Tight shut-off valve with flow control element

A flow control apparatus for use primarily in plug-type and ball-type valves provides means for continuously varying the flow rate of fluid through the valve while using the same operator that is used to control the open and closed position of the valve. The upper trunnion is integrally connected to a butterfly member and connected to the plug by a mechanical linkage comprising a latch rod and a roller latch with corresponding detents in the valve body and upper trunnion, respectively. The butterfly member controls the fluid flow with the plug in the open position in response to 90 degrees of overtravel in the same operator that controls the position of the plug.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates generally to tight shut-off valves such as 
plug valves or ball valves and more specifically, to such valves which 
also have a flow control element mounted in the waterway of the plug valve 
or the ball valve to provide a flow control capability for modulating flow 
in the opened position of the valve. 
Prior Art 
Typically, conventional plug valves or ball valves provide a tight shut-off 
capability designed either to prevent total flow through the valve in one 
configuration or provide for 100% of flow through the valve in the other 
configuration. By way of example, one such valve is disclosed in U.S. Pat. 
No. 3,011,513 which describes a twin seal plug valve capable of double 
block and bleed performance. Such a prior art valve is designed to 
completely shut-off the flow of fluid through the valve when the 
passageway through the plug is oriented at 90 degrees with respect to the 
connecting inlet and outlet pipes. Furthermore, such prior art valves are 
designed to permit 100% flow through the valve when the plug passage is 
oriented coaxially with the inlet and outlet pipes. Such valves are not 
designed to provide a means for controlling the flow rate of the fluid 
through the valve in the open position whereby the flow of fluid through 
the valve is in the range between the closed and fully opened position 
such as where the fluid flow rate would be for example only 50% of the 
maximum flow rate capability of the valve. 
There is prior art which discloses means for controlling the flow rate of a 
plug-type or ball-type valve so that the maximum flow rate can be limited 
to be less than the capability of the valve in its fully opened position. 
However, there does not appear to be any prior art which permits such 
control in a continuously variable configuration which allows simple and 
expedient changes in the flow rate through the valve element using the 
operator that would normally be used to control the open and close 
position of the valve. By way of example, U.S. Pat. No. 2,140,292 to 
Jensen discloses means for providing a fixed maximum flow regulating 
orifice that is concentric with the main shut-off plug. However, Jensen 
does not provide for continuous modulation of the secondary control 
element by the common valve operator after the main shut-off plug has 
reached the full open position. Similarly, U.S. Pat. No. 3,526,249 to 
Baustian discloses a control valve which has an adjustable "preset" 
maximum opening but again does not disclose a continuously variable 
secondary element within the main blocking plug directly operable by means 
of the same main operator that controls the opened and closed position of 
the plug itself. Thus, although the prior art provides various valve 
designs which permit a form of flow control in a plug or ball-type valve, 
the relatively fixed configuration of each such flow control scheme still 
leaves a substantial need for a valve design which permits convenient and 
readily accessible flow control variation in such a valve using the same 
operator that the user would otherwise employ to open and close the valve 
in its conventional configuration. 
SUMMARY OF THE INVENTION 
The present invention provides means for operating a flow control element 
such as a butterfly member that is mounted in the waterway of a plug or a 
ball valve by means of a roller latch between the upper trunnion and the 
plug to maintain a fixed relationship between the plug and the trunnion 
during normal turning of the element and then to subsequently allow rotary 
motion between the plug and the trunnion in an overtravel of 1/4 turn. The 
overtravel provides a means for modulating a variable open position of the 
flow control element with respect to the plug waterway, the flow control 
element being directly attached to the upper trunnion. The resultant valve 
provides a flow control valve element concentrically within a tight 
shut-off plug or ball-type valve wherein the control valve portion may be 
operated with no modification to the rotary valve operators with the 
exception of insuring that there is an additional 90 degrees or other 
required rotary travel of the rotary operator to modulate the flow control 
element in the overtravel position. The invention thus provides an added 
unique capability for continuous flow variation control in the open 
position of the valve with little or no change in the external 
configuration of the valve and with a simple low-cost but yet elegant 
improvement implemented entirely within the interior of the valve thereby 
giving the user an additional capability at relatively trivial additional 
cost. 
OBJECTS OF THE INVENTION 
It is therefore a principal object of the present invention to provide a 
flow control valve concentrically within a tight shut-off plug or 
ball-valve which control valve portion may be operated with no 
modification to rotary valve operators with the exception on insuring that 
there is an additional 90 degrees or other required rotary travel of the 
rotary operators to modulate the flow control element in the overtravel 
position. 
It is an additional object of the present invention to provide a tight 
shut-off valve of the type having a plug or ball therein for opening 
and/or closing the valve to the flow of fluid therethrough and which valve 
comprises an improvement consisting of a flow control element mounted in 
the waterway of the plug or ball valve element to permit continuous flow 
control variation of the valve in its open position. 
