100% helium leak tested to 1 x 10-4 ml/s for guaranteed performance and reliability
Blow-out proof stem provides a secondary stem seal in the full open position
FKM o-ring seal and PTFE back-up ring below the stem threads to protect from corrosion and galling; PTFE or Graphite packing optional  (certain NPT sizes only)
All stems are 316 Stainless Steel