Industrial Plate Screens Perforations – Holes Shape, Aperture Size, Pitch, Arrangement

Designating various kinds of perforations and their arrangements in industrial perforated plate screens.

The perforation of a plate is designated by

— shape of the holes;

— aperture size w, or aperture sizes w₁ and w₂ in case of slots;

— mutual arrangements of holes;

— pitch p, or pitches p₁ and p₂ in cases where the pitches are different in directions parallel to the edges of the plate;

— orientation of the arrangement of the perforations relative to the edges of the plate.

Shape of holes – Perforations in Industrial Plate Screens

The shape of holes shall be designated by the following symbols:

• R: circular (round).
• C: square, with sides parallel to the edges of the plate.
• CD: square, with diagonals parallel to the edges of the plate.
• H: hexagonal.
• LR: slots with round ends.
• LC: slots with square ends.

Aperture size – Perforations in Industrial Plate Screens

Following the symbol for shape of hole, the aperture size shall be stated in millimetres.

• Aperture size of square or circular: W, Aperture size of slot: w₁ × w₂.
• W is the width of square or diameter of circular.
• w₁ is the width of a slot, and w₂ is the length of a slot.

Figure 1 — Code for shape of holes.

Figure 2 — Examples of coded shape of hole and aperture size

Arrangement of holes

Arrangement of holes includes U, Z, M, T, arrangements.

Pitch – Perforations in Industrial Plate Screens

For shapes R, C, CD or H in U- or Z-arrangements, both pitches shall be stated: p₁ × p₂.

• p₁ is the shorter one pitche, and P₂ is the longer.
• In the case of a U-arrangement, when p₁ = p₂, only p shall be stated.
• For M- or T-arrangements, only p shall be stated

Figure 3 — U-arrangement

Figure 4 — Z-arrangement

Figure 5 — M-arrangement

Figure 6 — T-arrangement

Figure 7 — Example R10 U15 × 20

Figure 8 — Example C5 Z10 × 20

Figure 9 — Example LR3 × 10 U12 × 18

Figure 10 — Example LC3 × 10 Z18 × 12

Figure 11 — Example C10 U20

Figure 12 — Example LC10 × 15 U20

Figure 13 — Example CD8 M12.5

Figure 14 — Example H10 T16

Orientation of the perforation on the plate

The orientation of the perforations with the edges of the plate affects the performance as an industrial screen.

• T-arrangement
  • Orientation 1 shall be with pitch p parallel to the longer edge (see Figure 15);
  • Orientation 2 with p parallel to the shorter edge (see Figure 16).
• Shapes R, C, CD and H in U- and Z-arrangements
  • Orientation 1 shall be with the shorter pitch p₁ parallel to the longer edge (see Figure 17);
  • Orientation 2 shall be with the shorter pitch parallel to the shorter edge (see Figure 18).
• Shapes LR and LC (slots) in U- or Z-arrangements
  • Orientation 1 shall be with the width w₁ parallel to the longer edge (see Figure 19);
  • Orientation 2 shall be with the width w₁ parallel to the shorter edge (see Figure 20).

Figure 15 — T-arrangement, Orientation 1

Figure 16 — T-arrangement, Orientation 2

Figure 17 — Example C5 Z10 × 18 Orientation 1

Figure 18 — Example C5 Z10 × 18 Orientation 2

Figure 19 — Example LR3 × 18 Z12 × 36 Orientation 1

Figure 20 — Example LR3 × 18 Z12 × 36 Orientation 2