It is still an additional object of the present invention to provide an 
improved plug or ball valve having a flow control element such as a 
butterfly mounted in the waterway of the plug or ball element by means of 
a roller latch between the upper trunnion and the plug or ball to maintain 
a fixed relationship between the plug or ball and the trunnion during the 
normal 1/4 turn and then to allow rotary motion between the plug and the 
trunnion is an overtravel extension of the 1/4 turn for the purpose of 
modulating a variable open position of the flow control element with 
respect to the plug waterway, the flow control element being directly 
attached to the upper trunnion. 
It is still an additional object of the present invention to provide a 
combined flow control and double block and bleed valve in which the flow 
control portion of the invention is provided for permitting the user to 
continuously vary the fluid flow rate through the valve in its open 
position without requiring any substantial modification to the external 
configuration of the valve or to the rotary valve operator associated with 
the valve.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring first to FIG. 1 it will be seen that a typical plug valve 10 of 
the prior art comprises a valve body 12 having an inlet 14 and an outlet 
16. The valve body 12 encloses a plug 18 through which there is a flow 
passage 20 which is designed to mate with inlet and outlet passages 22 
when the valve is configured in its open configuration as shown in FIG. 1. 
Plug 18 may by way of example, be configured to operate in conjunction 
with a pair of slips 24 which enable low friction rotation of the plug 
within the valve body and also provide for a double block and bleed 
capability when the valve is in its closed position. Plug 18 is positioned 
within the valve body 12 for rotation therein coaxially with an upper 
trunnion 26 and a lower trunnion 30. Upper trunnion 26 is typically 
connected to a valve stem 28 which is in turn connected to the operator 
mechanism (not shown) which is provided for either manual or automated 
operation of the valve between its open and closed configurations. 
One significant limitation of the prior art valve of FIG. 1 is that it is 
designed to operate in either a closed or open mode and it is not 
configured to operate in a flow control mode wherein there is flow but 
less than the maximum flow capacity of the valve. 
The present invention is a highly significant and advantageous improvement 
on valves of the type shown in FIG. 1 in which the capability for flow 
control in the open position of the valve is provided with a minimum of 
structural modification to the valve and in which the flow control 
capability provided by the invention is one of continuously variable 
control in which the user can readily obtain virtually any flow rate he 
wishes between zero and maximum using the same operator he would otherwise 
use to open and close the valve. Thus, the improved plug 32 of FIG. 2 also 
includes slips 33 and a flow passage 34 and is also designed to be 
interfaced with the valve body by means of an upper trunnion 36 and a 
lower trunnion 38. However, plug 32 also includes a novel butterfly valve 
40 which is positioned within the passage 34 and which is adapted to 
rotate about the axis of the trunnions 36 and 38 whereby to permit 
selective control over the effective aperture of passage 34 depending upon 
the relative position of butterfly valve 40 within the passage. Thus for 
example, in the view provided by FIG. 2, the butterfly valve 40 is 
positioned at approximately 45 degrees with respect to the axis of flow 
passage 34 thereby to permit the flow of fluid through the valve but at a 
substantially reduced rate as compared to the maximum flow rate of the 
plug passage without the butterfly or with the butterfly in a fully open 
position. The details of the butterfly valve interface with the 
conventional elements of the valve of FIG. 1 along with its operational 
sequence will now be discussed in conjunction with FIGS. 3 and 4. 
Referring to FIG. 3 it will be seen that the plug 32, butterfly 40 and flow 
passage 34 are shown in a rectangular configuration for purposes of 
illustrating that the present invention may be implemented in a variety of 
different geometrical shapes to accommodate the conventional 
configurations of most plug valves and ball valves. Furthermore, as 
illustrated at the bottom-most portion of FIG. 3, the lower trunnion of 
the valve of the present invention may be of the conventional 
configuration as illustrated by trunnion 38 or of the inverted trunnion 
configuration as illustrated by trunnion 38a. In either case, the upper 
trunnion 36 is detached from the plug 32 and passes through the flow 
passage 34 which is occupied by the substantially congruent butterfly 
valve 40 which is integral to the upper trunnion 36 within the passage. 
Plug 32 is provided with a channel 41 in which there is positioned a latch 
rod 42 for slideable repositioning therein. The valve body 45 adjacent the 
channel 41 is provided with a body detent 44 which is adapted to receive 
one end of the latch rod 42. The area of plug 42 immediately adjacent the 
upper trunnion 36 is provided with a latch chamber 46 in which there is 
positioned a roller latch 48 which is adapted to be received by a trunnion 
detent 50 in upper trunnion 36. 
