Verderflex Dura 35 Peristaltic Hose Pump

Overview

The Verderflex Dura 35 is a compact, high-pressure, medium-flow peristaltic hose pump from Verder Liquids, built for dosing, metering, sampling, high-lift and medium-head transfer duties in chemical processing, industrial plants, water treatment and effluent and wastewater processing. Built around a 35 mm bore reinforced hose, the pump reaches a maximum flow rate of 5,488 l/h and a maximum discharge pressure of 16 bar, with a suction lift of up to 9.5 metres water column. Because the fluid only touches the inside of the hose, there are no seals or valves in the product path, which is why the Dura range handles abrasive slurries, high-solids sludge, viscous media and gassy liquids that quickly wear out conventional rotodynamic or valved pumps.

Seven Star LLC supplies the Verderflex Dura 35 to process plants, utilities and EPC contractors across the Sultanate of Oman and the wider GCC, with engineering support in Muscat. Our team helps buyers in Muscat, Sohar, Duqm and Salalah confirm hose compound, speed and drive selection against the manufacturer datasheet before an order is placed, so the pump that arrives on site matches the real duty rather than a catalogue headline figure.

Operating Principle

The Verderflex Dura 35 works on the peristaltic principle. A cast-iron rotor turns inside the pump housing and progressively squeezes the reinforced hose against the housing wall. The compressed section of hose seals the line completely, and as the rotor advances, the occlusion pushes the trapped volume towards the discharge port while the hose behind it recovers its round shape and creates a vacuum that draws fresh fluid in. Each rotor revolution moves a fixed volume of approximately 0.65 litres, so delivered flow is directly proportional to pump speed and the pump can be used for repeatable metering as well as bulk transfer.

The practical consequences of that principle are significant on a working plant. The Verderflex Dura 35 is self-priming and copes with gaseous liquids without vapour-locking, it can run dry without damage, and its gentle, low-shear action does not break down flocculated sludge, polymer solutions or shear-sensitive products. Since there is no mechanical seal and no check valve, there is nothing for grit to wedge open and nothing to leak at the shaft. The datasheet rates the Verderflex Dura 35 for incompressible solids up to 3.5 mm and compressible solids up to 8.75 mm, which covers most lime slurries, sludge lines and mineral suspensions found in regional treatment works.

Engineering Design of the Verderflex Dura 35

The Dura generation introduced a close-coupled layout in which the pumphead is mounted directly on the gearbox flange, giving Verder the smallest footprint in its class, with up to 70% less floor space than comparable long-coupled hose pumps. The rotor sits centrally over the bearing, which reduces radial forces, gives smoother running and lowers power consumption, while an air gap between the pumphead and motor keeps lubricant heat away from the drive. The pump housing and rotor are cast iron (GG25) in green powder coat, the front cover is carbon steel with a Plexiglass inspection window so operators can see the hose and lubricant condition, and the drive shaft is EN24T steel running in bearing steel bearings with an FKM shaft seal (PTFE optional).

The 316 stainless steel port flange uses a universal slotted design that fits DIN PN16 DN32, ANSI 150# 1 1/4 inch and JIS10K 32 pipework, so the same pump drops into European, American or Japanese standard piping without adaptors. Options include 304 stainless steel flanges with a polypropylene or PVDF insert for corrosive chemicals, DIN11851 hygienic and DIN32676 Tri-clamp connections. The hose runs in Verderlube, a glycerine-based lubricant, or Verdersil, a silicone-based lubricant for duties above 50°C. The complete Verderflex Dura 35 without drive weighs about 70 kg, and standard 50 Hz configurations use a worm gearbox suitable for inverter duty.

Key Features

The Verderflex Dura 35 combines high pressure capability with a small footprint and simple maintenance. Its main features, taken from the Verder datasheet, are:

• Maximum flow of 5,488 l/h and discharge pressure up to 16 bar, suitable for long transfer lines and filter press feed.
• Suction lift up to 9.5 mwc with genuine self-priming, so the pump can draw from sumps, tanks and drums without a flooded suction.
• No seals or valves in contact with the fluid, which removes the most common leak and wear points of conventional pumps.
• Dry-running capability and gentle low-shear pumping action that protect both the pump and sensitive products.
• Handles abrasive, high-solids and viscous liquids, with solids up to 3.5 mm incompressible and 8.75 mm compressible.
• Close-coupled design that saves floor space and simplifies skid layouts in crowded plant rooms.
• Choice of hose compounds: natural rubber, NBR, EPDM, food-grade NBRF, Hypalon (CSM) and Verderprene for chemical compatibility.
• FDA CFR21 and EC/1935 conformity, with ATEX available as an option for hazardous areas.

Industrial Applications

In water and wastewater, the Verderflex Dura 35 is a natural choice for lime slurry dosing, ferric and alum dosing, polymer transfer, sludge transfer and thickener underflow, where abrasive particles quickly destroy the mechanical seals of centrifugal pumps. In chemical plants the Verderflex Dura 35 transfers acids, alkalis and solvents with the right hose and flange insert, while its accurate volume per revolution supports metering into neutralisation tanks. Mining and mineral processing sites use the Verderflex Dura 35 for tailings samples, flotation reagents and filter press feed, and it is also common in breweries and food plants for yeast, spent grain and process residues.

Across Oman and the GCC, Seven Star LLC supplies the Verderflex Dura 35 for RO desalination pre-treatment chemical skids, municipal sewage treatment plants, district cooling water treatment, and industrial facilities in the Sohar and Salalah free zones and the Duqm special economic zone. For engineers who are comparing pump technologies, the Verderflex Dura 35 sits alongside lighter-duty hose pumps such as the Verderflex Rapide peristaltic hose pump, air-operated designs such as the Verder VA25 air-operated double diaphragm pump, and progressing cavity units such as the NETZSCH NEMO BY NM038BY, and our Muscat team can explain where each one is the better fit.

Technical Specifications

The table below summarises the Verderflex Dura 35 datasheet values (metric, 50 Hz). Flows are typical and were measured by the manufacturer with water at 20°C.

How to Order

To request a formal quotation for the Verderflex Dura 35, send Seven Star LLC your fluid, solids content, temperature, required flow and discharge pressure, and our engineers will confirm the hose compound, speed and drive. The Verder datasheet is available for download on this page, and our pump team in Muscat provides availability checks, delivery to sites across Oman and the GCC, and support with spare hoses and lubricant.