Essex based pump supplier, Triark Pumps, was approached by leading chocolatier, Hotel Chocolat, with the challenging task of adding a solids handling functionality to the pumping of its brand famous chocolate.

The pumps in question needed to handle an already troublesome medium, namely chocolate, but in this case, with the addition of ‘inclusions’, such as nuts and raisins.

Having serviced all of the main chocolate producers in its 30+ years of business, Triark knew only too well that chocolate is one of the most difficult fluids to transfer correctly and requires an expert approach.

Chocolate solidifies when cool – we eat it at ambient temperature – so it has to be kept warm, not only as it moves along the pipelines, but also through the pump. The main issue is that chocolate is ‘shear sensitive’, meaning the cocoa butter and cocoa solids can easily separate if moved too fast, which can in turn burn the chocolate.  This is not something that a high-end confectionary producer can allow. Chocolate will also react the same way if the discharge pressure is anywhere over 100psi, so correct configuration of the discharge lines needs to be born in mind too.

Triark Pumps’ engineers initially considered using an Air Operated Double Diaphragm (AODD) pump, its most successful pump type for chocolate based applications to date, but the lack of a localised compressed air supply meant that a different approach was required.

Unfortunately, the overall choices were limited given the need for an electrically operated pump that could run slow (due to the shear sensitive nature of chocolate), handle solids (nuts and raisins) and be heated, so that the chocolate wouldn’t cool during both the normal running cycle or when the system stopped for any reason.

Having carried out extensive ‘pre-selection’ research before discussing possible options with a number of its key suppliers, they identified several alternatives from the likes Alfa Laval, Grundfos and Desmi.

Eventually though, and drawing upon the experience gained during a previous visit to India by Triark’s Managing Director, David Rozée, where he witnessed Desmi pumps in operation at a leading manufacturer of semi-finished cocoa mass, the most appropriate solution was determined.

Triark supplied two Desmi Rotan 2” positive displacement internal gear pumps, comprising cast iron casing and rotor, mild steel shafts, bronze internal bearings, front and rear heating jackets, packed gland seal and secondary lip seal.  Each pump was flexibly coupled to an SEW 1.5 kW, IP55, EFF1 gear motor and mounted on a fabricated ‘top hat’ style stainless steel base plate, with a stainless steel coupling guard.

Commenting on this application, David Rozée, Managing Director, Triark Pumps, said, “Desmi has built an enviable reputation in the manufacture of pumps for the food and drink sector, so not only did the eventual selection provide a quality solution which to date has been running without issue, it also provided the most cost effective option, enabling us to tick every box on the original brief”.

So, when you next enjoy a piece of Hotel Chocolat confectionery, you can do so in the knowledge that the product may not be quite as smooth and rich without the support and expertise of Triark Pumps.

For further information on this or any other Triark Pump application, please contact David Rozée on +44 1621 781144.

For a technical demonstration of the Desmi Rotan pump, please view the video at