= Nitrile Butadiene Rubber
(synthetic rubber; also known as Perbunan^® or Buna-N^®)

• Used in O-rings and diaphragms
• Good resistance to fuels and oils
• Not resistant to solvents

= Ethylene Propylene Diene Monomer
(EPDM) Synthetic Rubber

• Used in O-rings and membranes
• Good resistance to alkalis
• Not resistant to fuels, oils, or solvents

= Fluoroelastomer ("fluororubber," methylene type)
(synonyms: FPM, Viton^®, or Tecnoflon^®)

• Used in O-rings and diaphragms
• Good resistance to alkalis
• Widely used sealing material

= Perfluoroelastomer Type M
(also known as Kalrez^® or Simraz^®)
Fully fluorinated elastomer

• Used in O-rings
• Very good resistance to acids and alkalis (similar to PTFE)
• Very expensive (10–14 times more expensive than FKM)

= Fluorinated ethylene propylene
fluorocarbon

• Use in O-rings
• Very good resistance to acids and alkalis (similar to PTFE)
• Not very flexible

= Chloroprene rubber Type R
(also known as Neoprene^® or Chloroprene^®)

• Used in membranes
• Good resistance to oils
• Very flexible

= Polypropylene-EPDM copolymer
(also known as Santoprene^®)

• Used in membranes
• Combines the properties of PP and EPDM
• Good resistance to alkalis
• Do not use with oils

= Polypropylene
(synonym: Hostalen^®)

• Used in pumps, housings, and fuel nozzles
• Good resistance to aggressive media, acids, alkalis, and neutral, non-flammable liquids
• Available as semi-finished products in the form of pipes and sheet material
• Available as granules for injection molding
• Weldable
• Color: Gray for pumps
• Operating temperature range up to approx. 50°–60° C

= Polyvinylidene fluoride

• Used in pumps and housings
• Excellent resistance to strong acids and alkalis, as well as neutral, non-flammable liquids
• Available as semi-finished products in the form of tubes and sheet material
• Available as granules for injection molding
• Weldable
• Color: White, as with the pumps
• Operating temperature range up to approx. 80° C
• Twice as expensive as PP

= Polyphenylene sulfide
(also known as Ryton^®)

• Used in the measuring chamber of the FMC 100 flowmeter
• Used in the housings and oval wheels of the FMO flowmeter
• Good resistance to acids and alkalis
• High dimensional stability
• High mechanical strength
• Available as granules for injection molding

= Polytetrafluoroethylene
(also known as Teflon^®)

• Used in membranes, stators, and plain bearings
• Excellent resistance to all liquids
• Available as semi-finished products in tubes or sheet form
• Easy to machine
• Cannot be welded

= Polytetrafluoroethylene + 33% carbon
(synonym: Teflon^®)

• Used in plain bearings and mechanical seals
• Excellent resistance to all liquids
• Electrically conductive

= Ethylene
tetrafluoroethylene (synonym: Tefzel^®)

• Used in the rotors and measuring chambers of the FMC flowmeter
• Excellent resistance to all liquids
• High dimensional stability
• High mechanical strength
• Available as granules for injection molding

= Polyoxymethylene
(also known as Acetal^® or Delrin^®)

• Used in housings for compressed-air diaphragm pumps
• High dimensional stability
• High mechanical stability
• Easy to machine
• Do not use with strong acids or oils
• Electrically conductive

= Polyamide
(also known as Nylon^® or Rilsan^®)

• Used in FEM 4070 motor housings
• High dimensional stability
• High mechanical stability
• High temperature stability

= Polyethylene
(also known as Hostalen^® or Lupolen^®)

• Used in the measuring chamber of the FMC 250 flowmeter
• Good resistance to acids and alkalis
• Easy to process
• Available as granules for injection molding

= Stainless steel (1.4571)

• Used in shafts, pumps, fuel nozzles, and housings
• Used with highly flammable media, acids and alkalis, solvents, and in pharmaceutical and food applications
• Weldable
• Electrically conductive
• Very commonly used in the chemical industry

= Hastelloy C (2.4610)

• Highly corrosion-resistant nickel-molybdenum alloy
• Used in shafts and pumps
• Used with strong acids and alkalis as well as highly aggressive media
• Weldable
• Electrically conductive
• Very expensive (3.5 times more expensive than stainless steel for barrel pumps)

= Aluminum (AlMg₅)

• Used in pumps and fuel nozzles
• Used primarily for oils (diesel, hydraulic oil), but also for neutral, non-flammable media
• Weldable

Must no longer be used for highly flammable media, as an electrically non-conductive oxide layer may form on the surface of the pump!

= Gray cast iron

• Used in the housings of compressed air diaphragm pumps
• High surface hardness
• Specifically used for abrasive media

= Titanium

• Used in the shafts of barrel pumps
• Good resistance to highly corrosive media
• Used with hydrofluoric acid (HF) and ferric chloride (FeCl_₃) or when HC offers only limited resistance