... as handkes, gear box, electric actuator and pneumatic actuatorsb) Stem Round with key, square and double "D" for your ... selection.c) O ring prevent stem from leakaged) Shaft seal : bounding of elastomer to phenolic ... Alloy AluminumDisc: Plated Ductile Iron, Aluminum Bronze, Stainless Steel, Carbon SteelStem: Carbon Steel, Stainless SteelSeat: NBR, EPDM, Heat Resistant EPDM, VITON ...