Description of transmission system

The gas transmission system of the Republic of Croatia consists of international, main, regional and connecting gas pipelines and the facilities on the gas pipelines with the operating pressure of 75 and 50 bar, as well as the measuring-reduction stations (MRS) of different capacities. By the existing structure and territorial expansion of the gas transmission system the technical-technological aspects are harmonized with needs of the transmission system users, for the purpose of providing secure and reliable transmission and delivery of gas, along with optimization of maintenance and operation costs.

Preconditions for secure and reliable gas transmission and fulfilment of contractual liabilities towards the transport service users have been provided by continuous transmission system supervision, remote and local management of technological facilities, proper and timely preparation of the system for the special operating conditions, analysis of system conditions, forecasting system conduct, timely forward of information on the system status as well as the status of equipment and system elements, physical supervision of technological facilities and their systematic, preventive and corrective maintenance.
 
The transmission system of the Republic of Croatia operated by the transmission system operator Plinacro Ltd consists of the following:

• gas pipelines:
• 945 km of gas pipelines, maximum operating pressure 75 bar, diameter from DN 200 to DN 800 mm,
• 1571 km gas pipelines, maximum operating pressure 50 bar, diameter from DN 80 to DN 500 mm,
• gas nodes:
• entry measuring stations:
• 2 interconnection measuring-reduction stations at the connections with the transmission systems of the Republic of Slovenia and the Republic of Hungary  
• 7 entry measuring stations at the connections with the natural gas production plants
• 1 entry measuring station at the connection with the underground gas storage Okoli exit measuring-reduction stations:
• 156 MRSs at which are connected 37 distribution systems and 24 end buyers of gas and at which measuring of gas volumes and delivery of gas to the users, under contracted terms, is performed  
• launching and receiving scraper stations:
• block stations
• cathodic protection
• system of fiscal metering remote reading
• 156 communication devices with associated computer and program equipment
• Remote control, management and data collection system (SCADA)
• communication system (fibre optic, radio)
• computer simulation system (SIMONE)
• system for transmission system capacity management (capacity booking, nominations, allocation of measured volumes, reporting)

Basic information on the transmission system:
 

Transmission system of the Republic of Croatia
Number of transmission system operators	1
Total gas pipeline length of the transmission system	2 662 km
Interkonekcije / operator transportnog sustava:	Rogatec / Plinovodi d.o.o. (SLO) Drávaszerdahely / FGSZ Ltd. (HU)
Interconnections / transmission system operator:	Okoli / Podzemno skladište plina d.o.o.
Domestic production / gas producer	UMS CPS Molve / INA - d.d. UMS Etan, Ivanić Grad / INA - d.d. UMS PS Ferdinandovac / INA - d.d. UMS PS Gola / INA - d.d. UMS PS Hampovica / INA - d.d. UMS Terminal Pula / INAGIP d.o.o.
Number of end users connected to the transmission system:	Total: 34
Number of distribution systems and distribution system operators:	No. of connections 153         No. of DSO:  37
Broj zona uravnoteženja:	1
Transported quantities (historic data)	(u GWh) 2013:  28.715 2012:  31.259 2011:  31.679 2010:  32.425 2009:  30.147

Entry and exit points, operators of connected systems, nominal pressures 
Map of transmission system