Knowledge of fittings

One, the pipeline system overview

For conveying liquid or gas, must use all kinds of pipe, the pipe, except straight pipe with steel pipe is used all kinds of pipe fittings, pipe bend must use elbow, pipe size head, should be used when variable diameter tee, should be used when bifurcation pipe joint and the joint should be used when connecting flange, to achieve the purpose of open medium, but also in all kinds of valves, to reduce the thermal expansion from the cold or frequent vibration on the influence of the pipeline system, but also with expansion joint. In addition, in the way of tube, and connected to all kinds of instruments and meters of various connectors, plug, etc. We are used in the pipe system will be other than straight pipe fittings are collectively referred to as tube fittings.

Second, the pipeline system of common sense

Pipe commonly used materials:

Raw materials are: pipe is commonly used in sheet, pipe and forgings.

Sheet (1) : common plate are rolled plate, plate and opened plate. Plate bending rolls delivery, usually advantage is that can use either intercept length, the disadvantage is that there must be a corresponding decoiling equipment, surface roughness. The tablet is usually a piece of delivery, advantage is board face level off, the convenience of transportation, utilization rate is low. Defect is sometimes panel used opened plate is rolled plate through the shearing machine cut into pieces after board face level off. The distinction between tablet and opened plate method, in addition to observe the surface and edge roughness, smoothness, and a simple method: real tablet, each have a steel factory in markup, such as manufacturers, specifications, steel grade, and no these marks on the open flat.

2 pipes: this is mainly refers to the circular tube, can be divided into welded pipe (straight seam welded pipe, spiral welded pipe) and seamless tube. Welded pipe (is also called tube) is typically used for low pressure pipe (20 kg/CM2), the spiral welded pipe and is mainly used for large diameter (such as DN400 above) system, therefore, its general thin wall thickness (usually under SCH10) seamless tube is generally used in the pipeline of high pressure, due to the limitation of seamless steel tube production process, we often use the seamless steel tube industry, is usually hot, and so on the market for hot-rolled seamless pipe wall thickness, to a certain diameter of pipe, is usually have certain lower limit (generally in the SCH10 above), the such as:

27 - Φ Φ 48 wall thickness of 2.0 or higher

57-76 Φ Φ wall thickness of 3.0 or higher

Φ 89 - Φ 159 wall thickness of 3.5 or higher

Φ 168 - Φ 219 wall thickness of 4.0 or higher (Φ 168 * 3 market, but less)

Φ 273 wall thickness of 6.0 or higher

Φ 325 - Φ 377 wall thickness of 8.0 or higher

Φ 402 - Φ 426 wall thickness of 9.0 or higher

Φ 530 - Φ 630 wall thickness of 10.0 or higher

Tubing weight per meter theory calculation formula is:

Carbon steel management heavy = (foreign economic - wall thickness) * 0.02466 * wall thickness (mm, for the unit weight of kg)

Stainless steel management weight = (foreign economic - wall thickness) * 0.02491 * wall thickness (mm, for the unit weight of kg))

For example, a 6 meters long, 273 * 8 stainless steel pipe:

Richard weight per meter = (273-8) * 8 * 0.02491 = 52.81 Kg

6 m a heavy = 52.81 * 6 = 316.86 Kg

(3) forgings: flange, forgings are usually used in the manufacture of bearing plug-ins and some connectors.