Now is not within the boiler tubes threaded into non-threaded and thread seal sealed steel tube SA-210C, now divided into three criteria: column / columns with column / cone fit and taper / taper fit. Pillar / column with: no sealing capability can be added sealing structure for low static load. Column / Cone with: sealing capability, used in low-voltage static load, such as water, gas pipes. Cone / cone with: more difficult to complete a full cone seal, often already screwed tight, but still there is a leak. But once a seal will not easily be destroyed, for high-pressure dynamic loading. 55 degrees sealing pipe thread - internal Taper internal and external threads sealed low probability, but can not easily be destroyed, can be used for high voltage withstand shock loads of occasions. GB / T 7306.2-2000 55 degrees unsealed pipe thread - the inner cylindrical threaded cylindrical outer thread does not have the seal after its internal and external thread with, only play the role of mechanical connections in the piping system, can make use of seals in the thread deputy beyond the end face of steel tubes were sealed, and more for the low-pressure pipeline system under static load. Shandong Liaocheng Polygram Pipe Manufacturing Co. provides you with Polygram Liaocheng Steel Pipe Manufacturing Co., Ltd. Our main products: electricity, petroleum, chemical, container, with the boiler industry, American standard steel pipe, seamless pipe, line pipe, oil sets pipe, spiral pipe, straight seam pipe, high alloy pipe, high pressure boiler pipe, high pressure boiler seamless steel tubes with internal thread, low pressure boiler tubes, high pressure seamless diesel, fertilizer equipment, high pressure seamless pipe, oil cracking with high pressure seamless pipe, carbon steel and carbon-manganese steel ship seamless pipe, hydraulic prop car sleeve pipe, transmission fluid line pipe, structural pipe, coal hydraulic prop tube, cold-rolled precision light tube, precision light pipe looks smooth, wall thickness uniformity, high precision. A hydraulic test: steel hydraulic test should be carried out gradually, with no penetration. Formula formula: P = 2SR / DP- test pressure (Mpa) S --- nominal pipe wall thickness (mm) D- nominal diameter steel pipe (mm) R- allowable stress two, flattening test: diameter greater than 22mm, and a wall thickness of less than 10mm of steel rebar tube flattening test conducted within the price formula is: H = (1 + a) S / a + S / DH- plane distance S --- nominal wall thickness of steel pipe D --- The nominal diameter a- unit length deformation coefficient of 0.08, when the S / D greater than or equal to 0.07 1.25, flattening test shall not have cracks and cracks. 4, bending test: pipe outside diameter less than equal to 22mm should be high pressure steel tube bending test, the bending angle of 90 degrees, the apex radius of 6 times the pipe diameter, the bend may not cracks and cracks. Liaocheng in Shandong Steel Pipe Manufacturing Co., Polygram teach you how to distinguish between true and false distinction between the ordinary high-pressure boiler seamless steel pipe and seamless pipe GB5310 between high pressure boiler seamless steel pipe GB5310 high pressure boiler tube Uses: Suitable for high pressure The minimum wall thickness of Seamless Carbon Steel Boiler and Superheater pipe. GB5310 seamless steel Dimension Tolerance: Type diameter pipe (D) wall thickness (S) diameter size (mm) tolerance (mm) diameter size (mm) tolerance (mm) hot-rolled tubes ≤101.6 + 0.4 ~ - 0.876 ~ 168.3 + 28% ~ 0> 101.6 ~ 168.3 + 0.4 -1.2 drawn tube <25.4 + 0.10≤38.1 + 20% ~ 025.4 ~ 38.1 + 0.15> 38.1 ~ <50.8 + 0.20> 38.1 + 22% ~ 0 Ordinary fluid seamless steel material containing impurities, the density of steel is small, and the size tolerance serious, so in the absence of a vernier caliper case, you can check it weighed. No ordinary seamless steel metallic luster, pale red or similar color pig iron, ordinary and small factories producing seamless seamless rolling temperature is not standard, they are visually steel temperature, so can not be prescribed normalizing temperature, the natural properties of the steel can not meet the strength requirements of the country, shoddy seamless steel prone to folding. Folding is formed on the surface of a variety of seamless fold, this defect often throughout the product vertical. The reason is due to shoddy manufacturers of folding the pursuit of high efficiency, reduction is too large, resulting in the ears, it creates a rolling when folded down, it will crack when folded products bending, the strength of steel big drop. Within the SA-210C steel tube, steel pipe manufacturers, steel pipe inside by Polygram Liaocheng Steel Pipe Manufacturing Co., Ltd. Shandong Liaocheng Polygram Pipe Manufacturing Co. (www.lcbljgg.com) (www.lcbljgg.com) (www.sdlcblj.com) (www.bljggzz.com) Shandong Liaocheng, wire, pipe, plate manufacturing equipment leaders, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Polygram steel leader with the staff warmly welcome all inquiries negotiations to create Polygram steel a better future.