PTFE filter elements are produced by sintering pure PTFE granules, no other substances are used in the construction. These filter elements are usually offered when only 100% pure PTFE can be used. It is normally preferable to offer a K type disposable filter element, if suitable, as both pressure drop and life characteristics are superior to the PTFE elements. The advantage of PTFE is a higher maximum temperature, up to 200°C, and somewhat better chemical resistance. These filter elements should be ultrasonically cleaned to give best results.