FR2520473A1 - SAFETY VALVE AND CONTROL DEVICE THEREOF - Google Patents

Abstract

SHUTTER SAFETY VALVE VALVE, CHARACTERIZED IN THAT IT INCLUDES A BODY 21 THROUGH A PASSAGE 22 FOR THE CURRENT AND A SHUTTER 23 THAT CAN PERFORM A BACK-AND-BACK MOVEMENT IN THE INTERIOR BETWEEN OPENING POSITIONS AND FOR CLOSING THE PASSAGE, A CONTROL DEVICE 25 INCLUDING MEANS FOR ELASTICALLY SOLICITING THE SHUTTER FROM ITS FIRST POSITION IN WHICH IT CAN BE TAKEN WHEN A SEVERAL CONTROLLED CONDITIONS TOWARDS ITS OTHER POSITION WHEN ONE OF THE SAID CONDITIONS COME ON. MISSING, MEANS INCLUDING A HANDWHEEL 41 MOUNTED ON THE CONTROL DEVICE TO MOVE THE SHUTTER TO THE SAID FIRST POSITION, AND MEANS RESPONDING AUTOMATICALLY TO A CONTROL SIGNAL TO MAKE THE HANDWHEEL UNABLE TO MOVE THE SHUTTER TOWARDS THE SHUTTER FIRST POSITION WHEN THE SAID CHECKED CONDITION IS REESTORED.

Description

Safety valve and valve

control device.

  The present invention relates generally to gate valves or safety shut-off valves and their control devices, the shutter of which is moved to a first position when it is subjected to one or more controlled conditions, such as a level of predetermined fluid pressure, and which can be resiliently biased towards its other position when this failure occurs

  condition More particularly, it concerns perfec-

  operations brought to safety gate valves and to

  their control devices, of the type in which the shutter

  tor can be moved to said first position by means

a hand-operated steering wheel.

  According to a type of safety valve to which the present invention applies particularly, the shutter is normally held in its first position by means of the control fluid which acts on piston means arranged in the control device for moving a rod connected to the shutter in the desired direction The source of the control fluid, whether pneumatic or hydraulic, may consist of fluid contained in the pipe which is controlled by the valve, a fluid which is supplied by the

  control device in response to a predetermined condition

  born from the fluid in the pipe, or alternatively a

  fluid which is independent of the fluid which is in the pipe.

  In any case, the valve "switches" when the pressure of the control fluid falls below the predetermined level due to an anomaly which may be, for example, a leak in the pipe. In valves of the latter type, the rod is of the lifting type, which can

  be connected to a handwheel for manual movement of the shutter

  towards one or other of its positions For example, in the case of a gate valve designed to close in

  the case where the pressure prevailing in the pipe falls

  below a certain level, the flywheel may be necessary to return the valve to its open position and thus bring the system back to a condition in which the control device will be sensitive to the control pressure. Furthermore, the connection of the flywheel makes it possible to manually close or open the valve in case the mechanism which is

  pressure sensitive is faulty.

  If the handwheel is mounted on the valve stem, as is the case with a valve of this type, so that it is possible to have priority over the mechanism which is sensitive to the control pressure when the valve is not

  not qualified to be considered a safety valve

  rity or as a valve that closes in the event of failure according to standards recognized by API (American Petroleum Institute) In order for valves of this type to be qualified according to these standards, the practice has been to simply provide a means on the rod on which we can

  fix a steering wheel, if necessary Natural-

  Lement, this provision is subject to considerable human errors, such as the absence or improper assembly of the steering wheel, the time and application that are necessary to fix the steering wheel, etc. In addition, it is necessary that the rod to which the handwheel must be fixed in the form of an extension capable of being 'housed' above the bonnet, which increases the space required above the valve by a distance at least equal to the travel of the shutter when it moves

between its alternate positions.

  An essential object of the present invention is therefore to provide a valve and a control device of the type described, the flywheel of which is mounted on the cover of the control device, but which nevertheless qualifies as a safety valve because the steering wheel cannot have priority over the safety system to return the shutter to its other position following a switching and return of the

  system at its controlled condition.

