First of all, there are many kinds of filters, such as oil filter, water filter and air filter. Secondly, there are many domestic manufacturers of filters, such as Xinxiang, Hebei and Jiangsu. Generally, there are many mechanical filters for engine oil produced in Xinxiang and many water filters produced in Jiangsu, depending on the filter you need. You can search for demand information online, and now there is more information about manufacturers online. Secondly, the filter is an indispensable equipment in the medium conveying pipeline, which is usually installed at the inlet end of pressure reducing valve, pressure relief valve, constant water level valve and other equipment.