Check valve with intermediate air release port. It can be easily installed to prevent a back flow of lubricant when redirecting the air flow. This check valve is typically used between a regulator and a lubricator to supply an unlubricated air supply. The check valve keeps lubricated air from getting into the unlubricated lines.
THESE CHECK VALVES ARE NOT THREADED.
THEY ARE FOR USE WITH FRL UNITS ONLY.