Shutoff-opening devices and fluid control apparatus comprising such devices

A valve main body is internally formed with a main channel extending from a rear end face thereof nearly to a first valve actuator, and two subchannels communicating with the main channel via second and third valve actuators, respectively. The valve main body has a slanting face extending forwardly downward and having the first valve actuator mounted thereon.

BACKGROUND OF THE INVENTION 
The present invention relates to shutoff-opening devices comprising a valve 
main body and a plurality of valve actuators and fluid control apparatus 
comprising such devices. 
The terms front, rear, upper, lower, right and left are herein used based 
on FIG. 2; the right-hand side, the left-hand side, the upper side and 
lower side of the drawing are referred to as front, rear, upper and lower, 
respectively, and the terms right and left are used for the device as it 
is viewed from the behind toward the front. The device may be used with 
the front-rear relationship as reversed, or the upper and lower side 
thereof positioned as the left and right sides. 
Shutoff-opening devices are already known which comprise a rectangular 
parallelepipedal valve main body, and a plurality of valve actuators. Such 
a device is disposed at each of the inlet side and the outlet side of a 
massflow controller, or like controller, to provide a fluid control 
apparatus for use in semiconductor manufacturing equipment. 
FIG. 17 shows a conventional shutoff-opening device 61. The device 61 
comprises a rectangular parallelepipedal valve main body 63, and three 
valve actuators 64, 65, 66 mounted on the upper surface of the main body 
and arranged side by side longitudinally thereof (in the front-rear 
direction). The valve main body 63 is formed with a main channel 67 
extending from the rear end face of the body 63 nearly to the front-end 
valve actuator 64, and three subchannels 68, 69, 70 communicating with the 
main channel 67 via the actuators 64, 65, 66, respectively. The upper 
surface of the valve body 63 is flat and parallel to the lower surface 
thereof. The actuators 64, 65, 66 are mounted on the flat surface, and 
spaced apart by equal distances. 
When a fluid flows from the main channel 67 into the first subchannel 68, 
the dead volume (stagnant portion of fluid) of the device 61 is only short 
channels 71, 72 connecting the main channel 67 to the second and third 
actuators 65, 66. When the fluid flows from the main channel 67 into the 
second channel 69, the dead volume is the short subchannel 72 
interconnecting the main channel 67 and the third valve actuator 66, and 
front end portions 67a, 67b of the main channel 67 positioned between the 
first valve actuator 64 and the second valve actuator 65. Further when the 
fluid flows from the main channel 67 into the third subchannel 70, the 
dead volume is the short channel 71 interconnecting the main channel 67 
and the second valve actuator 65, the main channel front end portions 67a, 
67b positioned between the first and second valve actuators 64, 65, and an 
intermediate portion 67c of the main channel 67 positioned between the 
second end third actuators 65, 66. 
With the shutoff-opening devices and fluid control devices for use in 
semiconductor manufacturing equipment, it is critical to diminish the dead 
volume which reduces the purity of the process gas. It is also required 
that these devices be reduced in content volume, entire volume and weight, 
whereas the conventional devices still remain to be improved in these 
points. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide shutoff-opening devices 
which are diminished in dead volume, volume and weight as compared with 
conventional devices and to provide fluid control devices comprising such 
shutoff-opening devices. 
The present invention provides a shutoff-opening device comprising a 
generally rectangular parallelepipedal valve main body, and a plurality of 
channel on-off valve actuators mounted-on an upper surface of the valve 
main body and arranged side by side longitudinally thereof, the valve main 
body being internally formed with a main channel extending from a rear end 
face of the main body or a rear end portion lower surface of the main body 
nearly to the valve actuator at a front end of the main body, and with a 
plurality of subchannels communicating with the main channel via the 
respective valve actuators, the shutoff-opening device being characterized 
in that the surface of the valve main body includes a slanting face 
extending forwardly downward and having the front-end valve actuator 
mounted thereon. 
The forwardly downward inclination of the slanting face is preferably 15 
degrees to 60 degrees, more preferably 20 degrees to 45 degrees. If the 
inclination is small, the advantage resulting from this feature is small, 
whereas if the inclination is great, the front-end valve actuator becomes 
forwardly projected beyond the front end of the valve main body, 
increasing the possibility of the actuator interfering with other members. 
Thus, the inclination should be within the preferred range described in 
view of the size of the valve actuators and the size of the fluid control 
apparatus to be provided by such shutoff-opening devices. 
