Mechanical Seal for Nitric Acid Mechanical Seal for Nitric Acid kamaqal (Chemical) (OP) 3 Nov 16 19:26 Hello Dear members I want your guidance in selecting mechanical seal. Which mechanical seal is best for handling Nitric Acid? Viton or EPR. if there is any reference available. Thank you RE: Mechanical Seal for Nitric Acid johncaboth (Mechanical) 11 Nov 16 08:50 Ring M1 Burgmann RE: Mechanical Seal for Nitric Acid Chpal1984 (Mechanical) 11 Nov 16 11:33 This is always a good source for these queries https://www.parker.com/literature/ORD%205700%20Par... In this case it depends on the concentration of Nitric acid. If its between 0-50%, then you can use viton. Otherwise your looking at perfluoroelastomers I'm afraid.