What are the criteria for thin-walled stainless steel tubes?

At present, the water supply drainage product standardization committee of the Ministry of construction has organized experts to review pass two industrial standards for thin-walled stainless steel water. Pipeline stainless steel pressure fittings, the draft has been submitted to the construction unit. Pipes for liquid transportation " European standard dinen 10312-1999" stainless steel pipes fittings for liquid (including drinking water) ", British standard bs4127-1994" thin wall stainless steel pipes for main water transportation " Japanese standard jisg3448-1997" use stainless steel pipes according to general conditions ". Application scope of standard 1.2 of thin-walled stainless steel pipe: DN ＞ 150 mm, working pressure ＞ 1.6 MPa, capable of conveying drinking water, drinking water, hot water high temperature water with clean temperature of 135 ℃. 1.3 for relevant pipelines applicable places, the standard mechanical properties of thin-walled stainless steel pipes shall be free of cracks, blowholes, undercut slag inclusion on the weld surface of water pipes. The internal external surfaces shall be well treated shall exceed the wall thickness of water pipes. Tolerance of scratches, pits alignment marks. There should be no burr in the fracture. The rest shall meet the requirements of article 5.7 of B / t12771-2000 standard. The standard basic dimension of thin-walled stainless steel pipe the standard dimension deviation of thin-walled stainless steel pipe is 1.6.1 the allowable deviation of wall thickness of water pipe is ± 10% of the nominal wall thickness. 1.6.2 the length of water pipe is fixed, generally 3000-6000mm. According to the buyer's requirements, the supplier the supplier can reach an agreement, provide other fixed length. The allowable deviation is mm. 1.6.3 the curvature of water pipes shall be 3000mm to 12mm. 1.6.4 the end of water pipe shall be sawed flat, the standard end quality of thin-walled stainless steel pipe shall be 1.7 raw material manufacturing method 1.8.1 the raw material of water pipe shall be stainless steel cold (hot) rolled steel strip, the requirements shall comply with GB / t4239 Yb / t5090. The water pipe is made of stainless steel strip by automatic argon arc welding plasma welding on the pipe making equipment. Generally, heat treatment is carried out after welding. The distance between the water pipe the pressure plate is 1 / 3 of the outer diameter of the water pipe. There shall be no cracks damage after flattening. 1.9 flaring performance: when the nominal diameter of water inlet is greater than DN50 mm, 60 ° taper shall be used the expansion rate shall be 25%. After expansion, the pipe wall shall be cracked damaged. 1.10？ Standard test specification for thin walled stainless steel pipe for bending pipe with nominal diameter greater than DN25 mm. During the bending test, the bending radius is equal to 4 times of the outer diameter of the pipe. When the bending angle is 90 degrees, there should be no cracks wrinkles. 1.11.1 when hydrostatic test is conducted on water pipe, the test pressure is 2.45 MPa. Under this pressure, after ten seconds, the water pipe shall be free leakage deformation. 1.11.21 during the air pressure test, the water pipe shall be air tight air pressure tested. The pressure of liquid medium is 0.6 MPa, the test pressure of gas medium is thin-walled stainless steel tube. The standard test specification is 1.7 MPa. After immersing the water pipe in water for 10 seconds, there should be no bubbles in the water pipe. 11.11.31 when eddy current flaw detection is carried out on water pipes, the artificial standard defects (drilling diameter) shall meet the class a requirements of GB / t7735. 1.121 sanitary requirements 1 when the user requires carries out type inspection, the pipes used for drinking pure water, domestic drinking water drinking water shall meet the requirements of B / t17-219 after immersion.