With the shutoff-opening device of the present invention, the upper surface 
of the valve main body is in the form of a slanting face extending 
forwardly downward at the portion thereof having the front-end valve 
actuator mounted thereon. This reduces the volume of the front upper 
portion of the valve main body, the front-to-rear length of the front 
portion thereof, and the content volume, volume and weight of the 
shutoff-opening device. The main channel includes a front end portion 
positioned between the front-end valve actuator and the valve actuator 
immediately adjacent thereto which portion accounts for a major portion of 
the dead volume of the shutoff-opening device. This main channel front end 
portion diminishes with the reduction in the length of front portion of 
the valve main body, consequently decreasing the dead volume of the 
shutoff-opening device. 
The shutoff-opening device is provided, for example, at each of the inlet 
side and the outlet side of a massflow controller, or like controller, to 
constitute a fluid control device for use in semiconductor manufacturing 
equipment. 
Among the subchannels of each shutoff-opening device in this case, it is 
desired to use the subchannel remotest from the controller for the process 
gas and to use the subchannel adjacent to this subschannel for a purge 
gas. The dead volume during the flow of the process gas is then limited to 
a short channel or short channels connecting the main channel to the other 
valve actuator or actuators toward the rear, with the result that the gas 
remaining upon changing over the process gas to other gas can be removed 
within a short period of time. 
A suitable number of fluid control devices of the type described are used 
for providing a fluid control apparatus. It is desired in this case that 
the valve main bodies of the shutoff-opening devices be equal in 
front-to-rear length irrespective of the number of valve actuators. The 
first valve actuators of the shutoff-opening devices are then aligned, 
rendering the shutoff-opening devices easy to operate. 
Preferably, the subchannel included in the subchannels of each 
shutoff-opening device and communicating with the main channel via the 
front-end valve actuator has an opening formed in a front end face or 
lower surface of the valve main body, the other subchannel or subchannels 
have an opening in the lower surface of the valve main body, and piping 
for the other subchannel or subchannels is provided under the main body. 
The piping means can then be in a flat arrangement under the valve main 
body, compacting the control apparatus in its entirety and assuring the 
piping portion of facilitated maintenance.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Embodiments of the invention will be described below with reference to the 
drawings. 
FIGS. 1 and 2 show a first embodiment of shutoff-opening device 1 of the 
invention. As shown in FIGS. 3 and 4, the shutoff-opening device 1 is 
disposed at the inlet side and the outlet side of a massflow controller 2 
to provide a fluid control device 10. 
With reference to FIGS. 1 and 2, the shutoff-opening device 1 comprises a 
generally rectangular parallelepipedal valve main body 3, and first 
(front-end), second (intermediate) and third (rear-end) channel 
opening-closing valve actuators 4, 5, 6. The valve main body 3 is 
internally formed with a main channel 21 extending straight from the rear 
end face of the main body 3 nearly to the location of the front-end valve 
actuator 4 longitudinally of the body, and first (front-end), second 
(intermediate) and third (rear-end) subchannels 22, 23, 24 communicating 
with the main channel 21 via the valve actuators 4, 5, 6, respectively. 
The subchannels 23, 24 communicating with the main channel 21 via the 
respective second and third valve actuators 5, 6 are positioned 
immediately in the rear of respective short channels 25, 26 extending from 
the main channel 21 to the second and third valve actuators 5, 6, whereas 
these subchannels 23, 24 are shown in broken lines as shifted leftward 
from the actual locations (the same as hereinafter). 
The valve main body 3 is integral with a blocklike extension 7 extending 
from a right wall 3c of the portion thereof having the actuators 4, 5, 6 
attached thereto. The extension 7 is formed with the second and third 
subchannels 23, 24 and serves as a screw fastening portion. 
The upper surface of the valve main body 3 includes a mount face 3a in the 
form of a slanting face extending forwardly downward for mounting the 
front-end actuator 4 thereon. The remaining portion of the upper surface, 
i.e., a mount face 3b for the second and third actuators 5, 6, is flat and 
parallel to the lower surface of the body 1. 
The valve actuators 4, 5, 6 are attached to the mount faces 3a, 3b 
perpendicular thereto. The valve main body 3 has a cavity 18 for inserting 
the first actuator 4, and cavities 19 for inserting the respective second 
and third actuators 5, 6. The cavity 18 has a smaller depth than the 
cavities 19. Accordingly, the first actuator 4 is shorter than the other 
actuators 5, 6. The valve actuators can be of the same length for 
insertion into cavities of the same depth. The first and third actuators 
4, 6 are of the normally closed type, and the second actuator 5 of the 
normally open type. 
