Gas Authority of India Ltd. (GAIL), India’s principal gas transmission and marketing company was set up by the Government of India in 1984 to create an infrastructure for sustaining India’s development of the natural gas sector. GAIL is responsible for integrating all aspects of the Natural Gas value chain (including Exploration & Production, Processing, Transmission, Distribution and Marketing) and its related services. While GAIL is the responsible entity for these activities it is not a monopoly, having a market share of just over 70% of the gas transmission and marketing business in India.
With the endeavor to gasify the northwestern states, the major natural gas pipeline known as the HVJ pipeline (Hazira-Vijaipur-Jagadishpur) was constructed and became operational in 1991. The 3400 km plus pipeline extending northeast from Gujarat State, provides natural gas to all the gas based power plants, fertilizer plants, and industries along the entire West-North corridor of India. The HVJ pipeline system consists of receiving/dispatch terminals for the supply of metered gas, compressor stations for boosting the pressure of gas, and a SCADA system for monitoring the pipeline operation.
The continued growth in gas demand necessitated the addition of new compressor stations in Jhabua and Vijaipur. The compression duty was supplied by Rolls-Royce with (3) RB211 (35,000 Bhp) gas turbine pipeline compressor sets for each site. Rolls-Royce supplied the Unit Control Panel for each turbo-compressor set and contracted United Controls Group to design and manufacture the Station Control Panel for each site.
The GAIL specification called for extended redundancy to ensure a high degree of reliability within the control System. The Station Control Panel, one for each Station, included:
- Redundant Allen-Bradley ControlLogix Controllers and Power Supplies
- Redundant PLC Ethernet Modules to Redundant Ethernet Switches
- Redundant fiber Hiper-Ring Ethernet Switches
- Redundant Serial Links to Station DCS system
The Panel also included full Marshalling terminations (disconnect terminals), galvanic isolators for I/O to the control panel, diagnostic digital input modules, integration of compressor surge control system, and serial communications to new Fuel Gas Flow Meters. The integrated HMI screen development integrated with the Unit Control Panel HMI system.
Key functions within the Station Control functions included yard valve control, the fuel gas conditioning skid controls and the plant air compressor controls.