Transmission Pipeline Systems


We are involved in the construction of onshore Transmission Pipeline that receive natural gas from offshore pipelines. These systems (which include emergency shutdown valve stations, receiving stations, off-take stations, line valve stations and launcher/receiver stations) then transport natural gas to factories and power plants. A diagrammatic representation of a typical Gas Transmission System is as shown below. In addition, we are involved in various pigging operations and caliper and intelligent pigging.

 



Key systems implemented in these projects include:

a) Supervisory Control and Data Acquisition System ("SCADA system")
The SCADA system is a system of supervisory control and monitoring panels which enable the control of equipment to be done from a remote location and the collection of data and feedback of signals from instruments and equipment. It provides real-time graphical updates and allows remote monitoring and control of all the off-take stations (pressure regulating and metering stations) and line valve stations within the pipeline network.

b) Leak Detection System
The leak detection system is a computerised real-time monitoring system which consists of field instruments such as pressure transmitters, temperature transmitters and flow transmitters installed at strategic locations to detect any leakages in the underground piping network.

c) Flow Control System
The flow control system typically consists of pressure regulating valves, active pressure regulators and flow control valves with actuators. The system, controlled by a programmable logic controller, regulates pressure and flow within the pipelines to ensure that they are within the allowable pressure limits.

d) Cathodic Protection System
The cathodic protection system protects underground steel pipelines from corrosion through electrolysis. Dependant on a permanent or sacrificial anode system, the system may consists of AC/DC rectifiers and zinc earthing electrodes and utilises an external power source which provides protective current to moderate corrosion activity.