Our Telecommunication Tower are made from quality sheet through bending,
forming, automatic welding and hot galvanization. We can reach one-run
machining length of 14m and can bend sheet of thickness up to 45mm. We
adopt advanced welding procedures, automatically weld main joints and
reach rank-II welding quality.
We have supplied 2400ton 132kV and 220kV transmission line steel pole to WAPDA. Pakistan on 2008 and have supplied 1200ton 138kV transmission line steel pole to Davao light, Philippines on 2009.
Telecommunication Tower, Telecommunication Steel Tower, Telecom Steel Tower, Telecom Steel Mono Tower Jiangsu Xinjinlei Steel Industry Co., Ltd. , https://www.jinleisteeltower.com
Design and Research on Ball Valve Structure of Long Distance Pipeline
I. Overview To make the economy in western China develop rapidly, the state has made major decisions on the development of the western region. The development of Xinjiang's oil and natural gas resources is one of the major measures for developing the western region. For the oil and gas resources in the west to be fully utilized, the only way is to send the oil and gas to the eastern region of our country through the pipeline. To this end, the state will construct the "West-East Gas Pipeline" pipeline project, in which the main pipeline will be laid down and the Lunnan gas field in the Tarim and the Shanghai area will be opened to the east, covering a total length of 4,200 km. Pipeline transportation has become one of the main ways of transporting materials in the contemporary world. Utilizing long-distance pipelines to transport oil, gas and other resources has become the most important means of energy transmission in the world today. The world's major oil and gas producing and consuming countries are extensive use of long-distance pipeline to solve the transportation of oil and gas resources, of which more than 95% of natural gas pipeline using the pipeline. According to statistics, at present, the total length of long-distance oil and gas transmission pipelines in the world has exceeded 2.6 million kilometers. Among them, the total length of natural gas transmission pipelines is about 1.4 million kilometers, accounting for more than one half of the total pipeline length. From abroad's experience in construction and transportation, it is more economical to build a large-diameter pipeline than to build several small-diameter pipelines under the same transportation capacity. In addition, it is more economical to increase the medium transportation pressure within a certain range. Similarly, Can increase efficiency. Therefore, the West-East Pipeline taken diameter: nominal diameter DN = 1000mm, nominal pressure PN = 10.0MPa. Such parameters in our previous gas pipeline network is never. The long-distance West-East gas pipeline in our country runs long distances. The pipeline passes through the deserts, rainforests, swamps, mountains, rivers (the Yangtze River, the Yellow River) and the plains. The climate in this area is harsh. The ambient temperature varies from -30oC to +80 oC with poor environmental conditions. therefore. The requirements of long-distance pipeline valves are much higher than the requirements of common valves, requiring long-distance pipeline valves with higher reliability, higher sealing, higher strength to ensure long-distance pipeline safe and reliable operation. Second, the development of pipeline ball valve Long-distance pipeline development, after decades of initial size in our country, especially the development of pipeline ball valve, the current pipeline pipeline valve on the domestic application, the parameters have reached PN6. 4MPa, DN1000mm, but with the required parameters of the West-East Gas Pipeline project, there is still some distance, in addition, the pipeline ball valve emergency shut-off device, the country can not produce. In addition, all-welded ball valve, there is no domestic product history. Third, the standard pipeline valve API 6D pipeline valve fire test API 6FA valve API 607 ​​soft seal and 90o steering valve fire test API 598 valve inspection and testing ANSI B 16.34 flange, thread and welded end valve JB / T 7745 Pipeline Ball Valve IV. Characteristics and Requirements of Pipeline Ball Valve In long-distance pipeline, it is required to cut off line valve-pipeline ball valve can control the medium in the pipeline, have the function of switch, change the medium flow direction and prevent reverse flow, send or clean the ball through pipeline to prevent Accident, automatic, emergency cut off, closed or open the pipeline. 4.1 reliable sealing performance Long-distance pipeline can only be patrolled or patrol regularly, and sometimes through the inaccessible mountains, deserts, grasslands and earthquakes and other regions. Small leaks will result in the loss of a large number of media, waste of energy, especially in the West-East Gas Pipeline Project, the sealing of natural gas pipeline is more important, in addition, also requires the sealing performance of emergency grease. 4.2 Life expectancy Long pipeline once put into operation, within a few years or even decades do not allow to stop running, the longer the operation the better, natural gas is facing large users, is a large factory, business of raw materials or energy, do not allow A moment of the gate, therefore, requires the key components such as the valve seat has a long life. 4.3 pipeline valve of high strength, anti-external security West-East Gas Pipeline project, the pressure of the pipeline ball valve up to 10.0MPa. Caliber 1000mm. In addition, due to complicated external forces such as thermal expansion and contraction, equipment vibration, earthquake disaster and foundation change, the valve is often subjected to tension and bending compression in the pipeline And other comprehensive stress, to ensure the normal use of the valve, you must have sufficient strength. 4.4 pipeline valve should be resistant to corrosion due to natural gas containing hydrogen sulfide, it can react with iron to form iron sulfide, corrosion valves, wear corrosion machinery, pipeline valves should be made of corrosion-resistant materials. 4.5 High degree of automation The control of the line ball valve is in the central control room, a long distance, should be able to implement long-distance control or remote control, and emergency shutdown in case of accident. Turn-off time required to reach 15 seconds or so, in the normal operation of the pipeline, may not move within a few years, once the action must be accurate and reliable. 