Centralized monitoring and control system for natural gas transmission stations

During 2008-2009, Hasel Industrial has developed under the name “CENTRALIZED MONITORING AND CONTROL SYSTEM FOR NATURAL GAS TRANSMISSION STATIONS” a modern and complex product designed for automation of gas transmission stations. The product includes both the physical hardware part (process instrumentation) and the software application part, integrated in the control and data aquisition systems to assure a safe and automated control.

Implementing this system ensures centralized monitoring and control of new and existing equipment: on/off valves, control valves, odorisation equipment, PIG launching and receiving installation, methanol injection system, gas heating system etc. Also it ensures data acquisition, data analysis and logging (pressure, temperature, flow), enabling easy access from SCADA systems. In order to fit the requirements of gas transmission stations, the system is compatible with a wide range of automation devices, so it is possible to integrate various types of valve actuators, transducers and flow meters. In the eye of the human operators all of the field devices are completely transparent, this means that they are able to operate and visualize the state of technologically different valve actuators using the same user interface elements, for example consider the case of a gas transmission station which has in its pipeline structure electric, pneumatic and also hydro-pneumatic valve actuators. The process values can be acquired through 4-20 mA unified signal combined with HART protocol, or by using other field communication protocols (Modbus RTU, Profibus DP, Foundation Fieldbus, LonWorks), or even wirelessly through wireless gateways.

The central element of the “automation product” is the software application that aquires and processes the data of actuators and transducers, developed by the company’s software development team. Thanks to the software components, the final product can be easily configured to fit any structure of gas transmission stations. The product has been registred in 2009 at the Romanian Copyright Office and has been used for the first time in the end of 2009 for automation of Onești Gas Transmission Station of the Romanian National Gas Transmission Company.

The software application comes with the above listed main features:
a. Graphical user interface with tri-dimensional diagrams, as seen in Fig. 1., showing the state of valves, the process values and allowing the control of valve actuators.
b. The possibility of intruducing the state of manual valves.
c. Simultanously showing in the same screen the required information and executing open-stop-close commands based on user credentials (username and password).
d. Every command and the related information (timestamp, operator) is logged in the database of the software, but if the command was performed locally, the application automatically saves the events of state changes.
e. Automated report generation for given periods of time.
f. Graphical visualization of process parameters
g. Symbolic representation of valve position and valve states (remote-off-local, fault).
h. State parameters of valve actuators:
• open-close limits
• torque limit
• running state (closing, opening)
• actual position in %
• actual torque value in %
• fault conditions (phase lost, overheated, jammed)
i. Pressure, temperature and flow regulation using controllers implemented in the programmable logic controller of the station.