The main channel 21 extends from the rear end face of the main body 3 to a 
location close to the front end face thereof. The first subchannel 22 has 
an opening in the front end face of the body 3. The front end face of the 
main body 3 is provided with a fitting 9 having a nut for connecting a 
check valve, pressure regulator, or the like, to the first subchannel 22. 
The second and third subchannels 23, 24 extend through the extension 7 of 
the main body 3 and each have an opening in the lower surface of the body 
3. 
With reference to FIG. 2, the dead volume of the device 1 is only the short 
channels 25, 26 connecting the main channel 21 to the respective second 
and third valve actuators 5, 6 when a fluid flows from the main channel 21 
into the first subchannel 22. When the fluid flows from the main channel 
21 into the second subchannel 23, the dead volume is the short channel 26 
connecting the main channel 21 to the third actuator 6, and front end 
portions 21a, 21b of the main channel 21 which are positioned between the 
first and second actuators 4, 5, forming an obtuse angle. when the fluid 
flows from the main channel 21 into the third subchannel 24, the dead 
volume is the short channel 25 connecting the main channel 21 to the 
second actuator 5, the main channel front end portions 21a, 21b positioned 
between the first and second actuators 4, 5, and an intermediate portion 
21c of the main channel 21 positioned between the second and third 
actuators 5, 6. 
With the shutoff-opening device 1 described, the first actuator mount face 
3a included in the upper surface of the valve main body 3 is made equal in 
area to the first actuator mount face 63a of the conventional 
shutoff-opening device 61 shown in FIG. 17. Accordingly, the volume of the 
front upper portion of the valve main body 3 and the front-to-rear length 
of the front portion of the body are made smaller than in the conventional 
shutoff-opening device 61 by an amount attributable to the formation of 
the forwardly downward slanting face serving as the mount face 3a, 
consequently diminishing the content volume, overall volume and weight of 
the shutoff-opening device 1. Suppose the length of the first valve 
actuator mount face 63a of the conventional shutoff-opening device 61 is 
L, and the inclination of the slanting face is .theta.. The 
shutoff-opening device 1 is reduced by L(1-cos .theta.) in front-to-rear 
length, and by L.sup.2 .times.cos .theta..times.sin .theta..times.2 in 
vertical section. With respect to the dead volume, the combined volume of 
the obtuse angle forming front end portions 21a, 21b of the main channel 
21 is made smaller than the combined volume of the front end portions 67a, 
67b of the main channel 67 of the conventional shutoff-opening device 61 
owing to the reduction in the length of the valve main body 3, whereby the 
dead volume of the entire shutoff-opening device 1 is also diminished. As 
the inclination increases, the front end portion 21a extending straight 
from the portion 21c of the main channel 21 diminishes with an increase in 
the length of the bent front end portion 21b. However, the diminution of 
the overall dead volume increases with an increase in the inclination. 
FIGS. 3 and 4 show a fluid control device, which comprises a massflow 
controller 2, and the shutoff-opening device 1 installed at each of the 
inlet side (left side in FIG. 4) and the outlet side (right side in FIG. 
4). The shutoff-opening device 1 shown in FIGS. 1 and 2 is mounted on the 
inlet side with their front and rear ends reversed. 
With the shutoff-opening device 1 at the inlet side, the first subchannel 
22 remotest from the massflow controller 2 is used for the inflow of 
process gas, the second subchannel 23 adjacent to the subchannel 22 for 
the inflow of purge gas, and the third subchannel 24 closest to the 
controller 2 for evacuation. With the shutoff-opening device 1 at the 
outlet side, the first subchannel 22 remotest from the controller 2 is to 
communicate with a process chamber, and the second subchannel 23 with an 
exhaust gas duct to serve as a purge port. 
