V, K or Trapezoid: Choosing a Wedge Wire Profile | ERQI WIRE

Ask three screen builders which profile they run and you usually get two answers: V for almost everything, and something else for the awkward jobs. That is not laziness. The V profile covers a wide range well. But knowing what the other two do explains why the choice is not arbitrary.

The V profile — the default for a reason

Two faces meeting at 60°, point outward. The slot is narrow at the surface and widens immediately underneath, so particles pass through instead of wedging. Flow is predictable, cleaning by back-flush works, and the profile is available in the widest spread of sizes. If nothing in the duty argues against it, this is the one to quote.

The K profile — when the slot has to stay parallel

A K-section carries a flat top with the opening cut through a wider body, so the slot is a parallel channel rather than a V. The gap is the same top to bottom, which helps when the screen is back-flushed hard and you do not want slot geometry steering the flow path. The trade is lodging: a parallel channel holds particles that a V would have released. K profiles suit screens cleaned chemically or by replacing media, not ones relying on mechanical back-flush alone.

The trapezoid — for abrasion

Flat top, sloped sides, wider at the base. A flat face takes the wear instead of a sharp edge, so the wire lasts longer in sand, gravel, slag and other abrasive duty. What you give up is open area: a flat top blocks flow that a V-point would have passed. On abrasive duty that is usually the right trade, because a worn V-screen loses its slot long before a trapezoid does.

How to decide

Start from what the screen has to survive rather than from the catalogue. Abrasive media → trapezoid. Hard back-flush with fine slots → K. Everything else → V. Then check the open area figure: if the profile you picked cannot reach it, change the profile before you change the slot, because slot size is usually fixed by the product, not by the screen.

Slot sizing is covered in how to calculate a wedge wire slot. Sections are on the wedge wire page. Tell us the duty and the slot through contact and we will say which profile we would run.