The hydrant pipeline network is designed as a looped buried system circling the fueling apron, to transfer aviation fuel from the aviation fuel depot to all aircraft parking area. The piping is in accordance with API 5L Gr. B, coated with polyethylene and lined with epoxy, consisting of buried 24”, 16”, 12” and 6” NB. Vents and low points have been provided to remove entrained air and accumulated contamination, respectively.

The sectional valve chambers are used to isolate or segment portions of the hydrant system for emergency maintenance or regular leak testing. The sectional valve chambers are equipped with motor actuated double block & bleed valves and pressure/temperature transmitters to monitor pipeline leakage. In addition, all monitoring functions are controlled by a computerized system called: Supervisory Control and Data Acquisition System (SCADA). Sectional valve chambers and the equipment installed within receive regular inspection and maintenance.

The function of the hydrant pit valve is to facilitate aircraft refueling at aircraft parking stands by connecting the underground hydrant system to the hydrant dispenser vehicle, as well as to safely control the flow of fuel to the aircraft. The hydrant pits valves are installed underneath the apron and are equipped with dual air pilots. Moreover, the hydrant pit box is of an environmentally friendly design, such that it minimizes the ingress of ground water and also prevents the egress of spilt or leaked fuel. All hydrant pit valves undergo regular and comprehensive inspection, functional testing and performance testing.

In order to protect the buried hydrant pipeline network from corrosion, an impressed current cathodic protection (CP) system is implemented. The buried pipeline network is electrically separate from other metallic structures to prevent electro-chemical interaction. Regular preventive maintenance of the CP system is carried out to assess and mitigate problems before they can affect pipeline integrity.

The Hydrant Emergency ShutDown System (ESD) is actuated via hardwired buttons provided at every aircraft parking stand; a total of 139 buttons. The system continuously monitors for an ESD signal originating from the various ESD buttons, the signal is then transferred via fiber-optic cable to SCADA. In case of an emergency, pressing the ESD button will cause the segregation of the hydrant pipeline network, restricting fuel shutdown to that vicinity, thus allowing other areas of the airport to continue to operate. The ESD is tested regularly to ensure system performance.

Tightness Monitoring System (TMS) examines the hydrant pipeline network for leakages using a statistical data analysis technique and pin-point the leakage location by measuring pressure at various points along the pipeline. The system has demonstrable accuracy of 0.04 litres/hr/m3 and checks the leak location with the accuracy of +/-100 Meter. more...

In order to protect the buried hydrant pipeline network from corrosion, an impressed current cathodic protection (CP) system is implemented. The buried pipeline network is electrically separate from other metallic structures to prevent electro-chemical interaction. Regular preventive maintenance of the CP system is carried out to assess and mitigate problems before they can affect pipeline integrity.