This is not the first time I have “beat up” on excess flow valves and the reliance on them as a “safeguard” in a PHA or process design. Both EPA and OSHA are on record stating their displeasure of claiming these valves as a safeguard. Now don’t get me wrong, these devices WORK and WORK WELL when they are DESIGNED, INSTALLED, TESTED, and MAINTAINED per the manufacturer’s requirements… and here lies the problem. These valves MUST be included in the PSI – Safety Systems with the engineering (i.e. sizing) documentation, as well as reside in the MI program for inspection and testing. Here is some language from one of the top manufacturer of these safety valves and we can see that these valves require a LOT of attention, which many facilities are lacking…