Now is not within the boiler tubes threaded into a non-thread sealing and thread sealing, now divided into three criteria: column / pillar with the 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, in the piping system only play the role of a mechanical connection capillary steel prices, can make use of seals Vice beyond the end face of the thread sealed capillary tube, used for 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 pipe flattening test capillary pipe manufacturers, the formula is: H = (1 + a) S / a + S / DH- flat steel distance S --- D --- nominal wall thickness of steel 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: 22mm outside diameter less than equal to the pipe shall be tested by bending the bending angle of 90 degrees, the apex radius of 6 times the pipe diameter, the bend may not cracks and cracks, cracks. Capillary Steel Plant, capillary pipe specifications (certified), capillary pipe provided by the Shandong Liaocheng Steel Pipe Manufacturing Co., Polygram. 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. You can also access (www.lcbljgg.com/supply_details_39570165.html), for more information about the company.