How to protect the gear pump against over pressure?
Each gear pump has a stated, maximum operating pressure. If this pressure is exceeded serious damage can occur. A typical scenario is high discharge pressure due to a ‘cold start’, meaning that down stream adapters, screen changers or die heads are still too cold, or that solid (unmelted) material blocks the way.
To protect the pump from over-pressure either rupture discs and/or pressure transducers should be located directly before and after the melt pump. The pressure transducers are typically connected to a control system with dual alarm function (warning and shut down).
eprotec integrates two pressure sensor threads in the housing of the melt-pump as standard. Therefore no additional holes and threads in the adapters prior or after the extrusion pump are necessary.