Sealing technology manual for the process industry - EPDM

The excellent resistance to water and aqueous systems makes EPDM (ethylene-propylene-diene rubber) the most widely used material in food production and processing, with a share of about 70%. General properties • Very good resistance to aging, ozone and light • High heat and cold resistance, approx. –50 °C to +150 °C (–58 °F to +302 °F) • Good tensile elongation and strength • Very high abrasion resistance • Very good resistance to water and to polar and oxidative media • Excellent elastic behavior 70 EPDM 291 (black) and 70 EPDM 253815 (white) Application profile EPDM seals exhibit good chemical resistance in hot wa- ter, steam, acids and alkaline solutions. They are very well suited for use in all polar media and therefore also in CIP/ SIP media. CIP media are diluted acids or alkaline solu- tions with cleaning additives. In SIP media, disinfectants, steam or oxidizing media (e.g. peracetic acid) or polar or- ganic solvents (e.g. acetic acid) are used. EPDM is of lim- ited use in products containing fats or oils. While it can be used well at low temperatures in dairy products with a fat content of up to 70%, it cannot be used in pure fats, oils or non-polar solvents. EPDM contains no plasticizers and other potential extractable ingredients and therefore displays negligible amounts of extract in the extractables study (see page 61 f.). Thus, the materials EPDM 291 and EPDM 253815 can be recommended for use in the manufacture of medical products. Suitable areas of application • Hot water and steam (on a sustained basis up to +180 °C (+356 °F), briefly up to +210 °C (+410 °F)) • Acids (hydrochloric acid, nitric acid and phosphoric acid) • Alkaline solutions (sodium hydroxide solution, potassium hydroxide solution) • Polar organic solvents • CIP/SIP media for continuous operation plants in the food, beverage and pharmaceutical industries EPDM in the dairy industry EPDM cannot be used in every product containing fat, which limits but does not completely rule out its use in the dairy industry. According to DIN 11483, dealing with dairy plants, the use of EPDM is only recommended for products with a fat content of up to 15%. This is no longer true today as such. The chart gives a rough indication of the usability of EPDM in the interaction between fat content and tem- perature of the medium. If the process parameters are be- low the curve, EPDM can and should be used. Only in appli- cations with parameters above the curve should a different elastomer be selected. EPDM is also of only limited use EPDM RULES AND STANDARDS 70 EPDM 291 70 EPDM 253815 FDA-compliant (CFR 21 Part 177.2600) + + EU Reg. 1935/2004 EU Reg. 2023/2006 + + 3-A® Sanitary Standards Class II* + + USP Ch. 87 (in vitro) USP Ch. 88 (in vivo), Class VI – 121 °C (250 °F) + + + + Drinking water: DVGW (W 270 and 534), KTW, WRc-NSF, NSF 61, ÖVGW, ACS, WQC + NSF 51 + *Note: • Class II because of the bad resistance against fat and oil (max. 8 % butterfat at +70 °C (+158 °F)) • Class I in aqueous CIP/SIP media at +82 °C (+180 °F) • Class I in sterilization at +149 °C (+300 °F) Elastomeric materials 34

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