Abstract: A float valve 80, made of HDPE, is movably mounted in a stainless steel cage 60 in an in-line vacuum filter. The float valve has a chamber 85 formed in a skirt portion 84 thereof. Float valve 80 has a generally cylindrical shaped outer surface 82 encircling the skirt portion 84 and a generally cylindrical shaped inner surface 83 encircling the chamber 85. A upper portion 86 extends across the upper end of valve 80 to form an inverted cup shaped body. The upper portion 86 extending across the upper end of said valve 80 has a threaded hole 87 formed therein to receive a threaded bolt 88 for forming a ballast to permit adjustment of the weight of said valve 80 so that it floats at a level that prevents it being drawn by venturi effect into the central air chamber 19 before a predetermined volume of liquid is collected in the cylindrical enclosure 11 through which air flows en route to the filter element 14.