When multiple vacuum pumps are joined to a common exhaust, the common exhaust must be sized to achieve what?

When multiple vacuum pumps are connected to a common exhaust, sizing the common exhaust primarily aims to minimize back pressure. This is crucial because excessive back pressure can hinder the efficiency of the vacuum pumps. It can cause a reduction in their performance, as pumps are designed to operate under specific pressure conditions. If the exhaust system creates too much resistance, it may limit the ability of the pumps to remove air or gases effectively from the system, leading to operational inefficiencies or potential damage over time.

Minimizing back pressure ensures that exhaust gases can flow freely away from the pumps. This enables the pumps to maintain their intended vacuum levels without the interference of resistance that could arise from an improperly sized exhaust. Consequently, achieving an appropriate design for the common exhaust is essential for properly functioning multiple vacuum pumps in a medical gas installation or any similar application where precise vacuum conditions are necessary.