During conventional operation of the plug 32, latch rod 42 is not aligned 
with body detent 44 and therefore, rod 42 is in a position to force roller 
latch 48 into the trunnion detent 50. In this configuration, upper 
trunnion 36 and plug 32 rotate as an integral unit and as a result, 
rotation by the operator of the valve rotates the plug in a conventional 
manner. However, when latch rod 42 is aligned with body detent 44 the rod 
is forced into the detent thereby releasing the roller latch 48 from the 
trunnion detent 50. This action frees the upper trunnion 36 from its 
linkage to the plug 32 thereby allowing upper trunnion 36 and integral 
butterfly valve 40 to rotate independently of plug 32. It is in this 
configuration that the flow control portion of the present invention comes 
into play, permitting the user to vary the flow rate depending upon the 
angle of the butterfly valve 40 relative to the axis of the flow passage 
34. 
Thus, in the view provided by FIG. 3 the latch rod 42 is substantially 
aligned with body detent 44. This would occur after the plug has been 
rotated so that flow channel 34 has been aligned with the corresponding 
flow channels of the inlet and outlet as will be seen hereinafter. Pending 
further rotation of the upper trunnion 36 in this configuration, butterfly 
valve 40 is substantially perpendicular to flow channel 44 thereby 
continuing to substantially block the flow through the plug 32. However, 
further counterclockwise rotation of upper trunnion 36 as shown in FIG. 3 
releases the roller latch 48 from the trunnion detent 50 as previously 
described thereby permitting rotation of just the butterfly valve 40 for 
permitting controlled increase in the flow rate through the flow passage 
34. Channel 41 may preferably be enlarged in diameter at 41a to permit use 
of a bias spring 54 to force latch rod 42 out of body detent 44 as soon as 
roller latch 48 engages detent 50. Spring 54 is retained between a ring 52 
on rod 42 and a washer 56, the latter being retained in an annular recess 
58. 
The present invention preferably includes structure shown in FIGS. 3, 3a 
and 3b designed to ensure that valve 40 and plug 32 move either together 
or independently during opening and closing as required during each 
portion of the respective cycles. More specifically, as seen in FIGS. 3 
and 3a, a valve bonnet 35 overlies plug 32 and is provided with a pin 43 
extending downwardly from a recess 37. Plug 32 is provided with an arcuate 
groove 39 of approximately 90 degrees arch and adapted to receive pin 43. 
In this manner, when the plug 32 and valve 40 have been rotated together 
to the point where flow channel 34 is properly positioned for flow 
therethrough, the interaction of pin 43 and groove 39 prevents further 
rotation of the plug 32 while permitting further rotation of valve 40. 
Similarly, flow channel 34 in plug 32 is provided with a shoulder 51 shown 
in FIG. 3b and designed to engage an edge of valve 40. Accordingly, when 
the valve is rotated to block flow channel 34 during closing, the valve 
engages the shoulder 51 whereby further rotation of trunnion 36 must 
thereafter rotate both the valve 40 and plug 32 in unison. The action of 
the valve of the present invention in conjunction with the butterfly 
portion thereof will now be described in more detail in conjunction with 
FIGS. 4a through 4c. 
More specifically, referring now to FIGS. 4a, 4b and 4c it will be seen 
that in the configuration of the invention shown in FIG. 4a, the plug 32 
is in its closed configuration with flow passage 34 oriented substantially 
perpendicular to the inlet passage 47 and outlet passage 49. In this 
configuration, slips 33 are positioned in facing relation to passages 47 
and 49 thereby providing a double block configuration preventing flow 
through the valve and allowing maintenance personnel to bleed the valve if 
desired for maintenance purposes. As further seen in FIG. 4a, in the 
closed configuration of the valve, latch rod 42 is entirely contained 
within the plug 32 thereby forcing roller latch 48 into the trunnion 
detent 50 of upper trunnion 36. In this configuration, as previously 
described in conjunction with FIG. 3, the upper trunnion 36 and the 
remaining portions of plug 32 are in effect integrated by the mechanical 
interconnection through roller latch 48 and therefore rotational force 
imparted to upper trunnion 36 by means of the valve operator will cause 
the entire plug 32 to rotate. Furthermore, as seen in FIG. 4a, butterfly 
valve 40 is aligned with the channel 41 coaxially with the flow axis of 
inlet 47 and outlet 49. 
Upon counterclockwise rotation of upper trunnion 36 through a 90 degree 
angle, the valve configuration becomes that represented by FIG. 4b. More 
specifically, as seen in FIG. 4b, plug 32 has now been rotated 90 degrees 
whereby flow channel 34 is aligned with the inlet 47 and the outlet 49. 
Under normal conditions for conventional prior art plug and ball valves, 
the configuration of FIG. 4b would permit maximum fluid flow through the 
valve. However, the present invention is configured whereby butterfly 
valve 40 is now aligned perpendicularly with respect to the inlet 47 and 
the outlet 49 thereby substantially blocking all flow through the valve. 
