The left picture shows cell dividers of a traveling bridge filter. EIMCO, now OVIVO, used to sell several decades ago a nozzle-based traveling bridge filter mainly for wastewater tertiary treatment. Not really sure why they would think this picture is relevant today.
The middle picture shows a precast block style of nozzle-based underdrains. These blocks are arranged side-by-side, grouted in-between, and cinched down with hold-down hardware to create a suspended floor underdrain. This technology is mainly used in second and third-world countries where enough consistent-quality concrete mix cannot be found to pour a monolithic floor. The grout in-between the pre-cast blocks, much like the grout in-between plastic block underdrain laterals, is a point of repeated failure. It also appears in this picture that a one-inch skim coat was poured, which wasn’t a good idea. This picture is not a monolithic underdrain system such as the resilient Orthos Centurion™, so we’re not sure why they included this picture either.
The bottom picture admittedly took us a little while to figure out. After contacting a well-experienced colleague in Europe, he pointed out that this is a pipe lateral system with a failure of the central channel—he’s seen some of these over there. It appears that the riser tubes, not nozzles, are embedded in concrete above the laterals. This is really a poor design and it’s no wonder that it blew up. With no nozzles and being a pipe lateral system, we seriously question why “Brand X” would believe this picture is relevant.