The New Zealand Navy was looking to extend the service life of the helicopter re-fuelling systems on it's ageing fleet of Anzac frigates. HAAR had designed and supplied the original refuelling system when the ships were built (up to 25 years ago), and with the advances in technology it was decided to upgrade the fuel system filtration and water detection.
A new Water in Fuel detection system was designed based around a AFGUARD sensor and a RMA42 measurement relay. These provided signals into the existing Siemens PLC to shutdown delivery at pre-determined water-in-fuel levels.
The existing Siemens program was modified to replace the defunct differential pressure gauses signals with the new water detected inputs. The Siemens HMI was also modified to present the new alarm messages to the operator.
The new AFGUARD water in jet fuel detectors were plumbed into the existing fuel delivery lines, and the new PLC & HMI programs loaded in whist the ship was in for scheduled maitenance.
The whole refuelling system was run through it's delivery modes, and the water in fuel level simulated via a 4-20ma injector. System behaviour was tested to ensure that when water was detected the system prevented delivery of contaminated fuel the aircraft.
In total 6 NZ Navy ships were upgraded, HAAR and Wagtec are now looking to implement similar changes to the Australian Navy vessels next year.