This filter dryer is filled with desiccant and is designed to filter and dry the air.  This unit screws inline with 1/4” NPT fittings commonly used for compressed air.  When new, the desiccant should be colored, usually pink or blue.  The filter dryer is used up when the desiccant changes to mostly clear.  The filter dryer must be replaced to continue protection of the compressed air system and torch when the desiccant is clear.  The life of this filter depends on other filters in the system (if any), and the humidity of the air entering this filter dryer.  The life of this filter dryer can be extended with an additional water separating filter before this filter is inline.  This is an economical way to begin with compressed air in a torch.  It is a good idea to have an extra filter dryer on hand before this unit is used up.  For a permanent, long lasting solution please see ourfilter dryer with coalescing filter.