  A more specific object is to provide a tap-

  valve and a control device of this type requiring practically no more space or headroom than the valves and control devices of the prior art of the

type described occupied.

  Yet another object is to provide a gate valve and a control device whose handwheel can be turned

  with minimal effort; and more particularly of propo-

  ser a valve and a control device of this type which can be actuated manually without the assistance of an auxiliary force. There are cases where it is necessary for the valve to switch, and thus it closes or opens, as the case may be, almost instantaneously when there is a fire or when the environment is at a high temperature. be desirable in addition to the ability of the valve to switch due to the appearance of one or more anomalies such as a pressure condition in the pipe, or the like Another object of the invention is therefore to provide a safety gate valve and a control device whose flywheel is rendered inoperative to bring the shutter to its original position when a temperature condition

  predetermined environment of this type manifests itself.

  There are also cases where personnel at the operating site in locations remote from the valve need to know whether or not it has been returned to its controlled position, following switching, and whether for example it is held in this position in response to

  fluid control pressure Another object of the

  It is therefore important to offer a gate valve and a device

  control device of the type described above, the constitut-

  tion is such that it automatically indicates to a person

  located at a distance the position in which the object is

turator.

  Valves of this type with pneumatic control fluid pressure require considerably more pressure sensitive area than when

  these are valves with a hydraulic control fluid.

  Thus, valve control devices or the like may differ widely, depending on the nature of the control fluid, so it can be costly for a manufacturer -z 1

  to offer an Align "of such safety valves

  nant a large number of interchangeable parts This is why yet another object of the invention is to provide a gate valve and a control device of the type described, whose mechanism which is sensitive to pressure can be made sensitive either a pneumatic control fluid either

  to a hydraulic control fluid with a minimum of change

changes or modifications.

  The invention will now be described in more detail and without limitation, with reference to the accompanying drawings in which the same reference numerals designate the

same parts.

  In the drawings: FIG. 1 is a side view of an embodiment of the safety valve produced according to the invention, where the pressure of the control fluid is pneumatic, the left side of the valve being shown in elevation and the right side in vertical section to illustrate the shutter when it is moved to its upper closed position after removal of the pressure of the control fluid at which the

  means used to move the rod is sensitive; -

  Figure 2 is a vertical sectional view on a larger scale of the valve control device of Figure 1, the rod is raised following the closing of the shutter, and the flywheel lowered to come into engagement with the nut and manually rotate the rod, operation by which the valve can be returned to its open position by rotation of the handwheel, and also showing the flag of

  signaling turned to a raised position for information

  tell the lowering of the steering wheel; Figure 3 is a vertical sectional view of one side of the control device of Figures 1 and 2, similar to Figure 2, but when the pressure control fluid has

  been sent to the pressure chamber of the compressor

  command to lift the flywheel from the nut and release it, and keep the rod in its lowered position to keep the valve open, and thus bring the system back to its condition which is sensitive to the control pressure, and also showing

2520-473

  the flag signaled by the uprising of the

  steering wheel to allow it to turn to a lowered position

  which indicates that the steering wheel has been raised;

  Fig 4 is a horizontal sectional view of the end

  upper tee of the valve of FIG. 1, along line 4-4 thereof;

  Figure 5 is a sectional view of the control device

  de, looking down from line 5-5 of Figure 3; Figure 6 is another sectional view of the control device, looking upwards from line 6-6

in Figure 3.

