Effective data exchange among the diverse stakeholders participating in a process plant project is an important issue. ISO 15926 is an international standard to support sharing and integrating of process plant data. iRINGTools is an ISO 15926-based tool used to exchange plant data. To exchange plant data using iRINGTools, the mapping between the data model of a commercial system and ISO 15926 should be preceded. To accomplish this, types and properties of equipment and materials used for plant design should be predefined and these data should be represented as user-defined reference data complying with ISO 15926. Besides, the user-defined reference data should be serviced by a reference data server such that iRINGTools searches reference data from the server and utilizes the data for the model mapping. In this paper, we present a method to construct a reference data server and use it for the model mapping in iRINGTools. The proposed method is verified through experiments of exchanging specifications data of equipment and materials using iRINGTools.