Industrial wireless sensor and actuator networks (IWSANs) offer significant advantages to industrial automation. However, high-reliability demands and hard communication deadlines pose challenges to its practical applications. To achieve this goal, flooding is considered as a promising approach due to multipath diversity and simplicity. In this paper, an enhanced version of REALFLOW, a flooding-based routing protocol for IWSANs is presented. Compared to the original REALFLOW, network management and network stability are improved. REALFLOW is compared with four other flooding protocols via simulations. The simulation results show that REALFLOW has better performance in terms of reliability and consecutive transmission errors when considering deadlines. Compared with normal flooding, REALFLOW achieves comparable reliability performance with decreased redundancy. Measurements from a prototype implementation conducted in an industrial manufacturing workshop reveal that high-reliability and low-application failure rates can be achieved, giving more confidence in providing reliable wireless sensing and actuating for industrial automation.