  Figure 7 is a vertical sectional view of part of the control device, along line 7-7 of Figure 3, to show the lower end of the pawl raised from its rotary contact with the nut; Figure 8 is another sectional view of the device of Figures 1 to 7, selor Lqigne 8-8 of Figure 7, to show the brake pads supported by the nut and intended to come into contact with the cover to delay the upward movement of the rod when the steering wheel is raised to the released position of Figure 3;

  FIG. 9 is another view in vertical section of

  the upper end of the control device of FIGS. 1 to 7, to show the mechanism for lifting the flywheel from its engaged position relative to the nut, in response to predetermined environmental temperature conditions; Figure 10 is another view of the upper end of the control device of Figures 1 to 7, partially broken away to show the mechanism shown in Figure 9 from its left side; Figure 11 is a view of the upper end of this control device, along line 11-11 of Figure 9; FIG. 12 is a side view of another embodiment of the safety valve constructed according to the present invention, in which the control fluid is hydraulic, its right side and the upper end of its left side being shown in chopped off; and FIG. 13 is a side view of another embodiment of the present invention, where the shutter is automatically brought to its switching or non-operating position when the steering wheel is raised in response to the failure of a control fluid, the right side and the upper end of the left side of this embodiment being shown essentially in section, as in the case

in Figure 12.

  Referring now to the drawings described above, the valve 20 shown in FIG. 1 comprises a valve body 21 crossed by a passage 22 intended for the current and comprising flanges on its opposite sides to allow the valve to be connected to a pipeline so that its passage is in alignment with the axis of the pipeline A shutter 23 is mounted so as to effect a vertical reciprocating movement inside the cavity of the body of the valve and it comprises an opening 24 which passes through it and which is arranged above the passage of the current in the closed position shown in FIG. 1, and which is in alignment

  with passage into the open position (not shown).

  A control device 25 intended to move the shutter

  between its open and closed positions includes a

  cover 26 able to be mounted on the valve body and

  taking a lower end wall 27 intended to close the upper end of the body cavity when the cover

  is mounted on it A rod 28 is mounted so as to effect

  kill a back-and-forth movement inside the cover 26 and it comprises a lower end which sealingly passes through a hole 29 made in the end wall 27 of the cover in order to establish a removable connection with the end upper shutter As shown, this connection includes a "T" at the lower end of the rod 28 which

  fits inside a conveniently shaped slot

  located at the upper end of the shutter.

  -35 The cover 26 comprises a cylindrical housing 30 comprising

  as an external annular part 30 A which depends thereon, and which is provided with a thread 31-on its internal wall for the connection with the thread provided around a projecting part of the valve body in order to connect the housing in the valve body A flange or cheek facing inward and provided at the upper end of the part 30 A of the housing bears against a shoulder facing upwards of the end wall 27 of the cover to maintain the wall pressed tightly against the upper end of the collar of the upper end of the valve body when the housing 30 is there

connected by screwing.

  A cheek or disc 33 is integral with the rod 28 of

  so you can back and forth with it

  comes into the housing, and it is biased towards its upper position in which a shoulder 28 C of the rod comes into engagement with a shoulder provided on the

  wall 27, below hole 29, by means of a helical spring

  coldal 35 which exerts its action between the disc and the extremi-

  lower tee of part 30 A of the housing which depends thereon.

  More particularly, in the pneumatic embodiment,

  as the safety valve of Figures 1 to 11, the circumference-

  external rence of the disc is in close proximity to the internal wall of the housing 30 and supports a seal around its periphery so as to produce a sliding seal inside the housing. Thus, the disc 33 serves as a piston,

  which, as will be described later, is able to be requested

  cited downwards by the control fluid in opposition to the upward force due to the spring 35 and to the pressure of the pipe which prevails inside the valve body and which acts on the surface of the rod 28 which can slide in the hole 29 The lower end of the annular part 30 A of the housing which depends thereon is open at 36 to constitute a vent for the housing below the piston. As will be described in detail in the following, an upper extension 39 of the cover, above the housing 30, is closed or sealed so as to constitute with the housing above the disc 33 of the piston a pressure chamber to variable volume for the control fluid A pipe 37 is connected to an opening 38 made in the upper end wall 34 of the housing of the cover in order to offer the possibility of sending the control pressure into this chamber, or of the discharge, and when the valve is used in a system of the type contemplated by the present invention, this control fluid provides sufficient force to overcome that of the spring 35 and the pressure prevailing in the pipe in order to hold the piston and the rod 28

  in their lowered position (figure 3) As indicated above

  demment, when eliminating the control pressure of the pressure chamber, the forces which are due to the spring 35 and the pressure prevailing in the pipe raise the piston and the rod to bring them back to the position of Figure 1 and close the shutter However, when the control fluid is stopped, the spring is capable of closing the shutter even

  in the absence of pressure in the pipe.

