Powder tankers and silo trailers have one thing in common: the discharge valve is the part that gets blamed when a load will not come out. It also has to be a drop-in fit, because the discharge assembly on a tanker is not a place for adapters and improvisation. The VT series was developed around those two facts.

A tanker discharge valve closes against a full head of material, often with conveying air pressure behind it. It must open without bridging, seal without weeping, and do so after hundreds of loading cycles in weather and road conditions. It also has to fit the standard discharge assembly the trailer was built with — because the alternative is fabricating an adapter, which no operator wants.

DIN 28459 defines a standard flange configuration for tanker discharge assemblies in Europe. Building the valve to that bolt pattern means it drops straight into the standard connection without modification. The VT series is manufactured to this interface so that a replacement is a bolt-off, bolt-on operation.

See the VT series tank truck pinch valve for the full specification.

A butterfly valve in a tanker discharge line puts a disc and a seat directly in the path of abrasive, fast-moving powder. The seat erodes and the disc becomes a target for wear. A pinch valve has neither: the medium passes through a straight elastomer sleeve and contacts nothing else. When the sleeve finally wears out it is replaced as a consumable, and the valve body continues in service.

There is a second benefit that matters to operators: a pinch valve will not bridge. Because the closure is a smooth sleeve rather than a disc swinging through the bore, there is no ledge for material to build up on between loads.

The VT series uses a cast aluminium body with a replaceable elastomer sleeve. Aluminium keeps the weight down, which matters on a vehicle, while providing ample strength for the service pressures involved. The sleeve is the wear part and the only part that contacts the product.

Tanker discharge lines are sized by the conveying rate the trailer is designed for. Selecting a valve with a smaller bore to save cost is a false economy: the higher resulting velocity erodes the sleeve faster and can restrict discharge rate enough to extend unloading time on every trip.

We supply pinch sleeves in natural rubber for abrasive dry bulk such as cement and fly ash, and in food-grade EPDM where the load is a food or feed product requiring compliance. Both are replaceable consumables; the valve body carries a 12-month warranty.

Because the failure mode of a pinch valve is gradual sleeve wear rather than a sudden jam, a fleet can plan sleeve replacement on a cycle count rather than reacting to a breakdown. Carrying one spare sleeve per vehicle is inexpensive insurance against a trailer standing idle at a delivery point.

Tell us the flange standard, the product and the discharge rate and we will confirm the size and sleeve. Browse the pinch valve range or read the bulk solids valve selection guide.