1pcs 25ml to 1000ml Constant Pressure Separating Funnel with PTFE Piston,Drop Funnel for laboratory Extraction experiments5. Application: It is widely used in kinds of labs, experiments, teaching classes and research centre etc.Product Introduction:The constant pressure separator funnel can ensure the constant internal pressure. The first is to prevent backsuction, the second is to make the liquid flow smoothly in the funnel, and the third is to reduce the influence of the increased liquid on the gas pressure, so as to make the measurement of the gas volume more accurate.