  The extension of the cover comprises a tubular body 40 whose diameter is considerably smaller than that

  of the housing 30 of the cover and which has a lower end

  upper which is housed by screwing inside a central opening 34 A made in the upper end wall 34 of the housing The axis of the extension is in alignment with the housing so as to receive the upper end part of the rod in its center As seen best on the

  FIG. 3, a flywheel 41 is rotatably mounted on the former

  upper end of the extension 39 of the housing by means of a shaft 42 which depends on the center of the steering wheel and can rotate inside an opening 43 formed in the upper end of the tubular housing 40 More particularly and as will be indicated below below, the shaft can move back and forth coaxially with the rod 28 between an upper position (FIG. 3) which is released from the rod and a lower position (FIG. 2) in which it is made integral in rotation of the stem The shaft is likely to

  turn and perform a back and forth movement inside

  of an O-ring 44 located inside the opening

  ture 43 so as to sealingly close the upper end of the extension of the housing, and it thus constitutes with the housing above the disc 33 a piston which, with the piston 33, defines the pressure chamber inside the cover and to which the opening 38 of the pipe is connected

control.

  A nut 45 is rotatably mounted inside the extension of the cover below the lower end of the flywheel shaft 42. More particularly, the nut is of the ball type and it includes a ring 45 A at its upper end which is held so that it cannot perform

  an axial movement by a lower bearing provided at the end

  upper tee of a sleeve 46 supported inside the extension of the cover by means of a spring ring 47, and an upper bearing which is retained below a shoulder 48 turned towards the bottom of the diameter part reduced by

  the upper end of the hood extension As shown

  felt in the drawings, the nut 45 also comprises a housing 45 B forming a bearing cage dependent on the ring A, and the upper end part of the rod 28 extends upward passing through the internal bore of the ball nut and enters the lower hollow end of the flywheel shaft 42 As shown, the balls contained in the housing forming the bearing cage are in contact with grooves of corresponding dimensions made in the

  upper end of the rod so that when

  that the nut is turned clockwise (looking down), the rod will be caused to move down and thus lower the shutter towards its

open position.

  As best seen in Figure 5, the upper end of the nut support ring 45 includes

  slots circumferentially spaced below the end

  lower tee of the shaft 42 as clearly seen in FIG. 6, the lower end of the shaft 42 comprises

  circumferentially spaced teeth 47 capable of engaging

  wager inside the slots 46 when the flywheel and thus its shaft are lowered in the position of FIG. 2 so as to secure in rotation the shaft and the nut When the flywheel is raised to release the lower end of its shaft of its connection in rotation with the nut, or to bring it there, a shoulder 48 provided around the shaft comes into engagement with a shoulder 49 turned downwards and provided in the housing below the opening 43 to avoid that

the steering wheel comes off.

  The steering wheel, and therefore its shaft, are held in their upper position by means of stop members 50 'constituted by a ball compressed by a spring and mounted in the extension of the hood, and which can penetrate when the shaft is raised, in a lower annular groove 51

  which surrounds the shaft Another annular groove 52 is formed

  killed around the shaft above the groove 51 so as to receive the ball stop members 50 ′ when the flywheel and the shaft are lowered from their position higher than their

  lower position shown in Figure 2.

  As is well known in this field and due to

  its mechanical efficiency, a ball nut reduces consumption

  power when the steering wheel is lowered

  tighten the rod, by comparison with conventional screw locking devices In fact, the flywheel being lifted from the position of FIG. 2 to the position of FIG. 3 so as to disconnect the shaft from the nut, the force of the spring and the force due to the fluid contained in the pipe and acting on the cross-sectional surface of the rod which passes through the hole 29 would allow the shutter to

  lift from its open position to its closed position.