The configuration of FIG. 4b is substantially that of FIG. 3 previously 
described wherein latch rod 42 and channel 41 are now aligned with body 
detent 40 adjacent plug 32. In this configuration as previously described 
in conjunction with FIG. 3, latch rod 42 is free to enter detent 44 
thereby releasing roller latch 48 from trunnion detent 50 and disengaging 
the upper trunnion 36 from the remaining portions of the plug 42. However, 
the butterfly valve 40, being integral to the upper trunnion 36, is still 
free to rotate with rotation of the upper trunnion and this is precisely 
what occurs next as shown in FIG. 4c. 
More specifically, as seen in FIG. 4c, upper trunnion 36 has now been 
rotated approximately 45 degrees counterclockwise beyond the rotational 
position of FIG. 4b. Because of the interaction between latch rod 42 and 
body detent 44, plug 32 has remained fixed during the further rotation of 
upper trunnion 36. However, the butterfly valve 40, being affixed to upper 
trunnion 36, has rotated through the same angle of approximately 45 
degrees thereby permitting a selected limited fluid flow through the flow 
passage 34 of plug 32 while still preventing maximum flow. Clearly, 
further counterclockwise rotation of upper trunnion 36 until the trunnion 
has been rotated an additional 90 degrees counterclockwise from the 
position shown in FIG. 4b, would place the butterfly valve in a position 
substantially parallel to the flow axis through inlet 47 and outlet 49 as 
well as flow passage 34 thereby permitting substantially maximum flow of 
the fluid through the plug 32. 
When the valve is to be closed the sequence illustrated in FIGS. 4a, 4b and 
4c is reversed and the upper trunnion 36 is caused to rotate in a 
clockwise direction thereby first reorienting butterfly valve 40 in a 
position substantially perpendicular to the flow axis through the valve 
until the valve reassumes the configuration shown in FIG. 4b. At this 
point, further rotation of upper trunnion 36 in a clockwise direction will 
cause latch rod 42 to be released from body detent 44 thereby causing the 
latch rod 42 to move towards the upper trunnion 36 and causing the roller 
latch 48 to again engage the trunnion detent 50 within upper trunnion 36. 
Further clockwise rotation of upper trunnion 36 causes the plug 32 to also 
rotate in the same direction until the plug reassumes its closed 
configuration of FIG. 4a. Because of the interaction of valve 40 and 
shoulder 51 as described above in conjunction with FIG. 3b, valve 40 and 
plug 32 are thereafter interlocked and detent 50 and latch cannot force 
rod 42 back toward body detent 44 during the remainder of the closing 
cycle after the valve 40 is rotated to the position of FIG. 4b. 
Those having skill in the art to which the present invention pertains will 
understand that in addition to the rotational motion of upper trunnion 36 
described in conjunction with FIGS. 3 and 4, there may be vertical 
movement thereof in association with the interaction between the plug 32 
and the slips 33. Such vertical motion of trunnion 36 may for example be 
of the type shown in the upper-most portion of FIG. 1 for a seat and 
reseat valve in which a plug moves upwardly for rotation and again 
downwardly for being reseated in its open position. On the other hand, it 
may be of the type wherein the plug moves only upwardly into the open 
position for rotation or downwardly into the closed position subsequent to 
rotation in the opposite direction. In either case, it will be understood 
that the operator with which the present invention may be used would be of 
conventional design with regard to the vertical motion and conventional 
rotational motion of upper trunnion 36, and need only be provided with the 
added capability of the overtravel of 90 degrees beyond the opened 
position of the plug whereby to control the position of butterfly valve 
40. 
It will now be understood that what has been disclosed herein comprises a 
novel flow control element for a plug-type or ball-type valve which 
permits continuous control of the flow rate of the fluid through such 
valves while utilizing the same operating mechanism that is conventionally 
used for controlling the open and closed position of the valve. The flow 
control portion of the invention comprises a butterfly valve that is made 
integral to the upper trunnion. The upper trunnion is affixed to the plug 
by means of a mechanical linkage comprising a latch rod and roller latch 
during the opening and closing of the plug of the valve in a conventional 
manner. However, the upper trunnion is mechanically disengaged from the 
plug during the overtravel portion of the operation of the valve whereby 
to control the position of the butterfly valve relative to the plug 
passageway for continuously varying the level of flow through the 
passageway while the plug is in its open position. 
Those having skill in the art to which the present invention pertains will, 
as a result of the applicant's teaching herein, now perceive of various 
additions and modifications which may be made to the invention. By way of 
example, other butterfly valve geometries and shapes as well as 
alternative means for engaging and disengaging the upper trunnion with the 
plug will now occur to those who have had the benefit of the applicant's 
teaching herein. However all such modifications and additions are deemed 
to be within the scope of the invention which is to be limited only by the 
claims appended hereto.