An upper channel block 11 having a channel 11a opened at its lower surface 
is provided in a projecting manner at the lower end of each of the inlet 
and outlet sides of the massflow controller 2. A lower channel block 12 is 
disposed beneath the block 11. The lower and upper channel blocks 12, 11 
are fastened together by two controller installing screws 13 screwed into 
the upper block 11 from above. The lower block 12 is formed with a channel 
12a for holding the channel 11a of the upper block 11 in communication 
with the main channel 21 of the valve main body 3. The lower block 12 is 
fastened to the valve main body 3 with device installing screws 14 driven 
in through the lower block 12. Piping channel blocks 15, 16 for the 
respective second and third subchannels 23, 24 are fastened to the 
extension 7 with piping installing screws 17 driven in through the 
extension 7 from above. The third subchannel 24 of the inlet-side 
shutoff-opening device 1 and the third subchannel 24 of the outlet-side 
shutoff-opening device 1 are connected to a vacuum pump (not shown) after 
their piping channel blocks 15, 15 are interconnected by a pipe 27. A 
fitting 28 is attached to the lower side of the block 16 for the second 
subchannel 23. The fitting 28 has a pipe joint portion which is positioned 
at a lower level than the evacuation pipe 27. The purge gas piping is 
therefore unlikely to interfere with the evacuation pipe 27. When the 
fluid control device 10 is to be installed, the massflow controller 2 and 
the shutoff-opening devices 1 are mounted on the upper surface of a base 
plate 29 with the piping channel blocks 15, 16 positioned beneath the 
lower surface of the base plate 29 as shown in FIG. 4. 
If the massflow controller 2 of the fluid control device 10 malfunctions, 
the controller 2 is removable upward for replacement by removing the 
controller installing screws 13. Further if the shutoff-opening device 1 
fails, the device 1 can be removed upward for replacement by removing the 
device installing screws 14 and the piping installing screws 17. 
When the process gas flows through the fluid control device described, the 
dead volume is limited only to the short channels 25, 26 connecting each 
main channel 21 to the corresponding second and third valve actuators 5, 
6. 
FIG. 5 shows a second embodiment of shutoff-opening device 31 of the 
invention. The shutoff-opening device 31 is provided at each of the inlet 
side and outlet side of a massflow controller 2 to constitute a fluid 
control device 40 as seen in FIG. 6. This shutoff-opening device 31 is 
different from the shutoff-opening device 1 of the first embodiment in 
that a first subchannel 32 has an opening in the lower surface of a valve 
main body 33. Throughout the drawings showing the first and second 
embodiments, like parts are designated by like reference numerals and 
symbols and will not be described repeatedly hereinafter. With reference 
to FIG. 5, the fitting 9 at the front end of the valve main body 3 shown 
in FIG. 1 is removed, and the main body 33 has a blocklike extension 34, 
which is formed with the first subchannel 32 which has an opening in the 
lower surface of the valve main body, in addition to the second and third 
subchannels 23, 24. As seen in FIG. 6, the extension 34 has connected 
thereto a piping channel block 35 communicating with the first subchannel 
32, in addition to the piping channel blocks 15, 16 in communication with 
the respective second and third subchannels 23, 24. A fitting 36 provided 
under this piping channel block 35 has a pipe joint, which is positioned 
at a level intermediate between the evacuation pipe 27 and the fitting 28 
communicating with the second subchannel 23. Accordingly, the process gas 
piping is unlikely to interfere with the purge gas piping or the 
evacuation pipe 27. 
Although the shutoff-opening devices 1 shown in FIGS. 1, 2 and 5 have three 
valve actuators 4, 5, 6, two actuators are used when there is no need for 
the evacuation subchannel 24. In this case, the third valve actuator 6 is 
of course eliminated with the front-to-rear length of the valve main body 
shortened, whereas FIG. 7 shows a valve main body 43 which has the same 
length as the foregoing embodiments but which is formed with neither of 
the cavity 19 for inserting the third actuator 6 and the evacuation 
subchannel 24. 
FIG. 7 shows a shutoff-opening device 41, which comprises a generally 
rectangular parallelepipedal valve main body 43, and first (front-end) and 
second valve actuators 4, 5 mounted on the upper surface of the main body 
43 and arranged side by side longitudinally thereof (front-rear 
direction). The main body 43 is internally formed with a main channel 21 
extending from the rear end face of the body 43 to a location near the 
front end thereof, and first (front-end) and second subchannels 22, 23 
adapted to communicate with the main channel 21 under the control of the 
respective actuators 4, 5. The upper surface of the valve main body 43 
includes a mount face 43a in the form of a slanting face extending 
forwardly downward and having the front-side first actuator 4 mounted 
thereon. The other portion of the surface, i.e., mount face 43b, is flat 
and parallel to the lower surface of the body 43. The flat face 43b has 
such an area that two valve actuators can be mounted thereon. The front 
half of the flat face 43b has the second actuator 5 mounted thereon. 