  However, according to the present invention, when the shaft mounted on the flywheel is lowered to come into rotary engagement with the nut, this nut is held so that it cannot perform a retrograde movement, that is to say in the direction anticlockwise when looking at the nut downwards - by means of a ratchet 50 comprising a

  ratchet tooth 51 at its lower end and mounted internally

  laughing of a bore 52 provided in the upper part of reduced diameter of the extension of the cover (see FIG. 6), so as to effect a vertical movement which brings it into engagement or out of engagement with one of the slots 46 made on the upper side of the nut As shown in FIG. 7, the front side of the ratchet tooth 51 comprises

  a vertical face 51 A, while its rear side is inclined

  born in 51 B so that when the pawl is lowered at the same time as the shaft 42 of the flywheel, and as will be described below, its face 51 A comes into engagement with a

  side of the slot in the nut to avoid movement

  retrograde nut, while its inclined face is free to flow up and over the other side of the slot when the nut is turned clockwise by the flywheel shaft The ratchet is requested

  down to its lower position by a helical spring

  coldal 53 acting between its upper end and the upper wall of the hood extension, and a cheek 54 provided at

  the upper end of the pawl and supported on a shoulder-

  ment 55 turned upwards and provided around the flywheel shaft so that the pawl moves down and up at the same time as the shaft, when the shaft is moved by the flywheel, and when 'it is lowered, it rises and falls when it circulates by snapping on the nut. After rotating the steering wheel clockwise to turn the nut and lower the rod and thus open the valve, you can bring the steering wheel up and release it from the nut. the pawl is also lifted from it, the nut is free to move counterclockwise, and due to the mechanical efficiency of the ball nut S, the force due to the spring helical 35 as well as at the pressure prevailing in the pipe and which acts on the rod 28 causes the rod to be raised and the nut to be rotated in the opposite direction so as to raise the shutter towards its closed position Braking shoes 56 are mounted inside an annular groove 57 formed around the nut support ring in order to come into frictional engagement against the internal wall of the extension of the cover, as shown in part 4 in FIG. 8, in view of delay counterclockwise rotation of the steering wheel when the rod is raised, and thus reduce the impact of the 28 C shoulder of the rod against the shoulder of the

  wall 27 of the cover located below the hole 29.

  The extension of the shaft 42 passes tightly inside the O-ring 44 of the extension of the hood housing and determines a piston which is urged upward to disengage the shaft from the nut when control fluid is sent to the pressure chamber of the cover For example, and reference being made to FIG. 2, when the rod lifts and closes the valve, which can happen due to the withdrawal of the control fluid, the system can be reduced to a condition which is sensitive to the control fluid by sending the control fluid into the pressure chamber, which moves the piston disc 33 downwards and returns the valve to its open position At the same time, the control fluid acts on the surface forming the piston of the shaft 42 so as to lift the shaft and the flywheel, and thus release its

  teeth and ratchet of the nut As a result, as long

  as long as the control fluid remains in the pressure chamber of the housing, the flywheel is positively held out of rotation engagement with the nut, which avoids

  Unintentional manual steering wheel maneuvers More

  lly, the flywheel remains in its upper position, even after removal of the control fluid, the valve being thereby in the closed position, until it is manually pushed down into its position in which it

comes in engagement with the hole.

