THERMOPLASTICS AND ELASTOMERS

Chemical Resistance Guide (reference only)

ABS
ACRYLONITRILE - BUTADIENE - STYRENE - Class 4-2-2 conforming to ASTM D-1788. Temperature range from -40 degrees F to 180 degrees F. Excellent resistance to deposit formation. Superior resistance to sewage and common chemical formulations. Good impact resistance (many automotive parts, bumpers and panels). ABS can be joined by cementing, threading and flanging.

PVC
POLYVINYL CHLORIDE - Class 12454-B Type 1, Grade 1 to ASTM 1784. Temperature range from -30 degrees F to 140 degrees F. PVC is the most common and most widely used thermoplastic material. It resists most acids, strong Alkalis, salts and paraffinic hydrocarbon solutions. Excellent for industrial chemical and plating systems, deionized water, irrigation and drainage systems. PVC is not recommended for use with chlorinated or aromatic hydrocarbons, esters or polar solvents such as ketones. The material can be joined by cementing, threading or flanging.

CPVC
CHLORINATED POLYVINYL CHLORIDE - Class 23447-B Type IV Grade 1 to ASTM D-1784. The physical properties at 73 degrees F are very similar to PVC. CPVC has a slightly better chemical resistance and has a higher temperature range to 210 degrees F. It is not recommended for use with chlorinated or aromatic hydrocarbons, esters or polar solvents such as ketones. The material can be joined by cementing, threading or flanging.

PP
POLYPROPYLENE - Type 1 to ASTM D-4101 class PP10-B67154. Temperature range from - 30 degrees F to maximum 180 degrees F but at this temperature we recommend it's use only with water or drainage. PP is the lightest of all plastics. Resistant to organic solvents, acids and alkalis. It is not recommended for oxidizing acids, chlorinated hydrocarbons or aromatics. Mostly used for sulfur-bearing materials, saltwater solutions, crude oil and low pressure gas systems. PP can be joined by thermo-seal fusion, threading or flanging.

PVDF (Polyvinylidene Fluoride)
POLYVINYLIDENE FLUORIDE - ASTM D-3222 having a temperature range of -80 degrees F to 280 degrees F. The strongest, heaviest and most abrasion resistant of the thermoplastic materials. PVDF is resistant to most acids, bases and organic solvents and is the only thermoplastic resistant to wet or dry chlorine, bromine and other halogens. PVDF can be joined by thermo-seal fusion, threading or flanging.

PTFE (Polytetrafluoroethylene)

PTFE is practically insoluble and chemically inert to most chemicals and solvents. It is widely used in the handling of high purity deionized water. While PTFE is capable of 500°F (260°C) Plast-O-Matic does not recommend its use in valve designs beyond 300°F (149°C).

The main advantages of PTFE in valve design is that it is ideal for both high purity and highly corrosive applications, because it is virtually impervious to corrosion, and is extremely low in terms of leaching. It is also excellent for valve parts due to its low frictional properties. Its limitations are that it will "cold flow," i.e., PTFE can be reshaped after contact with other parts. It is also not ideal for higher pressure threaded connections on larger pipe sizes.

PTFE is joined by threading or flanging.

TEFLON®
POLYTETRAFLUOROETHYLENE - A self lubricating compound.Resistant to almost all chemicals and solvents and has a very high thermal-stability, also nonflammable. Temperature range of -20 degrees F to 400 degrees F.

PFA (Perfluoroalkoxy resin)

PFA is a melt processible fluoroplastic equal to PTFE in chemical resistance. It is used for many valve parts such as bellows in solenoid valve, and encapsulation of springs when used as a wetted part. PFA is also used for molded body valves, and although the PTFE valve has a different appearance and translucence, the PTFE valve can be used in place of a PFA valve with no change in chemical resistance. Both materials are equally inert and have the same dielectric constant.

FEP (Flourinated ethylene propylene)

FEP is a relatively soft fluoroplastic, with the same inert, low dielectric, and low friction properties of PTFE and PFA. It does not offer quite the same mechanical properties at elevated temperatures as PTFE and PFA.

PYREX® (borosilicate glass)

This low alkali glass is used on sight glasses and level indicators. It resists attack from most bases and acids with the exception of hydrofluoric acid and sodium hydroxide. It is the same material used in glass piping systems in the food, beverage, chemical, and pharmaceutical industries.

Elastomers:

EPDM (Ethylene Propylene Diene Monomer)
A terpolymer elastomer made from ethylene-propylene diene monomer. Recommended for water, chlorinated water, dilute acids, alkalines, alcohols and ozone. Not recommended for petroleum oils, strong acids and alkalines. EPDM has a temperature range from -20 degrees F to 230 degrees F.

VITON® (Vinylidene Fluoride - Hexafluoropropylene)
FLUOROCARBON ELASTOMER - Recommended for hydrocarbon service, mineral acids, salt solutions, chlorinated hydrocarbons and petroleum oils. Viton has the broadest temperature range of the elastomers from -20 degrees F to 300 degrees F but should not be used in steam service.

NITRILE
(BUNA-N) - A copolymer of butadiene and acrylonitrile. Has good resistance to solvents, petroleum oils and fluids, di-ester lubricants, ethylene glycol based fluids, aliphatic hydrocarbons and aromatic solvents. It should not be used with acetone and methyl ethyl ketone, chlorinated hydrocarbons, ozone or nitro hydrocarbons. Temperature range from -20 degrees F to 180 degrees F.

HYPALON ®
A chlorosulfonated polyethylene elastomer has good resistance against nitric, hydrofluoric and sulfuric acids, aliphatic hydrocarbons and aromatic solvents. It is not recommended for exposure to concentrations oxidizing acids, esters, ketones, chlorinated, aromatic and nitro hydrocarbons. Temperature range from -20 degrees to 200 degrees F.

NEOPRENE
A chlorinated synthetic rubber elastomer. It is flame resistant and resists animal and vegetable oils. Recommended for food and beverage service. Normally not effected by moderate chemicals, fats, greases and many oils and solvents. Neoprene is not recommended for strong oxidizing acids, esters, ketones, hydraulic fluids, chlorinated solvents and aromatic hydrocarbons. Temperature range from -20 degrees F to 160 degrees F.

Fluorosilicone Rubber

This elastomer is noted for its retention of flexibility, resilience and tensile strength over a wide temperature range. It is not, however, noted for its chemical resistance.

Kalrez® & Chemraz® (Perfluoroelastomer)

(Kalrez is a perfluoroelastomer manufactured by DuPont Dow Elastomers; Chemraz is a perfluoroelastomer manufactured by Greene Tweed.) These elastomers combine the chemical resistance of Viton and fluoropolymers, making it far superior to most other elastomers. However, because of its high cost it is only used where absolutely required. It is only available in O-ring and sheet form so it cannot be used with all valve designs.

Aflas® TFE (Tetrafluoroethylene/propylene dipolymer)

Aflas is a brand name manufactured by 3M. Aflas is an alternative to perfluoroelastomers in many applications. It offers excellent chemical and electrical resistance, and service temperatures to 400 degrees F (204 C) It is especially resistant to newer specification automotive lubricants, battery acids, jet and rocket fuels, oilfield applications, and more. The most common use in plastic valves is in ozone water treatment systems, where it is excellent.