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3. Theory of the Pump
3.1 Working Principles
The pump is simple by design in its construction and operation. The medium to be pumped does
not come into contact with any moving parts and is totally contained within a robust, heavy-duty
hose, which consists of an inner layer, two - six reinforcement layers and an outer layer. A
rotating shoe passes along the length of the hose, compressing it totally closed. This motion
forces the contents of the hose directly in front of the rotating shoe to move forward along the
length of the hose in a ‘positive displacement’, peristaltic movement. In the wake of the shoe’s
compressing action, the natural elasticity of the nylon reinforced rubber forces the hose to open
and regain its round profile, creating suction pressure, which recharges the pump
3.2 Features of a Hose Pump
• Dry running - the pump will run dry without damage
• The hose effectively forms an integral part of the suction & discharge lines, connected
externally by flange or hose-tail connectors ensuring zero leakage
• Self priming - the pump will prime itself to 95% vacuum (equivalent to a suction lift of 9.5m of
water)
• High solids content handling - the pump is capable of handling media with a high proportion
of solids and with large particle sizes
• Viscous liquids - pumps are capable of dealing with fluids up to 47,000 mPas (cPs)
• High differential pressures: the pump is capable of continuously running at pressures up to 15
bar / 220 PSI
• Few moving parts - there are no valves or joints, reducing the possibility of malfunction
• Low maintenance - the main wearing part in the pump is the hose, which can be replaced
quickly, easily and inexpensively
• Non shearing - delicate media can be pumped effectively with little or no damage
3.3 Advantages of VERDERFLEX
• Compact, close coupled design, or robust long coupled option
• Rigid housing design for heat dissipation and accurate hose compression
• Quick fit flange design clamps and seals in one easy movement to speed hose replacement
• Drainage channels in the casing enable complete removal of all lubricant prior to
maintenance
• Filler tube on rear of housing to prevent damage
• Taper lock bush in rotor enables various gearbox / motor drives to be fitted
• Hose construction provides for more efficient lubrication and longer life
Conforms to and is certified to EHEDG Standards and so can be used within the intermediate
processes of the food & drinks industry, pharmaceutical industry and other hygienic related
applications
The pump has the following features in addition to the ones already mentioned which are
applicable for use within these industries:
