Dura 5 and Dura 7

Verderflex is pleased to introduce its new Dura 5 and Dura 7 high-pressure low-volume dosing pumps. So, why use the Dura 5 and 7?

High-pressure low-volume dosing

The Dura 5 and 7 deliver stable sub-litre per hour flows at either 5 or 8 bar in a rugged hose pump format.

Care-free pumping of off-gassing liquids

Municipalities regularly use sodium hypochlorite (hypo) to disinfect drinking water and the food industry uses hypo to prevent bacterial contamination. When pumped, hypo off-gases vapour locking a diaphragm pump’s chamber, resulting in additional degassing valves. Often pumps are set to "over-dose" to compensate for the loss of performance leading to increased chemical usage. Hose pumps are a well proven solution and also address the associated crystallisation issues.

Eliminate abrasive wear costs

Lime or kalkmilch is a very common pH adjustment chemical, used in water treatment, industrial waste remediation and process acidity control. Lime’s fine particles are highly abrasive and cause severe stator and valve wear resulting in high pump ownership costs. Verderflex has many years experience solving this pumping problem and peristaltic pumps are accepted as the proven valve free solution to pump lime. The Dura 5 and 7 now bring this proven performance to lower flow rates.

Reduce chemical usage

Peristaltic pumps have a gentle, low shear pumping action that maintains particle size and reduces the flocculation chemical volumes. In contrast, traditional solutions often shear flocculent particles increasing chemical use and result in higher operating costs. The Dura 5 and 7 bring these benefits to lower chemical low flow rates.

Kill clogging costs

Viscosity variations cause metering pumps to clog up requiring maintenance intervention. The Dura 5 and 7 use re-enforced hoses to generate powerful suction eliminating both the performance variability caused by minor viscosity fluctuations and the consequential clogging maintenance costs. Additionally, the truly reversible Dura 5 and 7 allow pumps to run backwards and clear blockages unlike non-symmetrical tube pumps where flow rates change with pumping direction.


Many reagents crystallise when the metered chemical flows are interrupted resulting in a loss of performance, whereas the abrasion resistant Dura 5 and 7 pumps maintain flow rates.

No tube re-tensioning

Some peristaltic pumps use continuous lengths of non re-enforced tubes which require re-tensioning after initial installation. The long life heavy-duty Dura 5 and 7 hoses are fit-and-forget.

True dry priming

Dura 5 and 7 dry prime to 9.5m of water compared to sub 5m wet-primed lifts associated with diaphragm pumps. The Dura 5 and 7 now eliminate the need for pre-wetting and priming in lower volume chemical feed systems.

Halt dry running problems

Progressing cavity pumps cannot tolerate any interruption in their liquid feed lines or the result is costly burnt stators and downtime. The Dura 5 and 7’s hoses are lubricated from the outside and bring care-free, operator proof pumping to lower flow rates.

No ancillary equipment

Conventional metering solutions need back pressure, foot and degassing valves. The Dura 5 and 7 fixed occlusion rotors simplify installations and eliminate additional parts by maintaining a separation between supply and discharge lines.

Stable liquid delivery

Many metering pumps lose accuracy when flow rates or system pressures change. However, the powerful restitution of the Dura 5 and 7 hoses give consistent dosing accuracy even under varying operating conditions.

Superior secondary containment

The pumped liquid is totally contained inside the Dura 5 & 7’s high pressure hose and each hose is totally contained inside the pump casing. This results in superior secondary containment, allows pre-spillage detection and may eliminate special spillage bunds.

High margin of safety and secure clamping

The heart of the Dura 5 and 7 is the re-enforced hose with a burst pressure in excess of 80 bar (1150psi), unlike non-re-enforced tubes that can easily burst and rely on crimped connections.

Superior viscous performance

Diaphragm dosing pumps require customers to use more complex special liquid ends for 200 CPS liquids and non-re-enforced tubing’s recovery limits tube pumps operating speeds. The powerful restitution of the Dura 5 and 7’s re-enforced hoses gives problem-free pumping of 1,000 CPS plus liquids and eliminates flow fluctuations without requiring additional parts.

Maintenance simplicity

Only the easy-to-change hose is in contact with the pumped liquid. Downtime is minimised dramatically with infrequent servicing and hose lives in the thousands of hours. Simple on site changeovers can be made by semi-skilled staff, lowering the total metering solution ownership cost.

Simple user controls

Hose pumps need no complex local keypads. Dura 5 and 7 pumps can be remotely controlled by inverters eliminating operator confusion and maintaining control system simplicity. These inverters can be the familiar site standard brand, further simplifying the control system support requirements.

Scalable performance

The Dura 5 and 7 have the same common casing and mounting frames as the Dura 10. Should system demands change, flow rates are easily scaled up or down on site by replacing the hose and a few standard components.