The main specifications of pipe fittings include diameter and pipe wall thickness (or grade).
Pipe diameter is usually nominal size (or nominal diameter, metric units of the symbol for the DN, followed by millimeters expressed) that it is for reference by convenient rounding of the value of the pipe diameter is a universal mark. In addition to the nominal size, but also useful tube diameter or diameter directly expressed in millimeters. When using a few foreign standards, one encounters the nominal size (symbol NPS, followed by the number in inches) of the product in English units. It should be noted that, between different standards or within the same standard, although the same nominal size, but the outer diameter may be different sizes. Some difference is small, such as the diameter of DN80 in GB / T12459, I series is 88.9mm, Ⅱ series is 89mm; some are quite different, such as GB / T12459 DN600 outer diameter size, Ⅰ series is 610mm, Ⅱ series of 630mm. glenflange
Pipe fittings that take over the wall thickness of the way more commonly used schedule number (SCH, followed by the value), the standard wall thickness (STD), thickened wall thickness (XS), special thick wall Thick (XXS), nominal pressure (PN), etc., but also take over the wall thickness directly expressed in millimeters.
For socket weld pipe fittings and threaded fittings are also useful pressure grade code-named 2000,3000,6000,9000 said, while the relevant standards given the relationship between the grade and the pipe wall thickness.
At present, the commonly used pipe fittings product standards, listed nominal size range between DN6-DN2000.
15.2.3 Steel pipe manufacturing process technology glenflange
(1) Manufacturing Technology Introduction
Steel pipe manufacturing is mainly involved in pressure processing technology, in addition to welding, heat treatment, cutting, nondestructive testing, surface treatment. The pressure of the pipe is the process of forming the pipe fittings, mainly based on the plastic deformation of the metal material to complete. The process can be roughly divided into hot and cold two ways, in these two ways can be divided into different pressure processing technology.