Braided Packing styles for Valve Stems are generally developed to seal against higher pressures found in valve stuffing boxes. The most popular styles of packing used today are manufactured of graphite or carbon yarns, and some can withstand both high pressures and provide a fire safe seal with EPA Emissions Compliance. Packing made of PTFE yarns are also used where the use of graphite or carbons are not desirable. PTFE however, is not a “Fire Safe” product.
The Valve Stem may simply rotate as in a ¼ ball valve or the stem may turn and rise as in a gate style valve. Since valves are now designed to allow zero leakage, it is very important to inspect the valve stem for nicks or scratches prior to packing installation.