The maintenance of communication, monitoring, power and other equipment attached to pipelines is not a specific task of pipeline maintenance. Generally speaking, pipeline maintenance refers to cleaning, line maintenance, and emergency repair of pipelines.
The main measures to maintain and restore the normal operation of transportation pipelines and their equipment include regular and temporary pipeline maintenance and repair.
pigging
Remove accumulated condensate, wax, mechanical impurities, corrosion products such as iron sulfide and accumulated water in oil and gas pipelines to restore or improve pipeline transportation efficiency. These substances adhere to the pipe wall or deposit under the pipe, reducing the cross-sectional area inside the pipeline and corroding the inner surface of the pipeline, increasing the energy consumption of oil and gas transportation. Pipe cleaning mainly uses pipe cleaners. Some pipe cleaners are equipped with various instruments to measure pipe wall thickness, internal corrosion, pipeline deformation, and positional settlement. The commonly used cleaning tools include spherical cleaning tools, skin bowl cleaning tools, and soft cleaning tools.
Spherical pipe cleaner
Also known as a cleaning ball, it is commonly used to clear accumulated water in pipelines and condensate in gas pipelines. It is also used for cleaning the inside of pipelines after construction and before production, as well as for isolation during the sequential transportation of oil products. The outer diameter of the cleaning ball is generally 2% larger than the inner diameter of the pipeline, which is called interference fit. Before placing the cleaning ball into the pipeline, it is necessary to fill the ball with water to expand it, so that the cleaning ball can form a ring-shaped contact surface with the pipe wall when running inside the pipeline, achieving good sealing and cleaning effect.
The operation of the pipeline cleaner relies on the pressure difference formed before and after it, which is generally 0.3~0.5 kgf/cm during operation. The pressure difference required for the operation of the cleaning ball is smaller than that of other forms of cleaning devices. After long-distance operation and wear, the diameter of the cleaning ball will decrease, and its sealing performance and cleaning effect will also decrease. The method of refilling with water and increasing pressure can be used to restore the diameter of the ball. A cleaning ball made of durable plastic with a wall thickness of 50 millimeters can travel about 2000 kilometers. The cleaning ball has strong adaptability and can pass through bends with small curvature radii; And it can be positioned for sending and receiving by utilizing the gravity of the ball. The disadvantage of using a cleaning ball is that it has poor effectiveness in removing solid substances such as wax and rust inside the pipe, is expensive, and it is difficult to install testing instruments on the ball.
Underground pipeline leakage detection
Leather bowl type pipe cleaner
The leather bowl is fixed on the shaft of the pipe cleaner; When several leather bowls are connected together, flexible connections are used between the shafts to increase the ability to pass through bends with smaller curvature radii. The length of this type of pipe cleaner is generally not less than 1.5 times the inner diameter of the pipeline. To ensure a tight fit between the cup and the pipe wall, the diameter of the cup should be 3 millimeters larger than the inner diameter of the pipe. Steel wire brushes or scrapers can also be installed between the cups to clean and scrape welding slag, rust, wax blocks, etc. This type of pipe cleaner is also known as a mechanical pipe cleaner. The leather bowl type pipe cleaner has a good cleaning effect, is inexpensive, can replace easily damaged parts, and is also easy to install various testing instruments. When the pipeline is first put into operation with a cleaning device, the cleaning device may get stuck inside the pipe. In order to find the stuck position, a tracer that can emit radio waves can be placed in the cleaning device. The signal it emits can pass through the steel pipe and soil layer, so that the detector can accurately find the position of the cleaning device.
Including inspecting pipeline corrosion and anti-corrosion conditions; Check for oil leakage points in the pipeline; Check the condition of valves along the line; Check the loss of hydraulic structures and covering soil layers along the line; Check for signs of damage, etc. Once faults are detected in the pipeline and equipment, they should be repaired or updated in a timely manner.
The pipeline route is long and may be damaged by human and natural disasters at any time. Therefore, regular patrols and maintenance work should be carried out. In addition, there is a dedicated pipeline maintenance team equipped with necessary mobile equipment, earthwork construction machinery, welding and sealing equipment, as well as communication tools, in order to be ready for emergency repairs at any time.
Underground pipeline leakage detection reminds you of pipeline anti-corrosion inspection
Daily anti-corrosion inspections include: regularly testing the protective potential along the pipeline; Use an anti-corrosion layer detector to check the integrity of the pipeline anti-corrosion layer on the ground, and promptly excavate and repair any damages found. The inspection of corrosion inside old pipelines is a complex task, often carried out using a cup type pipe cleaner equipped with testing instruments. The testing instruments include magnetic flaw detectors for detecting internal corrosion and ultrasonic thickness gauges for detecting pipe wall thickness. The running distance is calculated using the number of rotations of the support wheel, and all tested parameters are converted into signals and recorded on a magnetic tape. After the inspection is completed, the magnetic tape can be interpreted by the computer to indicate the degree and location of corrosion in the pipeline.
Underground pipeline leak detection reminds you of pipeline leak inspection
Mainly relying on patrol personnel for inspection. In order to ensure the safety of residents and enterprises along the route, various countries have formulated safety technical specifications for oil and gas pipelines, which are strictly supervised and implemented by relevant departments. If there is a leak in the pipeline, immediately report to the competent department and inspect the cause of the accident on site.
Pipeline coverage and maintenance
Rainstorm and flood will cause the loss of pipeline covering soil and damage to the embankment, resulting in exposed, suspended and even broken underwater crossing pipelines. These situations were mainly discovered by patrol personnel. Patrol personnel usually use ground walking or aerial flying to patrol the line. Pipeline maintenance work must be carried out according to the detailed completion drawings of the pipeline engineering.