A pressure sensor can be mounted on the portion of the shutoff-opening 
device shown in FIG. 7 at the portion from which the third actuator 6 is 
removed as shown in FIG. 8. With reference to FIG. 8, a shutoff-opening 
device 51 thus adapted comprises a generally rectangular parallelepipedal 
valve main body 53, and first (front-end) and second valve actuators 4, 5 
mounted on the upper surface of the main body 53 and arranged side by side 
longitudinally thereof (front-rear direction). The main body 53 is 
internally formed with a main channel 21 extending from the rear end face 
of the body 53 to a location near the front end thereof, and first 
(front-end) and second subchannels 22, 23 adapted to communicate with the 
main channel 21 under the control of the respective actuators 4, 5. The 
upper surface of the valve main body 53 includes a mount face 53a in the 
form of a slanting face extending forwardly downward and having the 
front-end first actuator 4 mounted thereon. The other portion of the 
surface, i.e., mount face 53b, is flat and parallel to the lower surface 
of the body 53. The flat face 53b has such an area that two valve 
actuators can be mounted thereon. The front half of the flat face 53b has 
the second actuator 5 mounted thereon. The rear half portion is formed 
with a threaded bore 54 for mounting a pressure sensor. The valve main 
body 53 is provided at its front end with a fitting 55 which is externally 
threaded. 
The fluid control devices 10, 40 shown in FIGS. 3, 4 and 6 are used in a 
suitable combination to provide a fluid control apparatus for use in 
fabricating semiconductors. FIG. 9 shows an example of such fluid control 
apparatus. With reference to the drawing, the fluid control device 40 
including shutoff-opening devices 31 each having two valve actuators 4, 5 
is disposed in parallel to the fluid control device 10 including 
shutoff-opening devices 1 each having three valve actuators 4, 5, 6 
without no spacing formed between the two devices 40, 10. Although not 
shown, another similar fluid control device can be disposed in parallel to 
these devices 10, 40 without being spaced apart therefrom. 
Thus fluid control apparatus can be provided wherein these fluid control 
devices 10, 40 are in a planar or flat arrangement, with the first 
actuators 4 of the shutoff-opening devices 1, 31, as well as the second 
actuators 5 thereof, arranged in alignment with one another. Further the 
piping means 15, 16, 27, 26 for the second and third subchannels 23, 24 
are provided under a base plate 29 (rear side of the drawing) without 
increasing the width of the overall control apparatus. These piping 
portions 15, 16, 27, 28 are easy to maintain and appear neat. 
According to the arrangement shown in FIG. 9, the same shutoff-opening 
devices 1 or 31 are disposed at the inlet side and the outlet side of each 
massflow controller 2, and the extensions 7, 8 of the valve main bodies 3, 
33 are provided at left on the inlet side and at right on the outlet side. 
On the other hand, FIG. 10 shows a fluid control apparatus wherein 
extensions 46, 47 of valve bodies 44, 45 at the inlet side and the 
extensions 7, 8 of the valve bodies 1, 31 at the outlet side are similarly 
arranged at right. These inlet-side valve main bodies 44, 45 are 
available, for example, merely by changing the position of the extension 7 
on the right side as shown in FIG. 1 to the left side and causing the main 
channel 21 to communicate with the channels in the interior of the 
extension 7. With this arrangement, the second and third subchannels 23, 
24 are all made to communicate with openings in the underside, while the 
openings are all positioned at the right side of the valve main bodies, 
consequently assuring facilitated piping work. 
When the shutoff-opening devices 1, 31, 41, 51 according to the first to 
fourth embodiments are to be used, lower channel blocks 12 are necessary 
for connecting the massflow controller 2 to the shutoff-opening devices 1, 
31, 51 as shown in FIG. 3 or 6. The lower channel block 12 is fastened to 
the valve main body 3 with the device installing screws 14 driven in 
through the lower block 12 horizontally. In removing the shutoff-opening 
device 1, 31, 41 or 51, these screws 14 and piping installing screws 17 
need to be removed, whereas the removal of the device installing screws 14 
requires a very cumbersome procedure in the case where many control 
devices 10, 40, or 20, 50 have been assembled as arranged in parallel into 
a fluid control apparatus (see FIG. 9 or 10). 
Two embodiments will be described below which ensure facilitated removal of 
the shutoff-opening devices. 
FIGS. 11 and 12 show a fifth embodiment of shutoff-opening device of the 
invention. This shutoff-opening device 101 has the same construction as 
the shutoff-opening device 31 of the second embodiment shown in FIG. 5 
except that a main channel 121 has no opening in a rear end face 103c but 
communicates with an opening formed in the lower surface of a valve main 
body 103 by way of a downward channel 122 provided in the body 103. 
