Via pressure blowing or vacuum suction, pneumatic conveying systems can be divided as pressure system and vacuum system.
Vacuum system is more common for lower conveying capacity and shorter conveying distance as the pressure drop has a limitation normally up to 0.5bar, and almost no way to go to 1 bar.
Vacuum systems normally employ simple and cheaper pick up nozzles / wands instead of expensive rotary valve. However a rotary valve may be need in case of poor flowing product or higher conveying capacity.
Compass provides modular vaccum receivers via vacuum pump (series Loader P) or venturi vacuum generator (series Load V, client to provide compressed air) and vacuum sequencing system, either in dilute phase conveying technology or dense phase conveying technology denpending on the actual industrial application.