Did you know that liquid trim valves can be certified for vapor?
There is often confusion around the required trim and certification when selecting a new safety-relief valve. For example, when there are both vapor relief scenarios and liquid relief scenarios, is a dual-certified PRV required? What about when the service is liquid but the controlling scenario is vapor? In the past, we have recommended “dual-certified” PRVs when there are both liquid and vapor relief scenarios, but these valves can be difficult to obtain or could have long lead times. When might there be alternatives? In this discussion we will look at what liquid trim means and when different trims may be suitable for different relief possibilities.