1. Introduction to Y-type Filter

2. Testing principle of Y-type filter

Diffusion flow testing principle: Diffusion flow testing refers to when the gas pressure is 80% of the bubble point value of the filter element, a large amount of gas perforation has not yet occurred, but a small amount of gas first dissolves into the liquid phase diaphragm, and then diffuses from that liquid phase to the gas phase on the other side. This part of gas is called diffusion flow.

Why is the method of diffusion flow better? The bubbling point value is only a qualitative value, and the process from the beginning of bubbling to the final group bubbling is a relatively long one, which cannot be accurately quantified. The measurement of diffusion flow value is a quantitative value that not only accurately determines the integrity of the filter, but also reflects issues such as membrane porosity, flow rate, and effective filtration area. This is why foreign manufacturers now use diffusion flow method to test integrity.

Water intrusion method testing principle: Water intrusion method is specifically used for testing hydrophobic filter elements. The hydrophobic membrane resists water, and the smaller the pore size, the greater the pressure required to squeeze water into the hydrophobic membrane. So, under a certain pressure, measure the water flow rate squeezed into the filter membrane to determine the pore size of the filter element.