Bedford Pumps' stormwater pumps at Yorkshire Water's Elland Lowfield pumping station.
Bedford Pumps' stormwater pumps at Yorkshire Water's Elland Lowfield pumping station.

Bedford Pumps have provided two ATEX-compliant suspended bowl storm pumps for the Elland Lowfield pumping station as part of Yorkshire Water’s continued investment in infrastructure.

Bedford Pumps designs and manufactures specialist pumping plant for the water, wastewater, flood control and dockyard industries. Storm pumps are frequently installed in wastewater pumping stations because heavy rainfall can have a significant impact on the sewerage network often resulting in intermittent discharges of diluted sewage during and after storm conditions. 

Additional challenges

Bedford Pumps’ stormwater pumps are designed to keep stormwater away from homes in the area during times of heavy rainfall. In the case of the Yorkshire Water application, there were the usual requirements of handling solids, grits and rags, but also some additional challenges. 

The existing structure proved problematic as the opening for the pumps was too small for the increased duty requirements.  Bedford Pumps was able to design a pump to suit the structure, without losing any performance or hydraulic efficiency.  This avoided the additional civil work, which saved substantial capital cost.  In addition, prior to pump installation, sole plates were installed, which eliminated the need for levelling on initial or subsequent maintenance installations and conformed to gas tight sealing requirements. 

Critical reliability

Wastewater storm pumps need to perform reliably when required or there is a real possibility of raw sewage overflowing the station and flooding nearby residential and business areas.  Due to the critical nature of these storm pumps, Bedford Pumps designed and supplied the pumps with shaft enclosing tubes, ensuring the critical water lubricated bearings did not suffer premature failure due to running in wastewater.   A separate flushing system was supplied by Bedford Pumps comprising; duty and standby pumps; a control panel; all necessary valves; fittings and flow switches mounted on a common base skid. 

Double seals

Another area of concern on wastewater applications is the mechanical seals.  If the liquid is clean it is normal to use the pumped liquid to provide the lubrication but in the case of storm pumps in a wastewater treatment works, the pumped liquid is contaminated and therefore not an appropriate liquid to lubricate the seal faces.  To overcome this problem, Bedford Pumps supplied the pumps with double seals using a siphon system, ensuring a clean flow of liquid lubricates the mechanical seal faces and giving the maximum mean time between failure for the mechanical seals.