High reliability and real-time performance are main research challenges in Industrial Wireless Sensor Networks (IWSNs). Existing routing protocols applied in IWSNs are either overcomplicated or fail to fulfill the stringent requirements. In this paper, we propose a reliable and flexible Received Signal Strength-based routing scheme. Our proposed solution can achieve a seamless transition in the event of topology change and can be applied in different industrial environments. The simulation results show that our solution outperforms conventional routing protocols in both reliability and latency. Furthermore, the result also proves that the changes of the network topology have no impact on data transmissions of other nodes by our scheme, whereas conventional routing protocols are shown to fail to recover the network in a short time. Finally, due to dynamic weighting mechanism, the proposed scheme is verified to achieve significantly higher reliability in scenarios with obstacles and avoid installation troubles, compared to location-based flooding scheme. Thus, our proposed scheme is considered to be more suitable for IWSNs than other routing protocols.