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Marine Class Certified Bronze Vertical Inline Centrifugal Pump for Seawater Ballast Transfer

Azcue VM 50/20 marine vertical inline centrifugal pumpUrgent Replacement for a Ballast Water Pump

The ballast system is crucial on a marine vessel and must have a reliable pump. The ballast tank holds varying quantities of water to provide stability to the boat depending on sea conditions and onboard weight. There are various tanks located onboard, a pump is used to transfer water between these to distribute weight. 

Typically referred to anti-heeling pumps, these are required to produce high flow rates at low to medium pressures. It is common for marine class certification to be necessary while also ensuring the materials are resistant to corrosion from the fluid and environment. 

A vessel operators’ current pump had failed, and they needed a replacement urgently. The existing unit was very old and limited information was available as the nameplate had corroded badly. After discussions with the chief engineer, we were able to obtain photos of the pump and installation, while also ascertaining the pipework bore, flow rate and pressure required. There was limited space available in the room where the unit was located, therefore it was crucial that it was vertical inline and did not exceed the flange to flange dimensions of the existing unit. 

North Ridge Pumps Corrosion Resistant Bronze VM 50/20 Vertical Inline Close Coupled Centrifugal Pump

The ballast system needs a flow rate of 35m³/hr at 4 bar to function correctly, we therefore selected our VM 50/20 vertical inline close coupled centrifugal pump with bronze casing and impeller. Bronze is non-ferrous and the perfect material for sea water, it is corrosion resistant and more cost effective than stainless steel. This model is mounted vertically with the motor situated on top to reduce the footprint. It has a back pull-out design that allows the motor to be removed while the pump is still connected to the pipework, this lets the engineers have easily access to the internals for maintenance, ultimately saving time and costs. 

We had the pump marine certified by Lloyds during testing as per the customer’s request, this range can be class certified by other bodies such as ABS, DNV and Bureau Veritas if needed. We can also install either an electric or air driven priming system to make a self-priming pump for installations requiring a suction lift. 

marine certified bronze ballast pumpBelow are the specifications of the sea water ballast pump that was supplied:


VM 50/20 Vertical Inline Close Coupled Centrifugal Pump


Bronze casing and impeller, stainless steel 316 shaft.

Flow rate:







7.5Kw, 2900RPM



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