PE pipes are mainly divided into two types of construction methods: slotted laying and trenchless construction in municipal water supply and drainage projects. Today, PE pipe manufacturers mainly explain the construction methods of slotted laying.
(1) First, pay attention to the specifications of pipeline laying according to relevant regulations during construction, and conduct inspections in accordance with product standards, and eliminate pipes that do not meet the standards. If the pipeline is laid under the roadway, the thickness of the covering soil on the top of the pipe should not be less than 0.7 meters. If you need to cross obstacles, you need to set up a protective casing made of steel bars. When laying the pipeline, it should be constructed in a straight line. If it is necessary to use a flexible interface for laying with a broken line, the angle of the longitudinal axis of the connected pipeline should not be greater than 2°. When the buried depth of the pipeline is lower than the bottom surface of the foundation of the building, the pipeline should not be laid in the compression area of the foundation diffusion angle under the foundation of the building. When the groundwater level is higher than the elevation of the trench bottom, measures to lower the groundwater level should be taken during construction to prevent the trench from becoming unstable. freeze.
(2) According to the pressure of the external environment, PE pipes with different stiffness should be selected.
(3) When carrying out trench excavation, the width of the groove bottom of the PE pipe trench should be reasonably determined first, in accordance with the construction regulations, so as to facilitate manual operation. During the construction process, no over-digging of trenches is allowed. If over-digging is done inadvertently, it is advisable to use natural graded sand and gravel for landfill. The particle size of the sand and gravel for landfill should be between 10mm and 15mm, or the maximum particle size should be less than 40mm.
(4) The pipeline foundation adopts sand cushion foundation, and grooves should be reserved at the interface to facilitate the operation of the interface. After the construction of the interface is completed, it should be filled with sand. For the general soil section, only a layer of sand cushion with a thickness of 0.1M needs to be laid. If it is a soft soil foundation and the bottom of the groove is below the groundwater table, a layer of sand and gravel foundation with a thickness of not less than 500px should be laid.
(5) During the installation and construction of the down pipe, the groove width, groove depth, foundation surface elevation, inspection well, etc. after grooving should be strictly inspected to ensure that the operation items meet the construction requirements and regulations before proceeding to the next step. , in order to improve the construction quality.
(6) After the inspection is completed, the next step is to connect and install the PE pipe. The manual installation method should be used for non-metallic rope sliding pipes, so that the pipes can be placed on the gravel foundation stably. The installation order of the socket and socket pipe should generally be in the direction of the water flow of the socket and the direction of the water flow of the socket, and the order of installation from low to high should be carried out. When the interface process is carried out, first clean the ports on both sides and then apply lubricating oil. After painting, align the center line and wait for connection. The connection between the pipeline and the inspection well can be connected by an intermediary layer. The pipes in the connecting part of the two are pre-made with plastic adhesive and coarse sand that can be well bonded to the pipe as an intermediary layer, and then connected with 1:2.5 cement. The mortar is built into the inspection well wall to make the connection between the well and the pipe dense, the bottom hole flow groove and the inner wall of the pipe are smoothly joined, and the nozzle of the pipe is flush with the inner wall of the well.
(7) After the PE pipeline is installed, it should be strictly inspected. If the inspection is qualified, the trench backfilling will begin. When the trench is backfilled, the range from the bottom of the pipe to the top of the pipe within 1750px must be manually backfilled, and the mechanical backfill can only be used if it is more than 1750px. . When backfilling, make sure that there is no debris in the trench. In addition, the compaction degree of backfilling should not be less than 95% for the thoracic cavity, not less than 80% for the top 500mm of the tube, and not less than 90% for other parts. Attention should also be paid to the selection of compaction equipment to avoid damage to the pipeline structure during construction.