  The rod 28 is preferably formed by ends

  upper and lower tees 28 A and 28 B which can be deployed and retracted respectively As shown, the upper end is connected by screwing to the nut, and the lower end is fixed to the disc 33 of the piston and passes tightly through the hole 29 to be connected to

  the shutter More particularly, the upper ends

  re and lower of the rod are made integral one

  with the other in rotation by means of a groove 57 constituted

  killed on the lower part of the upper end of the rod and received inside a hollow upper part of the lower end 28 B, and a lug 58 on the upper end, of the lower end 28 B of the rod is

  intended to slide vertically inside the rod-

  lure 57 As shown in Figure 2, when the ends

$ 252,047

  upper and lower groove move to the retracted position, the pin 58 comes out of the groove 57, and the upper and lower ends of the rod are maintained in mutual engagement of rotation by means of a cleat 59 provided at the end upper and which moves in a slot 60 formed in the lower end of the rod Thus and as shown, the upper end of the rod is constituted by a relatively large upper part and comprising the cleat 59 formed on it, and a part relatively small lower comprising the groove 57 formed thereon Consequently, when the upper and lower ends of the rod are in their fully retracted position, the torque is transmitted directly from the larger upper part to the lower end, rather 6 t than by the smaller bottom part in which

is formed the groove 57.

  As will be understood, this two-part rod allows the lower end of the rod to lift and

  lower with piston 33 to raise and lower the shutter

  rator without turning the nut, and thus eliminates unnecessary wear of the nut Even if the upper end of the rod is partially lowered inside the nut, from the position of Figure 2 to that of the Figure 3, this rod in two parts reduces at least to some extent the need to rotate the nut due to the fact that the lower end of the rod is raised over its full stroke to

  raise the shutter from its open position to its posi-

tion closed.

  The disc 33 of the piston is of special constitution to compensate for any eccentricity between the axis of the rod and the internal wall of the cylinder contained in the cover in which the piston can slide in leaktight manner Thus, the disc comprises an internal disc 33 A supported by the lower end 28 B of the rod, and an external disc 33 B which carries an O-ring 33 C contained in a groove formed around its external circumference to slide in leaktight manner inside the cylinder More particularly, the external disc has an internal circumference slightly larger than the external circumference of the internal disc so as to overlap the latter and allow a limited radial sliding of the external disc relative to the internal disc The internal diameter of the internal disc is sealed against the lower end of the rod by means of an O-ring 61 supported by the rod, and the internal and external discs are sealed relative to the aut re by means of an O-ring 62 mounted inside a groove formed in the upper face of the internal disc 33, to form a sliding seal with respect to an opposite lower face and overlapping the external disc 33 B The disc internal 33 is kept applied against a shoulder 63 formed around the lower end of the rod, and the external disc 33 B is kept applied down on the disc

  internal 33 A by means of a nut 64 which is screwed onto the end

  upper half of the lower end of the rod The nut 64 naturally has dimensions, relative to the rod, only sufficient to retain the cheek of the piston on the rod, without interfering with the radial movement of the disc

  the outer cheek of the piston in relation to its inter-disc

  born. Furthermore, a signaling flag 65 is mounted on the cover of the control device so as to pivot from an external position and raised relative to the cover which indicates that the flywheel has been lowered and is integral in rotation with the nut, and an internal and lowered position along the side of the extension of the hood, indicated in dashed lines in FIGS. 1 and 3, indicating that the flywheel is raised and is not integral in rotation with the nut. Thus, the signaling flag is supported. at the outer end of the arm 66 which is pivotally connected to a member 67 extending

  upwards from the upper end of the extension

  housing, on one of its sides More particular-

  the inner end of the arm is pivotally connected

  aunt to the member 67 by means of an axis 68 which allows it to switch from a substantially horizontal position in which it raises the signaling flag 65 towards its position indicating that the steering wheel is lowered, towards a hanging position in which it lowers the flag to indicate that the steering wheel is no longer rotational

of the nut.

  As will be understood, the arm and flag of signa-

  lization are normally in the lowered position However, they are brought to their deployed positions outwardly by means of a finger 69 extending from the shaft 66 at a right angle to this arm 66, aq below d '' a mounting ring 70 in the center of the steering wheel and which is fixed so

  removable above the upper end of the rod.

