Flood Defence Pumps

Bedford Pumps Ltd, one of the world’s leading manufacturers of high-capacity flood defence pumps, has selected Thordon Bearings water lubricated SXL bearings for a new pump design developed for the Islington Pumping Station, in King’s Lynn, England.

This project will see four fish-friendly land drainage and flood control pumps installed at the new 16,000 l/s (253,605 US gal./min.) capacity pumping station which, when commissioned, will protect a 6000ha (23m2) area of low-lying fenland.

The existing pumping station, built in 1959, had reached the end of its service life and will be demolished following the construction of the new pumping station.

Canadian based Thordon Bearings, a pioneer in elastomeric polymer materials, supplied eight 200mm (7.9in) inside diameter fully finished water lubricated SXL bearings, in a contract that marked the first application of a Thordon bearing in a Bedford pump.

Alix Macdonald, Engineering Manager, Bedford Pumps, said: “We have created a brand-new type of axial flow pump to offer better efficiency, better solids handling, and enhanced environmental protection compared to other concrete casing pumps of comparable size.

We found the Thordon product to be the best solution for large diameter vertical shaft bearings. The water lubricated elastomeric polymer material allows the impeller to run at much tighter tolerances, improving overall efficiency, maintainability and reliability.”

Macdonald said that “competitive pricing, high quality material and a long-life expectancy” were also important factors in the procurement decision.

“The material is very easy to use, and easy to machine. And then when it comes to installation, we can freeze fit, press fit or bond fit, so there are some options there too.”

Axel Swanson, Business Development Manager, Thordon Bearings, said: “The SXL bearing is the market leader in product lubricated vertical pump bearings due to its durability, resistance to abrasion, shock loading and vibration. Wear life and performance are the biggest advantage to using Thordon materials.”

To achieve “fish-friendly” status, a key requirement for pump station owner Kings Lynn Internal Drainage Board (IDB), Bedford Pumps designed a 4000 l/s (63,401 US gal./min.) pump capable of allowing fish, migratory eels and other marine life to pass through unencumbered.

A complementary intake was also designed which offers significant advantages over a standard ANSI type 10 intake, such as allowing the water levels to be drawn down to half the minimum submergence when compared to the type 10 design. “This intake significantly reduces the pumping station’s footprint and the deep excavations typically required,” said Macdonald.

Chris Simmons, Sales Manager, Duwel Group, Thordon Bearings’ UK distributor which also provided front end engineering assistance, said: “As a new customer for Thordon and Duwel, it is a privilege to be involved not only in an important flood defence project but also in the development of a new range of Bedford pumps.  We are proud to have supplied Thordon bearings to what is a unique, ecologically safe pump. It is an important project and important piece of kit.”

Macdonald added: “We will definitely look at using Thordon’s bearings in the future for similar pumps. The workshop staff gave Thordon SXL bearings a very high rating based on how easy they were to fit with dry ice.”

At full capacity, the Islington Pumping Station will be capable of pumping 1.4 billion litres (369 billion US gal) of water per day.