Centrifugal Pump for Marine Grey Water Discharge Onboard Ship

An Overview of Marine Grey Water

Three main types of wastewater are produced onboard marine vessels, these are typically described as grey water, black water, and bilge water. All three are distinct types of waste and are therefore stored in separate holding tanks for discharging later.

Grey water is only mildly contaminated, normally containing waste from sinks, showers, laundries, and kitchens (galleys), this does not typically contain solids. This can be recycled and reused for other purposes that do not require fresh water, such as toilet flushing. Black water is polluted with toilet waste and contains solids that include faecal matter and tissues. Finally, bilge water is contaminated with oil, this can originate from maintenance work on machinery and leakages.

Enquiry from a UK Ship Repair Yard for a Grey Water Discharge Pump

A UK ship repair yard required a replacement for an existing grey water discharge pump installed on a ship that was undergoing maintenance in dry dock. The current pump was beyond economical repair and therefore a complete new unit was necessary. Luckily, the nameplate was intact, and we were able to obtain the performance information for flow rate and head/pressure.

Selection of our Cost Effective XCN100/160 Centrifugal Pump

After studying the performance information, photos of the installation and dimensions, we selected our XCN100/160 centrifugal pump fitted with a 7.5Kw, 1750RPM motor. This will perform the duty required of 145m³/hr at 13.5m head, the 4 pole slower motor means that the life of the wearing parts is prolonged and will reduce the cost of spare parts and maintenance in the long run.

The 125/100mm flange connections fit the existing pipework perfectly and will make installation a simple process for the engineers at the repair yard. To prolong the life of the pump further, we installed a bronze impeller with the cast iron casing, the bronze will help to resist corrosion over time.

We can have marine bodies such as Lloyds, DNV or ABS witness test and certify our pumps if necessary, however this was not required by the customer on this occasion. We also have the option to manufacture our centrifugal pumps vertically for space saving and in various materials including, cast iron, bronze, stainless steel, and duplex stainless steel.

See the below description of the centrifugal pump that was delivered: