... of construction:Body: Cast Iron, Ductile Iron, Carbon Steel, Alloy AluminumDisc: Plated Ductile Iron, Aluminum Bronze ... , Stainless Steel, Carbon SteelStem: Carbon Steel, Stainless SteelSeat: NBR, EPDM, Heat Resistant ... EPDM, VITON,Pin: Stainless SteelBushing: PTFE, BronzeRing: NBR, EPDM, ...