BENDING

Bent sections that we manufacture may be divided into bent elbows, segment elbows, flat offset pipes, and '3-dim.' offset pipes. For such bent elbows the maximum length of their arms is ~6m; the longer arm shall not be less than ~0.5m. The maximum bending angle varies between 5° and 180°. We are in position to bent with radii of 1.5D; 2D; 2.5D dependent on the actual diameter and wall thickness. The bending angles for specific diameters are presented in table.

For the Y-branches their bending angles range between 5° and 90°, and the length of the shorter arm as projected does not exceed 1.1m. The ovalisation of pipes within the bending area is 1% to 4%. The reduction of the original wall thickness on the external bending radius is:

• max. 25% for R = 1.5D;

• max. 21% for R = 2D;

• max. 18% for R = 2.4 D and 2.5D.

The accuracy of the bending angle +/- 0.5°. The bending process is conducted on the bending machines 1003CNC and 1008CNC.

The alternative to the bending process is the application of Hamburg elbows or segment elbows. We apply Hamburg elbows in diameters ND20 to ND600 and with wall thicknesses as requested by Customers. The standard bending angle of Hamburg elbows is 1.5D. Arches are fastened to the pipe by butt-welding.

Segment elbows are manufactured to the standard ZN-5003 within a diameter range ND 125 to ND 500 with wall thicknesses up to 20mm. There are two basic angles i.e. 15° and 11.5° applied while cutting segments. By using an appropriate number of such segments we attain the maximum angle of 180°.