Let me sugget to classify the type of trays according to the type of downcomer, not type of valves.
1. Conventional Trays (1pass & 2pass & 4pass with straight downcomer and slopped downcomer)
2. High Capacity trays are classified with High Performance Tray and High Capacity Tray.
2.1 High Performance tray has some special shape of downcomer for enhanced bubbling area.
2.2. High Capacity tray has multi-downcomers like UOP MD tray and Shell HiFi Tray.
Some clients and licensors are confused. For example, the type of tray is specified on the data sheet as conventional tray. A licensor who dosen’t have many experience of that process, they want to keep the original type of tray installed at existing plant. That column has lower pressure drop, the fixed valve should be installed as a conventional tray. But licensor doesn’t accept that fixed valve as conventional tray, because that fixed valve is introduced as high performance valve at the brochure. So, licensor thought fixed valve tray is not conventional tray, but high performance tray. I explained several times about that concept of tray, finally he accpeted it as a conventional tray. From that time, i think the type of tray needs to be described by the FRI which has public confidence.