Two diverter valves that look similar from a distance can be specified in completely different materials. In our range the split is deliberate: the KFB plate, KFZ plug and KFQ ball diverters are supplied in stainless steel, while the VAB flap diverter is built in aluminium. Understanding why makes the selection straightforward.

The body material of a diverter has three jobs: carry the structural load of the connection and any internal pressure, resist the corrosive effect of the product and the environment, and last as long as the installation. What it does not do is determine how the valve seals — that is the job of the sealing element, and it is a separate decision.

The KFB, KFZ and KFQ designs are used where the seal genuinely matters — where the inactive port must be closed against product, and often against differential pressure from a pneumatic conveying line.

The VAB flap diverter valve exists for a different set of priorities. Its purpose is to redirect light dry powder and air-conveyed product, in installations where weight is a real constraint.

Read the flap diverter valve application guide for where this design is used in practice.

Within stainless, the choice is usually between 304 and 316. 316 adds molybdenum, which substantially improves resistance to chlorides and to aggressive chemicals, and is the standard for marine, chemical and pharmaceutical duty and for any environment where pitting or crevice corrosion is a risk. 304 is the general-purpose grade and is the right answer for most food and general industrial applications. Specify 316 where the extra resistance is genuinely needed rather than by default.

It is worth repeating, because the two are often confused. Body material decides structure and corrosion behaviour. It does not decide how tightly the diverter seals or how it resists abrasion at the sealing interface — those are matters of design and of the sealing element.

The same logic applies in a pinch valve, where the medium never touches the body because the sleeve lines the flow path. There, material choice is purely structural and external, and the sleeve compound is the decision that governs life.

Tell us the product, the environment and the duty and we will recommend a construction. Browse the diverter valve range, read the pneumatic conveying valve guide, or view the full product range.