Note: Descriptions are shown in the official language in which they were submitted.
1~80196
This invention relates to a wafer type butterfly
valve~ More particularly, the invention relates to a wafer
type butterfly valve for mounting between two conduit flanges~
Butterfly valves, particularly thin, wafer type
butterfly valves are well known. The valves are normally
mounted between the flanges of aligned, adjacent conduits or
pipes in fluid systems~ In one mounting method, long flange
bolts are employed joining the adjacent flanges of adjacent --
conduits together with the valve sandwiched tightly between
the ~langes. In this method, the bolts do not connect to the
body of the valve. This method has the advantage of allowing
the valve body to be made out of material that can withstand
compression but need not withstand bending or tension. A
valve body sandwiched between flanges is not placed under any
tension or bending forces by the connecting bolts. Thus the
valve body may be made from an inexpensive material such as
cast iron. A disadvantage in using long flange bolts for
joining the two flanges together is that the system cannot ;
be closed by the valve when replacing conduit at the valve
location because the valve is not joined to either flange of
the conduits. Also, the valve must always be handled and re-
positioned when replacing one or both conduits.
Another mounting method for thin wafer type valves -
employs short lug bolts. One set of lug bolts connects a
flange of one conduit directly to the valve body on one side
and another set of lug bolts connects the flange of another
conduit directly to the valve body on its other side. The
valve body can be provided with threaded holes for receiving
lug bolts from both flangesO When using this mounting method,
the conduit on either side of the valve can be replaced without
disturbing the valve and either conduit can be closed by the
valve held to the flange by the lug bolts. One disadvantage
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of fastening the flanges directly to the valve body however
is any tension or bending forces between the conduits are now
transmitted directly through the valve body because of the
direct connection of the flanges to the valve body by the lug
bolts. Therefore, the valve body must be made of a material
such as steel which withstands tension and bending forces
Steel valve bodies are however more expensive than cast iron
valve bodies.
It is a purpose of the present invention to provide
a wafer type butterfly valve that is constructed to be mounted
between flanges of adjacent conduits so the fluid system can
be used under high pressure operating conditions. It is another
purpose to provide a wafer type butterfly valve that can be
mounted between flanges of adjacent conduits and pressure may
be maintained in either conduit while the other conduit is
disconnected from the valve. Thus a conduit may be replaced
without having to shutdown the complete fluid system, It is a
further purpose of the present invention to provide a wafer
type butterfly valve that can be located between flanges of
adjacent conduits and can withstand pressure between either
; conduit and the valve but allows some of the bending stresses
to be passed from flange to flange omitting the valve body.
In accordance with the present invention there is
provided a butterfly valve constructed so it can be mounted
between standard pipe flanges with both flange bolts and lug
bolts. The flange bolts are employed to provide a tight seal
and to carry tension and/or bending forces between the pipe
flanges omitting the valve body thereby permitting the valve -
body to be made from a cheaper material such as cast iron.
The lug bolts are employed to permit either pipe flange to be
changed without disturbing the position or operation of the
valve and with pressure remaining on the other side of the
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valve. Thus, if a pipe flange is to be replaced, the flange
bolts between the two flanges are removed and the lug bolts
joining the flange to the valve are also removedO The valve
is, however, still fastened by lug bolts to the other flange
while a new flange is being replaced.
The present invention provides in a wafer type valve
for locating between two conduit flanges, including a thin valve
body with flat parallel mounting surfaces, a central bore ex-
tending between the mounting surfaces and closing means within
the central bore, the improvement comprising a plurality of
threaded mounting holes extending between the mounting surfaces
and positioned on a circle outside the central bore adapted
for lug bolts connecting the valve body to each of the two
conduit flanges to withstand conduit pressure between the
valve and each flange, and a plurality of gaps in the valve
body, the gaps located on the circle between the holes adapted
for long bolts connecting the two conduit flanges together and
transferring some bending stress directly from flange to flange
omitting the valve body.
In other embodiments the mounting holes are equally
spaced apart around the circle, and the gaps comprise portions
removed from a peripheral edge of the valve body between the
mounting surfaces. The valve body may have a generally square
shape with a mounting hole in each corner, and is preferably
made of cast iron.
The present invention also provides a fluid system
including a wafer type butterfly valve with a conduit on each
side, each conduit having a flange with a plurality of holes
evenly spaced apart around a circle, the conduits being in line
and the holes in the flanges being in line, the valve com-
prising a thin valve body with flat parallel mounting surfaces
for positioning against the flanges, a central bore extending
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between the mounting surfaces, closing means within the central
- bore, a plurality of threaded mounting holes extending between
the mounting surfaces in line with alternate holes in the flanges,
a plurality of gaps in the valve body, the gaps in line with
the remaining holes in the flanges, a plurality of lug bolts
holding each flange to the threaded mounting holes within the
valve body to withstand conduit pressure between the valve body
and each flange, and a plurality of long bolts extending through
the remaining holes in the flanges, connecting the flanges
together and transferring some bending stress directly from
flange to flange omitting the valve body.
In drawings which illustrate embodiments of the
invention,
Figure 1 is an elevational side view of a butterfly
valve mounted between two flanges.
Figure 2 is a cross-sectional view taken along line
2-2 of Figure 1.
Figure 3 is a cross-sectional view taken along line
3-3 of Figure 2,
Figure 4 is an elevational end view of a butterfly
valve mounted on one flange. .
