Quality Inspection for A 106 Gr. B Seamless Pipe - S355j0h seamless steel pipe quality assurance – Weichuan

en10216-1 specification: φ 10.2~ φ 356*1.6mm~20.0mm

European standard: en10216-2 specification: φ 10.2~ φ 168.2*1.6mm~20.0mm

High pressure steel pipe has good comprehensive mechanical properties at room temperature and high temperature and strict quality control. It is suitable for various working occasions under high pressure. High pressure steel pipes are mainly used in the fields of boilers, high pressure oil pipes of diesel engines, chemical fertilizer equipment and pipelines.

The requirements for the installation of high-pressure pipelines are similar to those for the installation of medium and low-pressure pipelines, but the requirements are higher and the regulations are stricter. Therefore, in addition to meeting the installation requirements of medium and low-pressure pipelines, the following requirements shall be followed.

The high-pressure pipe sections, pipe fittings, fasteners and valves used for installation must pass the inspection and be attached with corresponding technical supporting documents. After they are transported to the site, they shall be properly kept, marked and placed neatly. Before installation, the inner and outer surfaces shall be wiped clean, and the inner channel shall be checked for foreign matters and smoothness. Check whether the roughness of the nozzle sealing surface and gasket meets the requirements. There shall be no scratches (especially radial scratches), spots and other defects affecting the sealing performance on the sealing surface. Except for the pipes with degreasing requirements, the nozzle sealing surface and gasket shall be coated with engine oil or butter or white vaseline for protection. The threaded part of the pipe end of the qualified high-pressure pipe shall be coated with molybdenum disulfide grease or graphite engine oil for protection, except for the pipes that are degreased as specified.

During pipeline installation, the formal pipe rack shall be used for fixation, and the protective casing shall be installed on the pipe rack in contact with high-pressure pipes and fittings according to the design requirements. When installing the high-pressure flange, the chamfer of the pipe end thread shall be exposed. When installing the sealing gasket, do not hang it with metal wire. Grease shall be applied to the pipe orifice and gasket in advance, and the soft metal high-pressure gasket shall be accurately placed in the sealing seat. The flange bolts shall be tightened symmetrically and evenly without excessive. After the bolts are tightened, the two flanges shall be parallel and concentric. The threads exposed outside the nuts shall be 2 ~ 3 threads, at least 2 threads, and the exposed length of each bolt shall be basically the same. During installation, it is not allowed to compensate for manufacturing or installation errors by means of strong pulling, pushing, twisting or modifying the thickness of sealing gasket. If the pipeline installation cannot be carried out and completed continuously, the open pipe orifice shall be closed in time. The parts of the instrument sampling part on the pipeline shall be installed at the same time as the pipeline.

High pressure boiler tube is a kind of boiler tube, which belongs to the category of seamless steel tube. The manufacturing method is the same as that of seamless pipe, but there are strict requirements for the steel grade used in the manufacture of steel pipe. High pressure boiler tubes are often in high temperature and high pressure conditions. The tubes will be oxidized and corroded under the action of high temperature flue gas and steam. The steel pipe is required to have high lasting strength, high anti-oxidation and corrosion performance and good structural stability. High pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, air ducts, main steam tubes, etc. of high-pressure and ultra-high-pressure boilers.

High pressure boiler tube is a kind of boiler tube, which belongs to the category of seamless steel tube. The manufacturing method is the same as that of seamless high-pressure boiler tubes, but there are strict requirements for the steel grades used in the manufacture of steel tubes. High pressure boiler tubes are often in high temperature and high pressure conditions. High pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, air ducts, main steam tubes, etc. of high-pressure and ultra-high-pressure boilers.

Due to long-term work under high temperature and high pressure, the material of boiler tube will creep, reduce plasticity and toughness, change the original structure and produce corrosion. The steel pipe for boiler shall have: (1) sufficient lasting strength; (2) Sufficient plastic deformation capacity; (3) Minimum aging tendency and thermal brittleness; (4) High oxidation resistance, coal ash resistance, natural gas corrosion under high temperature, steam and stress corrosion resistance; (5) Good structural stability and good process properties. The steel types of high-pressure boiler tubes include carbon steel, pearlite, ferrite and austenite stainless heat-resistant steel. In order to improve the thermal efficiency of thermal power units and reduce fuel consumption, countries all over the world focus on the development of large capacity and high parameter (high temperature and high pressure) thermal power units (above 1000MW). The steam pressure increases to 31.5 ~ 34.3mpa, the superheated steam temperature reaches 595 ~ 650 ℃, and develops to ultra-high pressure critical pressure, which puts forward higher requirements for high-pressure boiler tubes. Therefore, new steel grades have been developed to meet the needs of high parameter utility boilers.