With the technological development of the Internet of Things (IoT), a wide variety of IoT-based monitoring systems have been developed in various domains. An IoT-based monitoring system provides an administrator with efficient management and information collection. Due to such advantages, the demand for monitoring systems in the gas industry domain has dramatically increased. In this paper, we propose two kinds of novel gateways and sensor nodes that apply an object identifier (OID) to monitor gas facilities. The proposed gateways and sensor nodes collect gas and environment data with various sensors and communicate with a monitoring server. If an exceptional event happens at the inspection site where our devices are installed, sensor nodes can take action by issuing control commands from the monitoring server. Moreover, we have also designed an OID that provides resources and devices in a gas monitoring system with a unique identification. By applying an OID to each message for transmission among sensor nodes, gateways, and monitoring servers, gas facilities and related devices can be accurately and safely managed. To evaluate the proposed devices, we properly installed our gateways and sensor nodes near operating gas facilities and verified their operation.