness of pipeline management staff, and reduce the number of accidents caused by staff errors.
2. In the process of transporting gas in pipeline, the surrounding of pipeline should be controlled to avoid contact with fire source, the quality of pipeline equipment and the installation of pipeline should be strictly required, and the pipeline management and the implementation of safety measures should be strengthened.

In a word, although the pipeline transportation of gas industry has certain danger and insecurity, the occurrence of gas pipeline accidents can be reduced or even avoided as far as possible by risk assessment and risk management of gas pipeline, analysis of risk sources that are easy to cause accidents, and taking measures to control and manage them. Only in the process of production and transportation of gas, gas industry enterprises strengthen the safety management of transportation, can they avoid the possibility of accidents, so as to promote the development of enterprises.
Author: Mei Feng

Source: China Gas Pipeline Manufacturer – Yaang Pipe Industry Co., Limited (www.epowermetals.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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Reference:

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