Regarding the burial depth and slope of underground oil and sewage lines, is it mandatory to bury them below the permafrost layer?
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As the title suggests: the permafrost layer is about 160 cm thick, while the underground oil and sewage pipelines are buried only at a depth of 80 cm. The slope is approximately 0.3%. The main concern is freezing in winter and the potential rupture of these underground pipelines. Is this in compliance with design standards? Which standard contains this information? Neither SH 3012 nor GB50016 addresses it. Thank you! ! !
Was no heat tracing added? We are in the north, where heat tracing is used along the entire pipeline.
Heat tracing can be used; run the steam line alongside the main line, and if it is long enough, it can be divided into sections.
The buried sections all have a cover plate structure, which is removed and rewelded. The device is also equipped with dual heating systems; this is done to address the difficulties associated with maintenance – one unit is in use while the other serves as a backup, and they switch over in case of leaks. Repairs are carried out during major overhauls. Generally, no problems arise, but without heating, the device can freeze in winter, which may affect production.
SLDI 333C06-2001 \"Specifications for the Clear Height or Burial Depth of Pipelines\" 7. The determination of the burial depth for buried pipelines should be based on the principle that the pipelines shall not be damaged, and factors such as the maximum depth of frozen soil and the groundwater level should also be taken into account. The distance from the top of the pipe to the ground should not be less than 0.5m ； In areas with concrete floors, whether indoors or outdoors, the height of the pipe tops above the floor should not be less than 0.3 m ； The clearance under the passage for mechanical vehicles should not be less than 0.75 m, or protection via sleeves should be used. If there are valves on buried pipelines, valve chambers should be provided. The size of the valve chamber should allow for access for operation and maintenance. The top surface of the chamber walls should be about 100 mm above the ground level, and it should be equipped with a cover. The clearance between the bottom of the chamber and the bottom of the pipes should be no less than 200 mm; for insulated pipes, this clearance should be at least 300 mm. The valve chamber should also have drainage facilities.