Vacuum Pumps, in Central Plastics Conveying Systems generate vacuum in the air lines, which, in turn, pulls plastics materials through the material lines to Vacuum Receivers (Vacuum Stations). There are several types of Vacuum Pumps. The most common is a Positive Displacement Pump (PD Pump). Others may be called CLAW Pumps or Hook and Claw pumps or just Long Distance Pumps (because of the high vacuum levels they generate). Yet others have a spiral flow design. They are a special type of PD Pump – referred to as MaxFlow. Finally, there are Regenerative Blowers (Regen Pumps) where a blower actually creates the vacuum. When designing a Central Plastics Conveying System, the plant layout is the first thing that has to be considered but the Vacuum Pumps are the starting point in a Plastics Conveying System design. The choice of pump type and Hp depends on the type of material being conveyed, the distance it is being conveyed and the pounds/hour required at each destination. It’s important that processors not be corralled into using a single type of pump for every application.