What is “high temperature” in hydraulic-sealing applications? Most hydraulic seals are NBR rated at 250ºF. So is anything over 250ºF high temperature?
Many engineers specify FKM for applications over 250ºF – a safe bet for temperatures exceeding 325ºF, but what about applications between 250ºF and 325ºF? Do you really need the added protection of FKM at about eight times the cost of NBR?
Consider HNBR for 250ºF to 325ºF at about half the cost of FKM.
by Bruce MacIntyre, AY Seal and Packing Co. (bruce@alleghenyyork.com)