A NSW Coal Fired Power Station had been having issues with their pumps in the waste water and waste chemical area of the plant.
The very corrosive liquid was “eating away” at the pumps’ cast iron casings and moving parts at a fast rate. In some cases even the stainless steel components were unable to stand up to the very aggressive nature of the pumped liquid.
Why Did The Power Station Team Select A Gorman-Rupp Wastewater Pump?
Hydro Innovations were asked to investigate material options that could be used in the pump construction to resist the corrosive effect and prolong pump life.
Internally coating the casings was considered, however was deemed to be potentially ineffective as machined surfaces with-in the pump could not be coated, therefore still exposed to the corrosive liquids.
Finally it was decided to offer pumps constructed entirely from duplex stainless steel (CD4MCu).
CD4MCu (SS2605) is a duplex stainless steel with a PREN [Pitting Resistance Equivalent Number] of 32.1, making is more than 17% more corrosion resistant than SS316. It also has a Brinell hardness of approximately 300, making it much harder and abrasion resistant than SS316.
CD4MCu is widely used in the pump industry where applications are both abrasive and corrosive.
The Benefits
- High corrosion and pitting resistance
- Harder for better abrasion resistance
- Higher strength than standard stainless steel
- Improved ductility and weld-ability
- Better resistance to embrittlement
The Results
It was ultimately decided to upgrade from the existing stainless steel fitted cast iron pumps to the Gorman Rupp U6B65S-B self-priming pumps, which have casings and wearing parts cast in CD4MCu.
Not only did this choice present a pump with excellent corrosion resistance and the necessary duty needs to meet the power station’s brief, but also provided a pump unit with easy access and maintenance & service requirements, durability, and very importantly, minimum exposure to the pumped liquid by operators.
4 x Gorman Rupp U6B65S-B have now been installed over the last two and half years with all four units meeting wear and reliability expectations.
For any further information on the full range of Gorman Rupp pumps for waste water, sewage, heavy industrial (including fuel) and manufacturing applications, please contact Hydro Innovations or check-out our website at www.hydroinnovations.com.au