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Thermoplastic Valves Product Guide & Engineering Specifications
Materials
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®
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Individual Materials Overview
Thermoplastics
PVC — Poly Vinyl Chloride
PVC is one of the most specified thermoplastics for piping
system components, including, valves, fittings, flanges, and
many specialty products. PVC has excellent chemical and
corrosion resistance to a broad range of fluids including
water, deionized water, most mineral acids, bases, salts and
paraffinic hydrocarbon solutions. PVC is not recommended
for use with chlorinated or aromatic hydrocarbons, esters,
or polar solvents such as ketones. Spears
®
PVC materials
conform to ASTM Cell Classification 12454 (formerly des-
ignated as Type I, Grade 1). The maximum recommended
service temperature of PVC products is 140°F (60°C).
Glass Reinforced PVC — Fiberloc
®
Fiberloc
®
is a registered trademark of PolyOne Corporation
Fiberloc
®
is a glass fiber reinforced PVC composite mate-
rial. While maintaining the traditional properties of PVC,
Fiberloc
®
increases its strength, stiffness, and dimensional
stability from glass fiber reinforcement. The maximum
recommended service temperature of Fiberloc
®
products is
140°F (60°C).
CPVC — Chlorinated Poly Vinyl Chloride
Chlorinated PVC is used for higher temperature applica-
tions than PVC, especially for handling hot corrosive
liquids. With similar chemical and corrosion resistance
to PVC, increased chlorine content gives CPVC superior
thermal resistance. CPVC is not recommended for use with
chlorinated or aromatic hydrocarbons, esters, or polar sol-
vents such as ketones. Spears
®
CPVC materials conform
to ASTM Cell Classification 23447 (formerly designated
as Type IV, Grade 1). The maximum recommended service
temperature of CPVC products is 200°F (93°C).
Glass Reinforced CPVC
This special composite compound has the basic properties
of CPVC with additional strength, stiffness, and dimensional
stability from glass fiber reinforcement. The maximum rec-
ommended service temperature of glass reinforced CPVC
products is 200°F (93°C).
PP — Polypropylene
Polypropylene is used in a variety of Spears
®
valves where
different chemical resistance and lower temperature impact
resistance is required as compared to PVC or CPVC. The
excellent impact resistance characteristics of polypropylene
make this polymer the choice for Spears
®
valve handles.
Spears
®
PP products carry a maximum recommended
service temperature of 180°F (82°C).
Glass Reinforced PP
Glass reinforced polypropylene is used in numerous valves
and valve accessories where additional strength or stiffness
is required over standard PP materials while maintaining
basically the same range of chemical resistance.
PTFE/PFA — Polytetrafluoroethylene/
Perfluoroalkoxy Resin
PTFE is a ram extrusion process while PFA is a melt pro-
cessed fluoroplastic. These fluoroplastics are virtually inert
to most chemicals, acids bases and solvents. Due to their
low coefficient of friction, these materials are considered
“self-lubricating” making them an excellent choice for valve
seats, bearings and thrust washers. Spears
®
proprietary pro-
cessing of PTFE with other materials allows low friction
characteristics to be built into a variety of thermoplastic
components used in Spears
®
valves. Fluoroplastics are
serviceable to 500°F (260°C).
PTFE/HDPE
Spears
®
proprietary composition of PTFE and High Density
Polyethylene is used in a variety of valve seats, bearing
washers, and other valve components requiring durability
and improved lubricity. The chemical resistance of HDPE is
somewhat higher than that of LDPE and generally exceeds
that of PVC and CPVC. HDPE has excellent resistance to
acids, alcohols and bases. In comparison to PVC and CPVC,
HDPE is somewhat less resistant to aliphatic hydrocarbons
and has more limited resistance to oxidizing agents. HDPE
is serviceable to 230°F (110°C).
Low Extractable PVC
Low Extractable PVC material developed for use in UPW
(Ultra Pure Water) and other high purity applications.
Independently tested, Low Extractable PVC provides supe-
rior resistance to regular PVC for leaching of anion, cation,
and numerous trace metals when subjected to 18.2 megohm
deionized water while maintaining ease of installation. Low
Extractable PVC has the same basic chemical resistance as
regular PVC.
Elastomers
EPR (EPDM) — Ethylene propylene rubber
Used in O-ring seals, EPR is recommended for water, chlo-
rinated water, dilute acids and alkalines, alcohols, and has
excellent resistance to ozone. EPR is not recommended for
petroleum oils, di-ester lubricants, strong acids, or strong
alkalines. The maximum recommended service temperature
of EPR is 300°F (149°C).