【Event】January’s Topic 200904 -- “Gas Transmission Stations in Long-Distance Pipeline Projects: Installation of Cleaning Devices” (Large Prize)
Thread Content
【Event】January’s Topic 200904 – “Gas transmission stations in long-distance pipeline projects: Installation of pigging devices”. Discussion topics include: 1. What are the principles for installing pigging devices in long-distance pipelines? 2. What is the typical spacing between pigging stations? 3. What are the types of pigging devices? 4. How to set up the pigging process? 5. What are the requirements for the layout and installation of the serve and receive cylinders? 6. What are the operating procedures and precautions for pigging operations? 7. Examples of specific project-related experience. Discussion on other related issues. . . Communication requirements: First, list the title of the question ； Provide an explanation for the issue, and present one’s own views and opinions ； The discussion should be supported by evidence, such as provisions in standards and specifications, as well as engineering examples. Next, we will continue with the series of discussions on natural gas long-distance pipeline projects, one topic per day in January. Discussions should be posted as replies here; all responses that participate in the discussion will receive high scores. Those with a certain level of depth may be awarded an additional score of 10–100 points or 1–10 points in terms of appeal, and particularly insightful discussions will receive special rewards. This post was last edited by dreamxy2008 on 2009-4-2 21:51]
Principles for the layout of pipeline pig launcher and receiver devices: (1) For valves through which pigs pass, straight-through ball valves and flat gate valves with guide holes should be used; for valves through which pigs do not pass, ball valves and flat gate valves without guide holes are suitable； (2) The structural length of the pig launcher and receiver should be sufficient to accommodate the passage of pigs or detectors ； (3) A pig passage indicator should be installed 1 km ahead of the pig entering the station, as well as between the receiving cylinder and the main line gate ； A pigging flow diverter should be equipped with a pig passage indicator ； (4) The installation height of the pig receiver and transmitter should be between 0.8 and 1.3 m, with a maximum of 1.5 m ； (5) The quick-opening blind flanges on the pig launcher and receiver should not be positioned directly facing residential areas or building complexes that are within a distance of 60 meters or less ； (6) A sludge tank should be installed under the blind flange of the pig receiving and sending cylinder. A sludge tank should be installed within the pigging area. The contaminated oil generated during pigging operations should be collected and treated centrally; it must not be discharged arbitrarily ； (7) Pigging should be carried out using a closed pigging process ； (8) When the emissions during natural gas line cleaning contain Class A and Class B liquids, separation equipment should be installed to recover the condensate, with the gas being released to a safe area.
1. Principles for installing pigging devices in long-distance pipelines: Pigging devices are necessary for pipelines carrying crude oil, refined oil, natural gas, and other similar substances. The cleaning of crude oil pipelines is primarily aimed at removing the wax that forms as a result of crude oil degradation during production and operation. In contrast, since refined oil and natural gas have cleaner compositions, cleaning devices are usually used for assisting with cleaning and purging before operations begin, as well as for intelligent cleaning tasks during the later stages of operation. 2. Spacing between pigging stations: There are no domestic standards governing the placement of pigging stations; for crude oil pipelines, the density of such stations should be the highest. Generally, pigging stations are built together with other types of facilities. There are relatively few pigging stations installed along the entire length of refined oil pipelines; for a 600-kilometer pipeline that has been built in China, only one pigging station was installed at 150 kilometers mark. 3. Type of pig: With technological advancements, pigs have gradually moved beyond their most basic cleaning functions and have come to incorporate features such as intelligent monitoring. For long-distance pipelines, barrel-type ball receivers and senders are still widely used in China; however, this year cleaning valves have also been applied to short-distance, small-diameter pipelines, with good results as well. 4. Setting of the pigging process: The main process allows flow to enter the station directly, while the pigging process is activated through valve switching, enabling the medium to enter the station after ball sending and receiving. 5. Requirements for the installation of ball receiving and sending cylinders: They must be designed to facilitate operation by workers and ensure safety; safety valves should be installed on these cylinders, and quick-acting blind flanges must not be positioned in areas where people may be present. 6. Operating procedures and precautions for pigging operations: For pigs with larger diameters, receiving and sending devices should also be installed to reduce the workload on workers.
1 Cleaning facilities should be located within the gas transmission station. 2 The cleaning process should employ a closed-system cleaning method that does not interrupt gas flow. 3 Indicators for detecting the passage of cleaning devices should be installed on the pipelines entering and leaving the station; indicators should also be installed on the pipelines outside the station as required by automated cleaning operations, with the signal from these indicators being transmitted to the inside of the station. 4 The structure of the cleaning cylinders and receiving cylinders should meet the requirements for allowing the passage of cleaning devices or probes. The design of the pig launcher and receiver, as well as the quick-acting blind flanges, shall comply with the provisions of the current standards **\"Technical Specifications for the Design of Pigging Equipment\" SY/T0533 and \"Quick-Acting Blind Flanges\" SY/T0556. The quick-acting blind flanges on the pig launcher and receiver should not be positioned directly facing residential areas or building complexes that are within a distance of 60 meters or less. When site conditions prevent meeting the above requirements, appropriate safety measures should be taken. 5 The waste removed during cleaning operations should be collected and disposed of properly; it must not be discharged carelessly
I’m sorry, but almost all of the content above is correct. I’ll rearrange the layout again; these are all the exact words from GB50251: 1. Pigging facilities should preferably be located within gas transmission stations； 2. The pigging process should adopt a gas-free, sealed pigging procedure ； 3. The pig passage indicator should be installed on the pipeline sections at the inlet and outlet of the station. Indicators should also be installed on the pipelines outside the station as required for automated pig operation, and the indication signals should be transmitted to inside the station ； 4. The structure of the pig receiving and sending cylinders shall meet the requirements for passing pigs or plug testers. The design of the pig receiver and transmitter as well as the quick-opening blind flanges shall comply with the provisions of the current standards **\"Technical Specifications for the Design of Pigging Equipment\" SY/T0533 and \"Quick-Opening Blind Flanges\" SY/T0556** ； 5. The quick-release blind flanges on the pig launcher and receiver should not be positioned directly facing residential areas or buildings/structures within a distance of 60 meters or less. When site conditions prevent meeting the above requirements, corresponding safety measures should be taken ； 6. The waste removed during pigging operations must be collected and disposed of properly; it shall not be discharged arbitrarily.
One additional point: a balance valve should be installed on the serving cylinder, while it is not necessary to have one on the receiving cylinder. At the same time, two pressure gauges with different ranges should be installed on the ball receiving and sending cylinders.
May I ask, are pressure gauges with different ranges necessary? How to determine the size range of the scale? I’ve never done this before; I hope friends with experience can offer some guidance.