Water-powered dosing pumps with no metal parts

Paul Boughton
Dosatron is revitalising its product range and presents the Dosatron D3 product series - the latest generation of this practice-proven dosing pump to meter out and mix liquids or water-soluble concentrates. The technological is founded on a simplified design of the ‘water motor’ with no metal parts and with a driving system made of the high performance polymer Victrex Peek.

When connected to the water mains the Dosatron pump uses water pressure as its exclusive driving force. The water pressure forces the concentrate downstream and the required amount is metered and mixed with the propulsion water. The solution produced in this manner is then pumped into a water pipe. The dose of concentrate will be directly proportional to the volume of water entering the Dosatron pump, regardless of variations in flow and pressure which may occur in the main line.

The Dosatron Development Department has optimised the concept of a highly simplified differential hydraulic piston motor (17 parts instead of 52 parts). This has been possible as a result of two new Dosatron patents. The new design does not contain a single metal part and features a valve driving system with a spring blade made with the thermoplastic Victrex Peek polymer.

The exceptional mechanical properties of this polymer have enabled Dosatron engineers to proceed along a completely new course in product development. The outstanding properties of Victrex Peek, for example, excellent creep resistance, a high yield strength and fatigue performance even at high loads, have made it possible to develop a premium and reliable spring function. This entirely injection-moulded part eliminates the need for mounting of metal parts. Moreover, corrosion problems that can be associated with special steel springs are now a thing of the past as a result of Victrex Peek high level of chemical resistance even in aggressive environments. Furthermore, the polymer’s excellent resistance to fluids such as acids and chlorine products enables the dosing pump to be deployed in extremely varied application areas.  

Finally, the Dosatron dosing pump motor, designed without any metal parts around a high performance spring made of Victrex Peek, offers improved reliability and longer life, because of fewer moving parts. The motor is very easy to maintain and can be simply assembled or disassembled. The number of individual parts has been halved, chemical resistance has been improved adding greater safety, ease of use and maintenance, have all made it possible to significantly boost performance compared with the Dosatron’s previous series.

The maximum water flow increased to 3 m3/h, without increasing the frequency of cycles or pressure loss, while keeping the minimum flow at 10 l/h. The dosing rates of models currently available have been extended to 0.2-2 per cent, 0.5-5 per cent, 1-10 per cent, while models with dosing rates of 0.05 – 0.5 per cent and 5 – 25 per cent will be added in 2009. The injection settings cover injection rates of between 0.005 and 500 liters per hour with complete accuracy being maintained over the entire range. This increase in injection capacity also applies to intake suction of viscous products (powder solutions or liquids).

For more information, visit www.victrex.com

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