Engineering calculators / Geometry & flow
Filter Cylinder Developed Blank Calculator
Estimate the developed circumference and rectangular blank size for a straight cylindrical wall. Prefer a verified development reference diameter; keep seam overlap separate from trimming allowances.
Example inputs demonstrate arithmetic only. Unit changes convert existing values.
Formula and assumptions
Dref = Dout − t or Din + t (mid-wall model); B = π × Dref + overlap + 2 × edge trim; Hblank = Hfinished + 2 × end trim
The verified reference mode uses your supplied diameter directly. Outside/inside modes assume a circular wall with the development reference at half the thickness; they do not determine a material-specific neutral axis or K-factor. Springback, forming strain, mesh deformation, weld shrinkage, seam fit and end connections require drawing or sample validation. No automatic welding allowance is added. For a butt seam, set overlap to zero and enter only confirmed trimming allowances. Not for cones, pleated media, spiral seams, oval tubes or multi-layer walls with different development lengths.
Frequently asked questions
Can I calculate from outside diameter alone?
Use a verified development reference, or supply thickness and accept the explicit mid-wall approximation. Outside circumference alone is not an exact developed blank length.
Is the result a final cutting drawing?
No. Confirm material, forming route, reference diameter and allowances by drawing or sample before production.
Are the end allowances per end or total?
Each axial end allowance is added twice. Seam overlap is entered once as total extra circumferential width.
Does blank area mean effective filtration area?
No. The geometric blank area includes overlap and trims and does not account for openings, support blockage or installed exposure.
Unit definitions: NIST SI conversion factors. Geometry is calculated from the explicit model above.
