DESMI Ocean Guard

Ballast Water Treatment Systems

DESMI Ocean Guard develops ballast water treatment systems for the marine industry.

The company's systems have set industry benchmarks for low-power consumption and reliable performance in challenging water conditions.

Optimised ballast water treatment system

Rayclean is a type-approved ballast water system, which uses mechanical filtration and UV radiation.

Mechanical filtration is performed using an automatic back-flushing filter developed especially for Boll & Kirch ballast water. It employs a screen filter with a 30-micron wire mesh.

UV treatment takes place in a specially designed and optimised UV reactor that has a treatment rated capacity (TRC) of 300m³/h. System flow rates up to 3,000m³/h are obtained by installing more UV reactors in parallel.

The RayClean system uses highly effective, low-pressure UV lamps that reduce the system energy consumption between 30% and 50% compared with mid-pressure lamps.

Fully automated treatment for ballast water

Crew members only need to start and stop ballast operations, with the rest of the RayClean system's operation being fully automated.

The RayClean system copes with extremely challenging water conditions by automatically reducing water flow through the system.

While other UV systems have to give a low UV transmission warning, the RayClean system can continue treatment in compliance with discharge standards by reducing the flow rate.

Reliable ballast water treatment systems

System development and testing have provided a reliable solution that will work with any level of water salinity or temperature.

DESMI Ocean Guard has also tested its systems in freshwater conditions, and at extremely low UV-transmission.

This provides solid evidence that when other ballast water treatment systems reach their limit cold water or low UV-transmission, DESMI Ocean Guard systems remain functional.

System component delivery for vessels

DESMI Ocean Guard delivers ballast water treatment systems as individual loose components to facilitate integration for retrofit projects or larger systems.

Systems can also be delivered skid-mounted, the best option for small / mid-sized systems and new vessels.

Alternatively, systems can be provided in a container, requiring only a connection to a power supply, and a ballast water inlet and outlet.

Ship inspection and engineering services

DESMI Ocean Guard's talented engineers can inspect vessels to provide feedback on the best possible location for retrofit ballast water treatment systems.

The company can use 3D scanning to prepare a 3D CAD model, which will give an accurate indication of how the system will look when installed aboard vessels.

This ship inspection service will allow clients to plan ahead and avoid possible collisions with equipment such as ladders, piping and stiffeners.

Installation, commissioning and servicing of ballast water systems

DESMI systems are installed and commissioned by one of the companies' supervisors, alongside a crew of experienced workmen, and DESMI collaboration partners.

The company offers a complete service agreement for its systems, including regular inspections and maintenance work.

About DESMI Ocean Guard

In 2009, ship owner AP Moller-Maersk, pump manufacturer DESMI, and water treatment specialists UltraAqua established DESMI Ocean Guard.

By combining the knowledge of these three companies, it has been possible to develop ballast water treatment systems that meet International Maritime Organisation (IMO) discharge standards.

The systems also take into consideration the special concerns and issues related to installation and daily operation on-board vessels.

DESMI Ocean Guard is now owned by DESMI A/S.

Available White Papers


DESMI Ocean Guard CompactClean: Ballast Water Management System 29 September 2017 DESMI Ocean Guard A/S is part of the DESMI Group, which was founded in 1834 by Henning Smith and is one of Denmark's oldest companies.


DESMI Ocean Guard RayClean 15 December 2015 RayClean is the leading ballast water treatment system in the marine industry, with unrivalled treatment performance and the lowest energy consumption in its class.