In horizontal installations a main header is typically bolted into a longitudinal vessel. The header is supplied with welded couplings to accept either screen laterals or pipe based screen laterals. Vertical vessels mounted upright the pattern required of the under drain assembly is round. This style is achieved with a central hub. Again couplings are typically welded to the hub to accept either wedge wire screen laterals or pipe based laterals.
Screen Lateral As an efficient collector, the screen lateral is available in several sizes, with ious slots and end fittings. Most commonly, the screen lateral is provided with a solid cap on one end and a threaded pipe connection on the other end. Pipe Based Lateral Screen laterals are supplied with an internal or external distributor pipe when extra strength and/ or more effective back washing distribution are required.