Routine Maintenance and Fault Analysis of Pipeline

A pressure pipeline is a common equipment for conveying liquid and gas, which is widely used in production and life. A pressure pipeline exerts a certain pressure on the material in the pipeline to realize the material flow in the pipeline, and then realize the transportation of liquid or gas. In pressure pipeline engineering, the valve must be used to control the pressure, flow rate and opening and closing of the pipeline, which is directly related to the operation safety of the pressure pipeline. Most of the valves used in pressure pipeline engineering have complex structures, and it is easy to have problems in valve assembly or connection with pipelines. Moreover, there are many kinds of common valves in the market. In order to meet different requirements, we should choose the appropriate valves. Inappropriate selection of pressure pipeline valves will affect the safety of pipeline operation. Therefore, when carrying out pressure pipeline engineering or maintenance, the emphasis is on the selection and maintenance of valves, and troubleshooting inspection and maintenance of valves can ensure the safety of pipelines and avoid safety accidents.
 
Common faults of pressure pipeline valves
 
The quality of pressure pipeline valves is unqualified.
Valve failures caused by valve quality problems account for a large part of the total number of failures. At present, China's petrochemical industry is developing rapidly, and the construction of pressure pipeline projects is increasing day by day. In order to quickly seize the market and make profits, many manufacturers of pressure pipeline parts have shown signs of emphasizing output but neglecting quality. According to different requirements, pressure pipeline valves can be divided into several categories and dozens of small categories. When constructing pressure pipeline projects or commissioning before production, strict quality inspection of each valve is required, which leads to a significant increase in engineering cost. In order to reduce costs and increase profits, some enterprises neglect the quality of valves when selecting them. These valves with poor quality may not cause major problems in the short term when they are used in pressure pipeline projects, but as the pressure pipeline is used longer, pressure changes and liquid corrosion will lead to valve damage, resulting in valve loosening, leakage or more serious consequences.
 
Unqualified installation of pressure pipeline valves
The installation of pressure pipeline valves needs to follow national standards, which is highly technical work. In pressure pipeline engineering, valve installation problems often occur due to the lack of technical skills or careless work of installers. For example, the pressure pipeline is long, different valves need to be installed in different sections, and the valves are selected or installed incorrectly due to the negligence of installers. Pressure pipeline valves are also easily affected by the external environment. The external environment's temperature, humidity and other factors will interfere with the pressure in the pipeline, making the operation of the pressure pipeline have potential safety hazards. When installing pressure valves, different measures should be taken according to different environments, so as to eliminate the influence of the external environment on valve installation and ensure valve function and safety in use.
 
The operation of pressure pipeline valves is not standard.
The valve failure of the pressure pipeline caused by the operator's improper operation is also one of the common causes of valve failure. Operators fail to follow the steps and sequences required by safety operation regulations when opening and closing valves or regulating pressure, which leads to the occurrence of phenomena such as forgetting to close valves, lax closing of valves, wrong closing sequence of valves, etc., which affects the normal operation of pressure pipelines, changes the pressure in pressure pipelines and causes potential safety hazards or safety accidents. In addition, when the pressure pipeline valve is operated, it is necessary to check the working condition of the valve and find the valve failure in time. If the valve is not inspected during operation, it may cause the valve to be damaged or the valve to be closed loosely, resulting in safety accidents.
 
Pressure pipeline valve maintenance is not timely.
In order to ensure the normal operation of the pressure pipeline, the valves in the pressure pipeline need regular overhaul and maintenance, so that the problems existing in the valves can be found in time. At present, the valve detection methods are: one is to detect the pressure change in the pressure pipeline with the help of instruments, the other is to detect whether there is a crack in the pressure pipeline valve, and the cleaning and cleaning of the proxy pipeline valve is often neglected. In particular, the oil pipeline is affected by oil pollution, which often accumulates impurities at the valve position, affecting the normal opening and closing of the valve, and resulting in potential safety hazards. Therefore, in the process of inspection, it is necessary to timely replace the valve found in the problem, so as to avoid a bigger safety accident.
 
