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Types
of Butterfly Valves
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| 1 |
Plastic
Butterfly Valves |
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| Plastic
butterfly valves are available in two types or styles, wafer or lug. A
different installation procedure is used for each one. |
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| 2 |
Wafer
Style Valves |
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| Wafer
style is the more common of the two and is less expensive than the lug
style. The wafer style butterfly valves is just about the "standard".
It's so common that no one even bother to use the word wafer when ordering
a butterfly valve. They take it for granted that if they order a "butterfly
valve" they will get a wafer style one. |
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| 3 |
Wafer
Butterfly Valves |
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| Wafer
butterfly valves are installed between two flanges using bolts or studs
and nuts. This type of installation, of course, makes it impossible to
disconnect just one side of the piping system from the valve. That' where
the lug style valve comes in. |
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| 4 |
Lug
Style Valves |
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| Lug
style valves have metal inserts installed in the valve's bolt holes. These
inserts are threaded on both ends. This allow them to be installed into
a system using two sets of bolts and NO nuts. The valve is installed between
two flanges using a separate set of bolts for each flange. This set up
permits either side of the piping systems to be disconnected without distributing
the other side. |
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| 5 |
Lug
Style Butterfly Valves |
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| Lug
style butterfly valves used in dead end service generally have a reduced
pressure rating. For example most sizes of Hayward butterfly valves mounted
between two flanges have a 150 psi pressure rating. The same valve mounted
with one flange, in dead end service, has a 75 psi rating. |
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Copyright
HAYWARD Industrial Products, Inc. 1999
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Types
of Butterfly Valves