ITT Flygt pumps up the durability

The new force in de-watering pumps is expected to exceed current market standards in terms of durability. ITT Flygt's new hydraulic design, the 2600 Series, is launched this month and the company says it will provide longer periods of maintenance-free operation, even in the most demanding conditions.

In 1947, Flygt engineer Sixten Englesson developed a prototype for the world’s first submersible drainage pump, which came to be known as the parrot cage.

The pump, also called the Bibo-pump, brought about a revolution in the mining and construction industries because operators could totally submerse in water a pump with a close-coupled electric motor. More than 70,000 have been sold in the UK to date.

The 2600 Series is Flygt’s most important product launch to date since the Bibo pump was first introduced because for customers it provides a new standard in de-watering pump technology.

For the past four decades, the Bibo 2000 Series of drainage pumps have been solid performers in the construction industry, de-watering sites, irrigation, power station lagoons and most dirty water situations requiring a transportable pump capable of withstanding abrasive content, such as sand.

With motor sizes of 0.75-90kW and output flows up to 280l/s, they have been one of Flygt’s most successful and long-lasting heavy-duty submersible pump ranges.

The use of Bibo pumps on prestigious schemes such as the Channel Tunnel project, one of the largest UK supply-only contracts, is testament to their capabilities.

Flygt Bibo drainage pumps were used on the Channel Tunnel project for their

reliability, superior wear parts resistance, and importantly the backing of Flygt’s support and technical services.

More than 500 Flygt Bibo pumps were supplied to the UK side, each one aiming to keep operations moving throughout the life of this ground-breaking project.

According to Simon Jones, Flygt project engineer: “Many original Bibo pumps are still going strong, providing a clear reflection of Flygt’s dedication to product quality and commitment to service.

“Now as a leading supplier of de-watering products, the reason for the step change is that the basic models within the Bibo 2000 range are between 25 and 40 years old.

“While they continue to fulfil customer and end-user requirements, and three models – the 2201, 2250 and 2400 – will still be available, we wanted to develop a new generation of de-watering pumps which meet the needs of today’s changing marketplace.”

Jones continues: “The new range delivers improved value for money through a less complicated assembly and reduced number of parts, making it easier and more cost-effective to service and maintain over time. This significant R&D takes into account customer feedback and our own research through field trials and factory testing.”

Reducing wear

The ambition of the 2600 Series is to reduce the need for maintenance and to increase the pumps’ durability and reliability, giving a better pump for the same price. Following several years of work and innumerable tests, both in the lab and on the field, a solution has taken shape. Six models replace 11 models within the existing Bibo range.

Jones, says: “The new pumps’ aim is to provide customers with the lowest overall cost of ownership, by radically reducing both component wear and maintenance to maximise working time and profitability.

“The need to keep operations moving is a key driver for all users. These pumps play a crucial role to remove water from the workplace, thus allowing work to continue, but should require little or no attention.

“The 2600 pumps have been designed to do just that – with innovative Dura-Spin hydraulics, fewer components and an overall design that makes the whole range simple and quick to maintain.”

The six pumps in the range cater for many tough de-watering applications of every size by using motor sizes of 1-18kW, discharge sizes from 51-152mm and output flows of 36-324Ml/h.

The main differences with the new design of 2,600 de-watering pumps compared with the Bibo lie in their hydraulics, features to improve reliability even further, appearance, servicing and materials.

An open impeller has been replaced by Flygt’s new patented design – Dura-Spin – to substantially reduce the risk of solid particles reaching the gap between the impeller and the pump housing, thereby avoiding wear.

This is achieved with a closed pump impeller and a specially designed vane that has swept-back leading edges and a spiral relief groove on the opposite surface of the pump housing.

The design of the impeller prevents abrasive particles reaching the impeller neck, considerably increasing durability during normal operation and dry running (snoring). The closed high-chrome cast-iron impeller maximises efficiency and minimises wear.

