3-A Sanitary and Hygienic seals for aseptic pipe couplings used in food, dairy, beverage, pharmaceutical process lines, and chemical processing plants. Standard materials available include NBR Buna-N, EPDM, FKM and Silicone. Most decisions driving seal type selection are based on chemistry, temperature, exposure limits, USP, FDA qualifications, and curing methods. ASME-BPE Standard sizing. Industry names include Tri Clamp seals and Tri Clover seals. For premium FFKM and FKM materials, Darcoid recommends HyClamp Sanitary Gaskets from Precision Polymer Engineering.