Project Focus: Pumping station upgrade for Stillingfleet
When the Ouse and Derwent Drainage Board decided to update Stillingfleet surface water pumping station, installing new submersible pumps by crane proved a challenge
by Bryan Orchard
Working on behalf of the Ouse & Derwent Internal Drainage Board, pump supplier AxFlow has installed two new submersible Bedford pumps at the Stillingfleet Surface Water Pumping Station. The two pumps removed from service are also being overhauled. The purpose of the pumping station is to lift surface water which can no longer drain by gravity into the nearby beck because mining subsidence has lowered the surface ground level. The pumping station was constructed by the British Coal Corporation in the early 1990s as part of its mining remediation plans.
The reason for the installation of two new pumps was that high moisture readings were being recorded within the pump linings containing the electrical equipment. “This was causing an operational concern,” reports Mark Redgrove, AxFlow’s Technical Support Manager. “The pumping station is equipped with two large 800mm rising main storm and two 600mm rising main dry weather pumps. To fix the problem the pumps needed removing; however the pumping station required its pumping capacity to be sustained. The solution was to purchase two new submersible Bedford pumps which could replace the existing ones when they were removed. We were called to remove the old Bedford SB pumps and install the new pumps.
“Logistically, at first it appeared to be a straightforward job to remove and replace the pumps using scaffolding. The scaffolding is usually erected inside the wet well with a crane being used for removing and replacing the pumps to be changed. However, installing scaffolding in the pump wet well was not practical. This was because of the limited space along with the fact that the pumping station wet well was not totally sealed from the flows. The rising water levels requiring one pump running on and off to keep the level down,” says Redgrove.
In view of this, the potential practical options and health and safety implications of a confined space were considered as to how safely the work could be carried out. The option to be progressed required the utilisation of a man riding basket suspended in the wet well from a crane because of the constrained area and conditions. This made it necessary to have two cranes on site, one for lifting the pumps and a second crane for operating the man riding basket. According to AxFlow, it needed very careful planning and control to get both the man riding basket in place to position the pump lifting tackle and to carry out the pump removal and installation works with the two crane jibs working in such a small opening.
“Our plan was to remove the old flange bolts and pumps and reconnect the new pumps to the existing pipework with new bolts,” continues Redgrove. “The larger pump was standing on three feet on a concrete platform in the wet well and with the removal of some of the bolts the weight of the pump (4 tonnes) tended to pull it away from the flange on which it was fitted, putting the pump at risk of falling into the wet well. This was addressed by leaving some bolts in place until it was actually ready to lift.”
The job of removing the old pumps and installing the new pumps took AxFlow three days to complete. The work however has continued, as following the refit, AxFlow were asked to take the old pumps to their Huddersfield Service Base for inspection.
Redgrove continues: “We now have the pumps at our base and having stripped them down we have found that they were in pretty good condition, even after 25 years of service. However, some oil and water has got into the motor windings, this appearing to be caused by perishing cable glands which can be relatively easily rectified. We further looked at replacing the usual components that can be subjected to wear, including bearings and mechanical seals and washed out the stator windings and reassembled the pumps. The impellers were in good condition as they clearly had a relatively easy life, even though they are in a high profile pumping station and over the years had been subjected to high levels of continuous operation.”
The two original pumps still operating at the Stillingfleet Pumping Station will be removed in the future to be replaced with the two overhauled pumps at AxFlow’s Huddersfield workshops to finalise the current work on the pumping station.
- Project Focus: Pumps critical to River Clyde flood prevention scheme The installation of a new pumping station in North Renfrewshire has been central to a scheme to protect 300 homes and... Read More >
- Protecting Your Pumps With pumps being among a water company's most critical assets, screens and automated trashrakes have a vital role to play... Read More >
- Scottish Water cuts pump blockage costs A new device designed to stop wastewater pumping stations (WwPS) being blocked as a result of ragging is paying dividends... Read More >
- Ending the nightmare of wet-wipe pump blockages An ingenious device developed in partnership with Scottish Water promises to reduce wastewater pump maintenance by... Read More >
- Peristaltic pumps prove the right dose for Welsh Water Switching from diaphragm to peristaltic pumps for chemical dosing helped Dwr Cymru Welsh Water save Opex costs while... Read More >
- In Depth: AODD pumps Air Operated Double Diaphragm (AODD) pumps are an interesting seal-less, displacement alternative to centrifugal pumps.... Read More >
- Overpumping solution helps Anglian sludge management When routine maintenance was required on business-critical sludge assets at Anglian Water's Caister WRC, a temporary... Read More >
- Interview: Steve Schofield, Chief Executive, BPMA Never mind Brexit - the UK government needs to step up in its enforcement of current directives, says Steve Schofield,... Read More >
- Supply Network Manager Starting salary: Grade SF £30,767 - £41,226 Job description: Looking for your next career move in water supply? If so, we may have a fantastic... Read more here.
- Repair and maintenance ganger (team leader) Taunton Location: Taunton Starting salary: Dependent on experience and training certificates, plus standby allowance and call out Package: 45... Read more here.
- Repair and maintenance ganger (team leader) Yeovil Location: Yeovil Starting salary: 26,520 - 28,560 salary dependent on experience and training certificates, plus standby allowance and call... Read more here.
- Repair and maintenance ganger (team leader) Cossington Location: Cossington Starting salary: £26,520 - £28,560 salary dependent on experience and training certificates, plus standby allowance... Read more here.