High-pressure steel pipes are used to manufacture carbon steel, alloy steel and stainless steel seamless pipes of steel pressure vessels and pipeline quality.


Manufacturing methods are divided into hot rolling (extrusion, expansion) and cold drawing (rolling). The diameter of hot rolled (extruded, expanded) steel pipe ranges from 22 mm to 530 mm, and the wall thickness ranges from 2.0 mm to 70 mm. The diameter of cold drawn (rolled) steel pipe ranges from 10 mm to 108 mm, and the wall thickness ranges from 2.0 mm to 13 mm.


High-pressure steel pipe has good mechanical properties at room temperature and high temperature, strict quality control, and is suitable for all kinds of workplaces under high pressure. High pressure boiler steel pipe is mainly used for field, high pressure fuel pipe, fertilizer equipment and pipeline.


The installation requirements of high pressure pipelines are similar to those of medium and low pressure pipelines, but the requirements are stricter and the regulations are stricter. Therefore, besides the requirements, the installation requirements of low pressure pipelines should also be carried out according to the following requirements.


The high-pressure pipes, fittings, fasteners and valves for installation must pass the test and be accompanied by corresponding technical documents. They should be properly transported to the site, clearly marked and neatly placed. Before installation, the inside and outside surfaces should be wiped clean, and check whether there are foreign bodies in the passage, whether smooth. Check whether the roughness of nozzle and gasket sealing surface meets the requirements, and do not affect the sealing performance of the sealing surface scratches (especially radial scratches), spots and other defects. Additionally, oil or butter or white vaseline protection is provided for degreasing pipes, nozzle and gasket sealing surface coatings. The high-pressure pipe shall be inspected and approved by the end of the threaded part. In addition to the degreasing pipe, it shall be painted to protect the transfer agent graphite or molybdenum disulfide grease.


Official fixed pipe racks and high-pressure pipes should be used in pipeline installation, and protective sleeves should be installed in the design requirements of pipeline joints. Installation of exposed high-pressure flange end screw chamfering. When installing gaskets, do not use steel wire immersion, first spray nozzle and cushion with butter, soft metal high-pressure gaskets should be accurately placed in the sealed shell. Flange bolts should be symmetrically tightened evenly and not excessively. After tightening, the two concentric flanges should be parallel, the exposed nuts should be 2 to 3 buckles, at least two buttons, and each bolt should be exposed uniformly. In the installation process, do not use strong pulling force, strong driving force, distortion or modification of strong seals to make up for manufacturing thickness or installation error. Pipeline installation can not be completed continuously. Opening nozzles should be closed in time.  Instrument sampling points on pipeline components should be installed with pipelines.