Figure 5 is a cross-sectional view taken along line
5-5 of Figure 4.
The wafer type butterfly valve illustrated as one
embodiment of the present invention in Figures l, 2 and 3 has
a narrow valve body 10. The valve body 10 has flat, parallel
mounting surfaces 11, 12 on each side and a circular flow
opening or central bore 13 therethrough between the surfaces
11, 12 The valve has a circular closure disc 14 rotatably
mounted within the bore 13~ The disc 14 is fixed to a shaft
15 which projects up from within the central bore 13 through
a sleeve 16 in a neck 17 on the valve body 10 for connection
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with a control handle (not shown)0 As shown a resilient,
cylindrical liner 18 is mounted within the central bore 13.
The disc 14 sits tightly on the inner surface 19 of the liner
18. The sides 20 of the liner 18 project slightly outside the
surfaces 11, 12 of the valve body 10 to provide a tight seal
when the valve is mounted between flanges.
The valve body 10 has a set of mounting holes 21 ex-
tending between the surfaces 11, 12. The mounting holes 21
are threaded, over their entire length. The holes 21 are ar-
10 ranged on a circle 22 concentric about the central bore 13. .
The holes 21 are preferably equally spaced about the circle
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22. Four such holes 21, spaced 90 apart are shown. This
number of mounting holes is satisfactory for valves up to
eight inches in diameter. For larger valves up to twelve -
inches in diameter, six mounting holes equally spaced apart
on circle 22 are required. A standard flange has a predetermined
number of standard holes equispaced about a circleO As an
example four to eight inch standard flanges have eight holes ~ -
equispaced about a circle. Thus four to eight inch valves
have four holes equispaced about the same circle, the holes
matching every second hole in the flange. Ten and twelve inch
flanges have twelve holes equispaced about a circle, thus ten
and twelve inch valves have six holes equispaced about the
same circle, the holes matching every second hole in the flanges.
The valve body 10 has gaps at the circle 22 to allow
long bolts to by-pass the valve body without connecting to
the body, when mounting the valve as will be described These
gaps preferably comprise portions 23 removed from the peri-
pheral edge of the valve body 10 between the mounting surfaces
11, 12. The removed portions 23 allow flange mounting bolts
to pass adjacent the body 10 and still be located on the circle
22. Preferably, a removed portion 23 is located between each
adjacent pair of mounting holes 21. The removed portions 23
can be provided by making the valve body 10 generally square
in shape with the mounting holes 21 located adjacent the ;
corners 24 of the body 10 and the removed portions 23 provided
by the removed segments between the sides of the square shaped
valve body and the periphery of the adjacent flanges
The valve is adapted to be mounted between the end
flanges 25, 26 of conduits or pipes 27, 28 respectively as
shown in Figure 1. Each flange 25, 26 has a number of mounting
holes 29 as shown in Figures 2 and 3, arranged about the circle
22 The number of mounting holes 29 provided in the flanges
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25, 26 is equal in number to the number of mounting holes 21
in the valve body 10 plus the number of removed portions 23 in
the valve body 10, The holes 29 are in line in both flanges
and are equally spaced about the circle 22 to match the spacing
of the mounting holes 21 and the removed portions 23 in the
valve body 10.
Long flange bolts 30 and nuts 31 are provided to
join the flanges 25, 26 together with the valve body 10 sand- --
wiched tightly therebetween. These long bolts 30, four of
which are shown, each pass through aligned holes 29 in both
flanges 25, 26 and pass through removed portions 23 of the
valve body 10.
In addition four short lug bolts 32 are passed
through the other mounting holes 29 in the flange 25 and are
threaded into the aligned mounting holes 21 from the surface
of the valve body 10. Another four short lug bolts 33 are
passed through the other mounting holes 29 in the other flange
26 and are threaded into the aligned mounted holes 21 from
the other surface 12 of the valve body 10
The valve body 10 is thus firmly mounted between
the flanges 25, 26 by both the long flange bolts 30 and the
two opposed sets of lug bolts 32, 33.
Either conduit 27, 28 can be replaced without dis-
turbing the valve by removing the long flange bolts 30 and by
removing the lug bolts from one flange of the conduit to be
replaced. The other lug bolts retain the flange of the other
conduit on the valve.
Figures 4 and 5 illustrate the conduit 27 with flange
25 removed from one side of the valve body 10.
Only one set of lug bolts 33 hold the flange 26
to the mounting surface 12 of the valve body 10. The bolts
33 pass through mounting holes 29 in the flange 26 and are
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threaded into mounting holes 21 in the valve body 10.
If desired, the valve body 10 can be provided with
locating shoulders 34 around the gaps or removed portions 23
on the periphery of the valve bodyO The locating shoulders
are shaped to fit around the long flange bolts 30 to locate :~
the valve body 10 during assembly. To assemble the valve
body 10 between two flanges, 25 and 26, the two long flange
bolts 30 are pushed through the two bottom flange mounting
holes 29 on both flanges, and the valve body 10 then set down
between the flanges 25, 26 to sit on the bottom flange bolts
30 with the bottom locating shoulder 34 bearing against the
bottom flange bolt 30. The valve body 10 may then be pivoted
about the bottom flange bolt 30, and the top flange bolt 30
positioned aligning up with the upper locating shoulder 34.
The mounting holes in the flanges 25, 26 and the valve body
10 are then aligned, and the remainder of the flange bolts
30 and lug bolts 32, 33 may then be inserted and tightened
to seal the system.
