Hydro Innovations installed a Gorman-Rupp self priming centrifugal pump at the Moe Wastewater Treatment Plant to improve pumping efficiency.
For over 14 years, the Moe Wastewater Treatment Plant was effectively and successfully processing sewage using submersible pumps. Located in Gippsland, Victoria, the medium-sized plant serves a population of 22,000 and manages an average daily flow of five mega litres.
When the plant’s two submersible pumps at the inlet station began blocking up with increasing regularity in 2010, the resulting ineffectual performance began to impact on the efficiency of the plant.
Adrian Harper, Senior Engineer Wastewater Treatment Group, Moe Wastewater Treatment Plant explained that the submersible pumps were choking about once a fortnight between February and the start of December 2010, and were no longer capable of effectively handling the increasing flows and rags.
The engineers tried to deal with the problem by calling in their maintenance contractors to isolate the obstructed submersible pump, lift it using a crane and then clean it before lowering the pump back into the wet well.
According to Adrian, the entire exercise was time consuming, inconvenient and expensive, and negatively impacted on the plant’s performance. Apart from about $27,000 spent during the period just on getting the contractors in to clean the pumps, the problem also created OH&S headaches as it required the continual lifting by crane and cleaning of an 800kg submersible pump. The whole process increased the risk of accident when the plant was committed to improving its safety profile.
Keen to find a permanent and effective answer to the choking pump problem, the wastewater treatment plant invited Hydro Innovations to assess their dilemma and provide a workable option. After exploring the site and the needs of the plant, Hydro Innovations suggested installing an above ground Gorman-Rupp self-priming sewage pump.
An option study initiated by the plant to evaluate Hydro Innovation’s solution as well as explore the pros and cons of a self-priming pump versus a submersible pump with a cutter impeller, confirmed that a self-priming pump would be a workable solution.
To convince themselves completely on the suitability of the self-priming pump for the application, Adrian requested for a pump trial for three months. Hydro Innovations provided the plant with a Gorman-Rupp T8A3S-B above-ground self-priming centrifugal pump in December 2010. By mid-December the pump was installed and in use.
Following the three-month trial period, the plant was impressed with the Gorman-Rupp pump’s performance and purchased the machine. Another Gorman-Rupp self-priming pump was added subsequently. The plant now confidently runs on two Gorman-Rupp self priming pumps instead of three submersible pumps.
Key features of Gorman-Rupp T8A3S-B self-priming centrifugal pumps:
- Purpose-built sewage pump fitted with an aggressive self-cleaning wear plate
- Wear plate specifically designed to handle stringy material preventing clogging
- Can be easily and quickly unclogged by a single person without a crane if any choking occurs via removable cover plate and without disconnecting piping
- Unique collar and adjusting screw allow for incremental adjustments of wear plate clearance
- Users can adjust clearance between the impeller and wear plate without having to pull it apart or handle contaminated components
- Collar locks in place maintaining the clearance setting and enabling operators to maintain peak operating efficiency
- No money wasted on cleaning the pumps fortnightly
- Eliminates downtime associated with cleaning as well as the inconvenience
- Allows quick cleaning if required, above ground to eliminate OH&S issues
- Motor can be replaced if a malfunction occurs