Shell with Nozzle Holes: flat pattern
A cylindrical shell unrolled to a rectangle, with the holes for up to four radial nozzles marked in their developed shape. A cylindrical shell course unrolled to a rectangle, with the holes for up to four radial nozzles marked in their developed shape.
Open the shell with nozzle holes in SheetMorphConfigurations
- One nozzle. A shell with one nozzle hole.
- Two nozzles. A shell with two nozzle holes.
- Three nozzles. A shell with three nozzle holes.
- Four nozzles. A shell with four nozzle holes.
A worked example
The one nozzle configuration with the sizes SheetMorph opens with, in mm. One plate, the unrolled shell, with 1 nozzle hole marked: 1 part, 1 seam.
| Blank, the rectangle the plate is cut from | 3139.7 mm × 1500.0 mm |
| Length of cut, every outline and hole | 9279.4 mm |
| Shell diameter | 1001.00 mm |
| Length | 1500.00 mm |
| Girth of the plate | 3144.73 mm |
| Hole diameter | 300.00 mm |
| End A to its axis | 500.00 mm |
| Angle round the shell | 0.00 ° |
| From the middle of the plate, round the shell | 0.00 mm |
| Width of the hole on the plate | 304.68 mm |
| Wider than its diameter by | 4.68 mm |
| S1 Shell, long | 3139.69 mm |
| S1 Shell, wide | 1500.00 mm |
| Plates | 1 |
| Triangular facets | 64 |
| Pattern extent X | 3139.69 mm |
| Pattern extent Y | 1500.00 mm |
| Area of the blanks | 4,709,528 mm² |
| Area cut out | 71,189 mm² |
| Net area | 4,638,339 mm² |
| Total cut length | 10225.92 mm |
| Longitudinal seam length | 1500.00 mm |
How it is developed
Parallel-line development (unrolled cylinder). This is a triangulated approximation: the curved surface is divided into small flat triangles, each laid out at its true size. The finer the division, the closer the pattern is to the surface; SheetMorph states the deviation it found.
- The shell unrolls to a rectangle as long as its girth and as high as its length, cut along the seam on the -X side.
- A round nozzle meets the shell in a curve that, laid flat with the plate, is as long along the shell as the hole diameter and wider round it: the larger the nozzle against the shell, the wider. Each hole is drawn in that shape, to be cut before rolling.
- The weight is for the plate with the holes cut out.
Checked before it can be exported
Every pattern SheetMorph draws is checked against the 3D part it comes from. For this example:
- Surface connectivity (passed): 64 facets form one closed band: every edge inside a part joins exactly two facets, every open edge one (V - E + F = 0).
- Developed edges equal true 3D lengths (passed): 192 facet edges compared between the 3D surface and the flat pattern (max deviation 5.81e-12).
- Shared edges and seam closure (passed): 63 internal edges are shared vertex-for-vertex between adjacent facets; 1 seam(s) have mating edges of equal true length (max deviation 0).
- Developed facets consistently oriented (passed): All developed facets are counter-clockwise (outside face up); none is mirrored or degenerate.
- Developed area equals surface area (passed): Facet area in 3D and in the flat pattern agree (difference 1.07e-7).
- Cut outlines closed and non-overlapping (passed): 1 closed outline(s); no outline crosses itself or another outline.
- HOLE-N1 lies within its plate (passed): 48 points of the hole compared with the edges of the plate; its developed area is 71188.9967.
Assumptions
- The pattern is developed on the mid-thickness surface; inside or outside sizes are converted to it by the thickness.
- Curves are chains of chords between division points.
- No seam, lap, weld-preparation or pressing allowance is added.
Limits of this module
- Nozzles are radial only; offset (hillside) and inclined nozzles are not modelled.
- The nozzles themselves are not developed here: use the tee module for a branch with its saddle.
- A hole may not cross the seam, an end of the shell or another hole.
- Curves are chains of straight chords between division points.
- No seam, lap, weld-preparation or pressing allowance is added, and plates are not nested onto stock sheets.
Conventions
Coordinate system. The part stands on the Z axis with End A at Z = 0. Angles round the axis are measured from +X toward +Y, counter-clockwise seen from +Z.
Divisions and thickness. A circle is divided into 4N equal chords. Sizes are inside, mid-thickness or outside sizes; the pattern is developed on the mid-thickness surface and the views show the sizes as entered.
Shell and seam. The shell stands on the Z axis from End A to End B. Its seam is on the -X side, at 180 degrees, so that a nozzle at 0 degrees is in the middle of the plate.
Nozzles. A nozzle is radial: its axis crosses the shell axis at right angles. Its position is measured from End A to its axis, and its angle round the shell from +X, positive toward +Y, between -180 and 180 degrees. The diameter is that of the hole to be cut. On the plate the hole is as long along the shell as its diameter, and wider round the shell.
Change the sizes to your own in SheetMorph, check the drawing, add seam and flange allowances, and export DXF, PDF, SVG, CSV or G-code. Check every pattern against your own standards before cutting.
Open the shell with nozzle holesOther vessels
- Tank Shell: The shell of a storage tank or silo in courses and plates from stock, the vertical seams staggered, with a nozzle or manway marked on its plate.
- Silo: A silo, bin or hopper as one job: the body, the cone bottom from its wall angle, the spout, a support skirt and a cone roof, with what it holds.
- Reinforcing Pad: The pad welded round a nozzle on a shell or a pipe: rolled to the shell, with the hole for the nozzle and a tell-tale hole, whole or in two halves.
- Sphere: A sphere made of plates: gores from pole to pole, or zones round it, with a round cap at each pole.
- Dished Head: A vessel head in petals round a crown plate: torispherical, hemispherical, semi-elliptical (2:1), or a cone with a knuckle.