a bowl guard for mounting , containing and protecting a plastic or glass bowl of a compressed air system device . the bowl guard holds , protects and retains an opaque , transparent or translucent bowl such as a bowl which encloses a filter or lubricator device . the bowl guard is secured to a header of the device and locks the bowl in a sealed relationship with the header . the guard may have apertures so that the contents of the bowl may be observed . a drain through the bowl and guard can be provided when appropriate . a locking pin on the bowl guard insures that the entire assembly is held in alignment . when the bowl guard is latched into place and the system is under pressure the guard may not easily be withdrawn .