Pleat

A pleat is a fold in a filter medium that increases effective surface area within a compact volume. Pleated elements deliver lower clean‑medium pressure drop and longer run times when channel geometry is maintained. Critical design factors include pleat height and pitch, the pleat support or spacer that prevents collapse under ∆p, and tip/valley strength to resist fretting and abrasion. Materials range from polymeric meshes and nonwovens to metal fabrics for high‑temperature or aggressive chemistries. To avoid channeling and early fouling, spacers must provide high void volume with smooth contact surfaces; end‑caps and adhesives must seal reliably to prevent bypass. Validation covers burst and collapse resistance, flow distribution, ∆p growth under loading, and cleanability/CIP durability. Well‑engineered pleat packs combine high specific area with stable retention and predictable lifecycle cost.