Lever & Gear-Operated 2"-12"
Lug type valves, as the name suggests, have lugs that are used to mount the valves. These are then attached to the flanges on then ends of sections of pipe so that each length of pipe can be removed and replaced independently.
Wafer type valves don’t have attachment lugs, they have through bolt holes. They are sandwiched between the flanges on the ends of two lengths of pipe. To replace either length of pipe requires shutting the system down.