4.6 Pipeline valve requirements Light weight, compact structure, full diameter In order to ensure the valve can be installed in complex field, buried requirements, easy maintenance, requiring the valve light weight, compact structure, and is full diameter, to facilitate the normal operation of the pipeline When able to pigging. Fifth, the design and research The main technical parameters of pipeline ball valve: Nominal pressure PN = 10.0MPa Nominal through DN = 1000mm Actual through D = 1016mm Environmental temperature limit -36oC - +80 oC Medium: natural gas (including hydrogen sulfide and carbon dioxide) Time: Close <15 seconds, open = 600 seconds According to the requirements of the use and standards, as well as the long-distance pipeline valve requirements, combined with the technical parameters of the pipeline ball valve, we made the following design and study: 5.1 All-welded pipeline ball valve Of the leakage, improve the anti-deformation ability of the valve to reduce weight, the need to use all-forged welding structure. Forged welding structure, using forged valve body, welded after assembly, changing the casting, bolting structure in the past, there will be no leakage of the valve body; relative to the casting, the wall thickness of the forging can Thinning and high strength, eliminating the flange and dozens of pairs of bolts on the connection, greatly reduce the weight, according to the test, will reduce the weight of a quarter. 5.2 Sealing Structure The sealing structure is the key design of the sealing performance of the ball valve. It provides a good sealing structure and directly affects the service life of the ball valve. According to the research, we provide the following structures that meet the actual requirements: 5.2.1. Double Piston Effect Valve Seat Double Piston Seat Valve Valve Seat has the basic principle that there are two seat valve seal, if the upstream seat is damaged, the medium into the cavity, and the pressure in the cavity can still make the downstream seat to seal. Therefore, when the cavity has pressure, the media force can make the valve seat to the ball, to seal the purpose. 5.2.2. Double Seal To seal the valve more effectively, the structure uses a double seal structure, a PTFE sealed soft seal. Coupled with a metal hard seal, the metal seal can also function if there is a problem with the soft seal. At the same time, the design of the metal hard seal or the fireproof structure is that the metal hard seal can be sealed when the soft seal is burnt by fire. 5.2.3. Emergency Grease Seal If the seal surface is damaged by foreign matter or other reasons, the sealant filling system in the valve seat provides a quick and easy way to recover a tight shut-off. Fill sealing grease to seal. In addition, the filling system can also be used in the sealing area of ​​the valve seat in the periodic situation. At the same time, also added in the stem seal emergency grease seal supplement. 5.3 Anti-static, fireproof structure Standard requirements of the ball valve must have anti-static, fireproof structure, the valve in the sphere, stem and valve body between the electrostatic structure set in the ring fire structure, in the event of a fire, the metal ring is still Can be sealed, the structure shown in Figure 1: 5.4 emergency shut-off device In the event of a pipeline accident, requiring the accident at both ends of the ball valve emergency shutdown, the general requirements within 15 seconds to close both ends of the valve, or in a shorter period of time At present, most of the valve manufacturers choose the emergency shut-off device of gas-liquid linkage abroad. The device directly utilizes the pipeline transportation medium and utilizes the pressure of the medium to sense the accident signal by the induction device or the command of the main control room Control the valve to achieve the purpose of emergency shut-off valve. 5.5 Fixed ball structure In order to reduce the media stress on the ball and the stem caused by bending stress, the valve stem and the ball connection is designed as a segmented structure to avoid the media pressure directly on the stem, resulting in the difficulty of the valve switch, the other to increase Sphere support cross-sectional area, improve the rigidity of the ball. In summary, to take the above characteristics of several programs to meet the standards of the valve requirements, but also can meet the needs of the project. Sixth, the development trend of pipeline ball valve In recent years, with the rapid development of long-distance pipeline, pipeline valve as one of the emergency cut-off valve, the development speed is very fast, mainly in the following aspects of the development trend: 6.1 large, high Parameters At present, the pipeline valve has developed a large nominal pressure PN = 14.0MPa, DN = 1400mm, large, high parameters will bring greater economic benefits to the conveyor. 6.2 high-strength corrosion-resistant materials Valve size increases, the pressure increases, the urgent need to study the new high-strength corrosion-resistant forging material to meet the growing needs of the valve size. 6.3 Multi-Sealing Structure To ensure the sealing of the valve, a multi-composite sealing structure is being studied to ensure that the valve can be used for a long enough service life of up to 50 years. 6.4 High reliability and quick shut-off Emergency cut-off ball valve, in the gas pipeline for a long time out of the open state, and sometimes do not move for 10 years, but once the action, we must be accurate and reliable, to ensure greater reliability, and be able to Closer shut down in less time. 6.5 A higher degree of automation Urgent cut off the ball valve, can perceive the occurrence of the accident, automatically shut down, longer sensing distance. VII Conclusion In the long-distance pipeline, has been more widely used, the use of the above design structure, to meet the long-distance pipeline requirements. About the author: Huang Mingya, male, born in 1959, director of Hefei General Machinery Research Institute branch of the valve, professor-level senior engineer, mainly engaged in the valve standard research, and valve new product research work.