Solutions to the troubles of pressure pipes and valves
 
To ensure the quality of pressure pipeline valves, it is necessary to start with the selection of valves and strictly control the quality. Before the construction of pressure pipeline engineering, the selection and inspection of valves should be carried out in strict accordance with national standards and engineering design requirements: the products of manufacturers with corresponding production qualifications should be selected, and the products with three no's should be rejected. When purchasing products, purchase contracts or agreements should be signed, and clear requirements should be made for product quality and safety. In case of safety accidents, relevant responsible persons can be held accountable. Check whether the indexes of the purchased valves meet the requirements, such as strength, service life, extreme pressure, opening and closing times, etc. Professional technicians or testing institutions should be selected for valve testing, and the inspection results should be made into technical filing documents. Only the valves that pass the inspection are allowed to enter the installation stage of pressure pipeline engineering.
 
Standardize the installation of pressure pipeline valves.
Pressure pipeline valves should be installed in strict accordance with national standards and safe operation procedures, and valve installers should have skilled installation techniques and strict safety awareness to ensure the normative requirements of valve installation. Before installing the valve, the installation personnel should check the type and model of the valve based on the construction drawings, so as to prevent the wrong installation. According to the change of installation environment, choose appropriate installation methods and measures to avoid valve installation problems caused by temperature change or humidity change: when the outside temperature is high, take measures to reduce the temperature of the valve, and adjust the tightness of the valve to avoid excessive internal pressure, resulting in valve damage; When the temperature is low, keep the valve warm to prevent the valve from freezing; Pay attention to the rust prevention of the valve when the humidity is high. The selection of valve installation method should be adapted to the external environment, so as to ensure the smooth installation of the valve and the safety of the pressure pipeline.
 
Operate the pressure pipeline valve according to the standard.
The operation of valves in pressure pipelines has strict operating rules, and operators should strictly follow the operating rules when operating valves in pressure pipelines. The valve operators should be trained in safety operation procedures, so that the valve operators have a corresponding common sense of operation and safety awareness; When operating the valve, it is necessary to strictly abide by the steps and sequence of the operating rules, prevent illegal operation, and prohibit other irrelevant personnel from operating the valve. After the valve operator operates the pipeline valve, he should check the valve status after operation in time, and fill in the valve operation record sheet to ensure that the valve is in a safe operating state; When problems are found, they should be reported in time, and emergency treatment should be completed within the specified time to ensure the safe operation of the pressure pipeline.
 
Pay attention to the maintenance of pressure pipeline valves.
In order to ensure the long-term safe and stable operation of the pressure pipeline, prolong the service life of the valve and save the construction cost of the pressure pipeline project, it is necessary to pay more attention to the maintenance of the valve. Special maintenance personnel should be set up to regularly check the pressure pipeline valves, check whether the running state, pressure and various functions of the valves are in good condition and whether there are any sundries around the valves that affect the operation of the valves. Adopt advanced technology to monitor the running state of the valve, and realize online detection and control. Through the automatic and intelligent control device, the real-time monitoring of the pipeline operating pressure and the state detection and control of the valve can be well realized, which not only saves a lot of manpower and material resources but also finds the faults and problems in the operation of the valve in time, thus ensuring the safety of the pressure pipeline.
 
Install necessary safety protection devices.
Pressure pipeline leakage will cause serious safety accidents. In order to reduce the impact of safety accidents, necessary safety devices should be installed on pressure pipeline valves. Select the appropriate safety device according to the type of pipeline leakage: if the pipeline is prone to internal leakage, you can choose a valve with a barrier device, which can minimize the leakage of material inside the pipeline when internal leakage occurs; If the pipeline is prone to leakage, the valve with closed protective film can be selected, which can minimize the leakage when the pipeline leaks. Fire protection devices should be set around the pressure pipeline valves, and the valve operators should be familiar with the operation process of the fire protection devices. In case of fire, appropriate measures should be taken to deal with it the first time to avoid serious safety accidents.
 
Conclusion
The safe operation of the pressure pipeline is closely related to the daily maintenance and failure of the valve. We must attach great importance to the analysis and countermeasure research of the valve failure, so as to ensure the safe operation of the pressure pipeline at all times, prevent problems before they happen, and improve the safety of the pipeline valves.