Double Cut Cylinder development

What it is

A rolled shell cut at an angle on both ends, each with its own angle. Developed, it gives two waves — one per edge — which can differ in height and phase. It is the part that clears two offsets with a single length of tube.

Where it is used

Connecting runs between misaligned equipment, intermediate gores of field-assembled bends, adaptations to existing pipework.

Measurements the calculation needs

• D Outside diameter of the tube
• X Straight run between the two cuts
• ANG1 Cut angle of the first mouth
• ANG2 Cut angle of the second mouth
• DV Divisions
• THK Plate thickness

Worked example

The values the form comes pre-filled with, run through the tool itself:

Outside diameter of the tube	200 mm
Straight run between the two cuts	100 mm
Cut angle of the first mouth	35°
Cut angle of the second mouth	35°
Divisions	16
Plate thickness	10 mm
The flat pattern fits a plate of	597 × 187 mm
Flat patterns produced	2

Result of the example

Plate 1	597 × 187 mm
Plate 2	597 × 187 mm

Assembly notes

Weld the sheets with the longitudinal seams 180° apart, not lined up. Lined up, the piece assembles into a different shape — and the longitudinal seam crosses the circumferential one.

Frequently asked questions

Do both angles have to match?

No. Each opening takes its own angle, which is the point of the part: solving two different offsets in one cut of plate.

Why does the result come in two flat patterns?

The part is delivered as two halves that together close the tube. Each half can be checked separately against the single-cut cylinder.