Throughout the drawings showing the first, second and the following 
embodiments, like parts are designated by like reference numerals or 
symbols and will not be described repeatedly. 
With reference to FIGS. 11 and 12, the valve main body 103 is internally 
formed with the above-mentioned main channel 121 which extends from a 
portion close to the rear end of the body 103 nearly to the front end 
thereof, and first (front-end), second (intermediate) and third (rear-end) 
subchannels 32, 23, 24 communicating with the main channel 121 via 
respective valve actuators 4, 5, 6. The main channel 121 has the downward 
channel 122, which extends straight from the rear end of the channel 121 
downward and has an opening in the lower surface rear end portion of the 
body 103. The subchannels 32, 23, 24 extend through a blocklike extension 
34 of the valve main body 103 and are open at the lower surface of the 
body 103. The upper surface of the valve main body 103 includes a mount 
face 103a which is in the form of a slanting face extending forwardly 
downward and having the front-end first valve actuator 4. The other 
portion of the surface is a mount face 103b for the other two second and 
third valve actuators 5, 6. 
With reference to FIG. 12, the dead volume of the shutoff-opening device 
101 is only the short channels 25, 26 connecting the main channel 121 to 
the respective second and third valve actuators 5, 6 when a fluid flows 
from the main channel 121 into the first subchannel 32. When the fluid 
flows from the main channel 121 into the second subchannel 23, the dead 
volume is the short channel 26 connecting the main channel 121 to the 
third actuator 6, and front end portions 121a, 121b of the main channel 
121 which are positioned between the first and second actuators 4, 5, 
forming an obtuse angle. When the fluid flows from the main channel 121 
into the third subchannel 24, the dead volume is the short channel 25 
connecting the main channel 121 to the second actuator 5, the main channel 
front end portions 121a, 121b positioned between the first and second 
actuators 4, 5, and an intermediate portion 121c of the main channel 121 
positioned between the second and third actuators 5, 6. 
FIGS. 13 and 14 show a fluid control device 140 comprises two 
shutoff-opening devices 101. The device 140 shown in FIG. 13 is 
characterized in that unlike the fluid control device 10 shown in FIG. 3, 
the device 140 has no lower channel blocks 12 and therefore none of the 
device installing screws 14 horizontally driven through the blocks 12. 
Each channel block 11 joined to a massflow controller 2 has a channel 11a, 
which has a lower opening and is held in communication with the downward 
channel 122 by a pipe fitting 123 below the valve main body 103. 
In this way, the space under the valve main body 103 is used for piping not 
only for the first, second and third subchannels 32, 23, 24 but also for 
the main channel 121, whereby the devices, such as the massflow controller 
2 and shutoff-opening devices 101, which are mounted on the upper side of 
a base plate 29 are completely separated from the piping means, such as 
channel blocks 15, 16, 35, fittings 28, 36 and pipe 27, which are-arranged 
under the plate 29. If the massflow controller 2 of the fluid control 
device 140 malfunctions, the controller 2 is removable upward for 
replacement by removing the controller installing screws 13. Further if 
the shutoff-opening device 101 fails, the device 101 can be removed upward 
for replacement by removing the piping installing screws 17 and the piping 
installing screws 17. The piping portion can then be in a flat arrangement 
under the valve main body, compacting the control apparatus in its 
entirety and assuring the component devices and the piping means of 
greatly facilitated maintenance. 
FIGS. 15 and 16 show a sixth embodiment of shutoff-opening device of the 
invention. This shutoff-opening device 131 is similar to the 
shutoff-opening device 101 of fifth embodiment shown in FIGS. 11 and 12 in 
that the main channel 121 has no opening in a rear end face 133c but 
communicates with an opening formed in the lower surface of a valve main 
body 133 via a downward channel 132 formed in the body 133. The 
shutoff-opening device 131 differs from the device 101 in that the 
downward channel 132 extends from an intermediate portion of the main 
channel 121 (between the second and third actuators 5, 6) to the opening 
in the lower surface of the valve main body 133 through a blocklike 
extension 34 of the body 133. The shutoff-opening device 131 provides a 
fluid control device, which has the same feature as the fluid control 
device 140 shown in FIGS. 13 and 14. 
Incidentally, shutoff-opening devices 1, 31, 41, 51, 101, 131 may of course 
be attached to devices other than the massflow controller 2, and are of 
course usable for passing liquids instead of gases.