Jones says: “We began by looking at how we could use the rotation of the water and the different flows that arise within the pump to eject the particles, preventing them from reaching the impeller neck. We discovered that a modified closed impeller and spiral groove combine to generate forces that reduce the accumulation of material. This is the principle behind Dura-Spin.

“Initial tests of over 100 hours of operation with 40% dry solids by weight showed that the new Dura-Spin design doubled durability under normal operating conditions. When the pump runs dry, the design can further increase the operational lifetime of the pump.

“In dry running (snoring) conditions, stones and other materials causing wear gather in the immediate vicinity of the pump impeller and there is insufficient water to lead the abrasive material away from the pump housing. Wear increases dramatically and, in the end, this affects the performance of the pump.

“If we consider how often de-watering pumps run dry, it is obvious that the new design has a great impact on the lifetime of the pump.”

These tests when performed versus a traditional de-watering pump give three times the wear resistance during ordinary pumping as well as snoring. The goal of optimum durability, which has characterised development efforts for the new pump series, has resulted in further improvements.

For example, in the new pumps, water is redirected in its onward flow from the pump housing in such a way that its impact on the casing is minimised. A rubber guide vane directs the flow of water, reducing wear on the internal walls of the pump.

“We have taken a holistic view of durability. We cannot base our solutions on passing the problem along. The new pumps will be more durable throughout the whole pump,” says Jones.

A single trimming screw within the hydraulics is also new and allows fast and easy impeller trimming for optimal performance sustained over time.

Performance is heightened further using a Plug-in seal versus the traditional seals of the Bibo range. The one-piece Plug-in seal provides faster, simpler replacement. Its design also protects seal surfaces during disassembly and mounting.

Unique to ITT Flygt is Spin-Out, a patented design to protect the lower mechanical seal and stop abrasive solids accumulating in the inner part of the seal chamber. The centrifugal force instead directs solids particles via a spiral groove back towards the pumps housing. It thereby helps to minimise wear and extends service life. To make the 2600 Series easier to use and maintain for end-users, the number of parts has been reduced by up to 50%.

Uniform design

A modular approach makes it simpler to remove and repair specific parts and a uniform design means the same principles are applied to service all six pumps. This commonality of parts reduces the amount of stockholding required at the customer end.

Clever additions like external oil and inspection plugs, and a screw-on junction box cover with a removable top covering electrical components, make the pumps easy

to check at site without having to take the whole outer casing off.

A new slim line design of the 2600 versus the wide base design of the Bibo broadens the de-watering applications in which it can be used enabling it to fit into narrow pits and pipes. An ergonomically designed and conveniently placed handle is a finishing touch to make the product easy to grip and manoeuvre around site.

Finally, new materials have been sourced for this range which differ to the Bibo yet retain the ability to pump highly abrasive liquids. On four of the new models, a stainless steel cooling jacket replaces cast aluminium.

In place of the Bibo’s galvanised steel, a stainless steel strainer and cooling jacket ensures corrosion and impact resistance and a high chrome cast-iron (suction cover) completes the look.

As one of the world’s leading suppliers of submersible pumps, Flygt’s engineering and service resources are available to support customers specifying and using this new range of innovative products. Flygt’s System Engineering Services (SES) team works closely with customers to advise them on the right pump for the right application.

In this field, Flygt can provide assistance to end-users and their consultants for an optimal solution.

It considers key criteria such as the full running costs incorporating energy and maintenance, ways to minimise these and maximise pump efficiency, to provide the correct pump selection.

During the full asset life Flygt technical and service teams remain available to the client. All facets of lifecycle cost are considered to guarantee a pump’s long life.

Jones concludes: “The 2600 Series builds on and incorporates all the experience we’ve gained over the years to take de-watering pumps to a new level.

“We will continue to invest in new technology and R&D to lead the way in this area and meet ever increasing customer demands for consistent performance over time and economy in all market sectors, including public utilities, construction and mining and industry.”

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