Sealing technology manual for the process industry - Storage tests

STORAGE TESTS Freudenberg has carried out extensive exposure testing. The database for the CIP/SIP cleaning agents consists of over 200 compositions and 5,100 measurements. The tests were conducted using the highest recommended operational concentrations and temperatures. EPDM EPDMishighlyresistanttoacids,alkalinesolutions,oxidizingme- dia, cleaning agents and sterilization (including steam). But at higher temperatures and concentrations, EPDM swells in media containing fat and cannot therefore be used everywhere. The operationaltemperaturesrangebetween–40°Cto+150°C(–40 °F to +302 °F) in air and up to +180 °C (+356 °F) in steam (briefly upto+210°C(+410°F)). HNBR If a seal is intended to be mainly resistant to non-polar media, HNBR can be taken into consideration. Seals made of HNBR can coverabroaderrangeofapplications;however,theirdurabilityin aggressive CIP/SIP cleaning agents is lower than EPDM. HNBR shouldnotbeusedinconcentratedacids.Operationaltempera- turesinairandinwaterreachupto+150°C(+302°F). VMQ If the seal does not necessarily have to be sterilized with hot steam, silicone (VMQ) can also be used apart from HNBR. VMQ isresistanttonon-polarandpolarmedia,butinsteamitcanonly beusedintemperaturesupto+120°C(+248°F).Itstemperature rangeinairisfrom–50°Cto+200°C(–58°F to+392°F). FKM If a seal is required that can be used in non-polar media such as fatandoilupto+180°C(+356°F)andthatisalsoresistanttoCIP/ SIP media and steam, FKM should be used. FKM is also well- suitedforusewithcitrusjuicesandaromaticoils.Itstemperature rangeinairisfrom–15°Cto+200°C(+5°Fto+392°F).Ifalkaline cleanersareinoperation,FKMisnottheoptimalsolution.Inthis caseFluoroprene®XPisthebettermaterial. Fluoroprene®XP SealsmadeofFluoroprene®XPcanalsobeusedifEPDMisinfea- siblebecausethefatconcentrationistoohigh.Thismaterialnot only shows excellent resistance to acid, alkaline solutions and steam,butalsotofatsandmostflavoringagents.Itcanbeused attemperaturesof–10°Cto+200°C(+14°Fto+392°F). Simriz® Iftherequirementsaresohighthatnoneofthepreviouslymen- tionedsealingmaterialsissuitable,sealsmadeofFFKMareused. Simriz®offerscomprehensivemediaresistanceinatemperature rangeofupto+260°C(+500°F). FKM Fluoroprene® XP Simriz® Resistance of FKM, Fluoroprene® XP and Simriz® 100 90 80 70 60 50 40 30 20 10 0 Nitric acid (2 %, +80 °C (176 °F)) Sodium hydroxide (5%, +80 °C (+176 °F)) Active oxygen (<1%, +35 °C (+95 °F)) Active chlorine (3%, +60 °C (+140 °F)) Fat (>40 %, RT) Steam (+140 °C (+284 °F)) Resistance of EPDM, HNBR and VMQ EPDM HNBR VMQ 100 90 80 70 60 50 40 30 20 10 0 Nitric acid (2 %, +80 °C (176 °F)) Phosphoric acid (4%, +70 °C (+158 °F)) Sodium hydroxide (5%, +80 °C (+176 °F)) Active oxygen (<1%, +35 °C (+95 °F)) Active chlorine (2 %, +80 °C (+176 °F)) Fat (>40 %, RT) Steam (+140 °C (+284 °F)) Materials resistance and purity Phosphoric acid (4%, +70 °C (+158 °F)) 64

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