PVC is the most frequently used thermoplastic for industrial systems. It is economical, weather and corrosion resistant, non-toxic and offers an exceptionally wide range of selection for fittings, piping, valves and system components. Depending on which chemical will be used (refer to chemical resistance table), PVC has a maximum working temperature of 140°F. PVC installations can use either threaded connections or solvent welded joints. Due to its high corrosion resistance, PVC is commonly used in applications involving acids, salts, water, alkalis, oil and many other chemicals.
It's light weight, high strength and increased temperature resistance combine to make polypropylene the most attractive thermoplastic of the polyolefin. In general, its maximum working temperature is 180°F (please refer to corrosion resistance table for more details). Polypropylene is chemically resistant to organic solvents, as well as most acids and alkalis but should not be used with oxidizing acids, chlorinated hydrocarbons and aromatics. It is ideally suited for chemical wastes, agricultural chemicals, hospitals and laboratories, salt water disposal, crude oil piping systems and low pressure gas gathering systems.
PVDF is a high crystalline thermoplastic material with excellent chemical, physical and mechanical properties. It has excellent chemical and corrosion resistance, is strong, tough and abrasive resistant, and retains most of its strength to 280°F. It is chemically resistant to most inorganic acids and bases, aliphatic and aromatic hydrocarbons, organic acids, alcohol, wet or dry chlorine, bromine and other halogens. Applications include ultra-pure installations in the semiconductor industry, food processing industries, paper, textile and chemical industry, and nuclear waste processing.
PTFE is a straight-chain polymer of TetraFluoroEthylene. It has a high crystalline melting point (620°F), very high melt viscosity, and a high maximum use temperature (greater than 500°F). In addition, it exhibits unusual toughness down to very low temperatures (< -328°F). It is insoluble in all known solvents and resists attack by most chemicals. Dielectric loss is low, whereas dielectric strength is high; anti-stick and antifriction properties are most unusual, inert and antiadhesive are the other important characters. PTFE is a thermoplastic material with a high chemical resistance rating, as well as nonflammable, radiation resistant and thermally stable. Applications include ultra-pure installations in semiconductor industries, biomedical, pharmaceutical industry, as well as chemical, food, and nuclear waste processing.
Copolymers of TFE with perfluoro (propyl vinyl ether) are called perfluoroalkoxy (PFA). PFA shares the same characteristics with PTFE except that its melting point is 68 degrees below that of PTFE. Because its melt-flow rates and critical shear rates are higher than other copolymers, it allows PFA to be an injection moldable material. PFA has all the other advantages of PTFE such as: high working temperature, anti-stick performance, resistance to virtually all chemicals, low coefficient of friction, non-flammability, and excellent electrical properties. This is a great material suitable for all applications that require a smooth wetted surface to prevent contamination and bacterial growth.
EPDM is a terpolymer elastomer made from ethylene-propylene diene monomer. It offers excellent resistance to polar fluids such as water, phosphate esthers and ketones but is not recommended for petroleum oils and solvents. EPDM possesses excellent resistance to heat degradation, compression set, low temperatures, sunlight, ozone, weathering, abrasion and tear resistance. The effective temperature range is -70°F to +300°F.
A fluorocarbon elastomer having excellent mechanical and physical properties. Outstanding resistance to oils, lubricants, mineral acids, salt solutions, blended aromatic fuels and straight aromatics as well as halogenated hydrocarbons. The effective temperature range is -20°F to +500°F with limited service to +600°F.
Chemraz and Kalrez are members of the perfluoroelastomer family. Polymer chemists describe the base (raw) perfluoroelastomers as polymers of three or more monomers in which all hydrogen positions have been replaced with fluorine. The outstanding resistance of perfluoroelastomer vulcanizates to heat and most chemicals and solvents is the result of this state of complete fluorination. The principal monomer of both Chemraz and Kalrez is tetrafluoroethylene (TFE). The effective temperature range for Kalrez is +5°F to +600°F, for Chemraz -20°F to +450°F. A white Chemraz compound is available and features less impurities and less electrical conductivity.