  Thus, when the steering wheel is lowered, the lower end of the mounting ring 70 comes into engagement with the finger 69 to cause it to tilt downward to a position in which the arm 66 is tilted outward towards its

  substantially horizontal position The signaling flag

  tion is held in its outwardly deployed position by engagement of the outer wall of the mounting ring-70 with the inner side of the finger 69 when it has been pivoted towards

  bottom, as shown most clearly in Figure 2.

  The means by which the steering wheel is automatically moved

  towards its upper position when a temperature

  mined and high the environment reigns around the valve is shown in Figures 9 to 11, and it includes a rod 71 which can perform a back and forth movement inside a cylindrical opening 72 formed in

  the upper end of the housing extension,

  below the mounting ring 70 and the flywheel More particularly

  lier, the larger upper end of the rod 71 slides while being guided inside the opening 72 between the lower position shown in Figures 9 and 10

  and an upper position in which the upper end

  stem has out of opening 72 to come into engagement

  ment with the mounting ring 70 of the steering wheel and lift it to its upper position Thus, the rod is urged elastically towards its upper position by means of a helical spring 73 mounted around its lower end of reduced diameter and acting between its upper end of large diameter and the lower end of

opening 72.

  The rod is held in its retracted position in FIGS. 9 and 10 by means of a thin rod 64, constituted by a metal wire, which is removably mounted through the opening 72 and so as to be applied to the larger upper end of the rod 71 One end 75 of the thin rod is received in a hole provided on one side of a slot 76 made in the extension of the housing so as to form a pivot around which the thin rod can pivot

  counterclockwise, as shown

  qué by the arrow of Figure 10, to release the rod 71 in

  view of its upward movement to raise the steering wheel.

  The opposite end of the thin rod is normally now

  naked by means of an element 77 fusible with heat and supported by a console 78 fixed in a recess 79 cut in a

  side of the housing extension As shown, the end

  upper part of the retaining element 77 is disposed above

  above the free end of the thin rod 74 so as to keep this thin rod substantially horizontal until the element 77 melts in the presence of a high temperature of the environment Naturally, when this occurs and when the flywheel is lifted and disconnects from the nut, the nut is free to rotate so that the rod can be lifted by the spring 35 and by the force of the

  fluid contained in the pipe, to allow the obtura-

  tor to fall into its closed position.

  The embodiment of the safety valve represents

  tée in Figure 12 is substantially identical to that described above, except for the constitution of the mechanism which is sensitive to the supply of the control fluid, to normally maintain the valve in its open position, and then for l '' allow to close when the control fluid is no longer sent in the pipe Thus and reference being made to Figure 12, a disc 80 is fixed to the lower end 28 B of the rod by means of a nut

  81, and is biased upwards by a helical spring.

  dal 35 mounted inside the cover, as described in reference

  this in the pneumatic embodiment However, in this hydraulic embodiment, the disc and therefore the rod are biased downward by a series of pistons 82 which can perform reciprocating movements inside cylinders formed inside of tabular bodies 83 mounted on the upper wall 34 of the cover housing, being circumferentially separated around the extension of the housing Thus, the disc 80 ends at a short distance from the internal wall of the cover housing so as to avoid a

  contact with it when it makes its downward movement

  back and forth inside the cover housing in response to the sending of the control fluid in the cylinders contained inside the tubular bodies 83, and their withdrawal from

these cylinders.

  The upper end of each of the pistons 82 carries an O-ring 84 which surrounds it for its sealed sliding inside its cylinder, and it has a length such that its lower end is applied to the upper side of the disc 80 and moves this disc to its lowest position to retain the valve in the open position in response to the sending of the control fluid The fluid

  is sent to each of the cylinders via the

  medial of a common pipe 85, and evacuated from these cylinders by this same pipe, which comes from a source of hydraulic fluid and includes bypass lines which reach the openings 86 made in the ends

upper cylinders.

  Thus, although the shaft 42 of the flywheel is shown to be received in a sealed manner in the opening 43 at the upper end of the extension of the housing, this is provided in the first place to prevent dirt from entering the nut. balls and its associated parts In other words, it is not necessary to maintain a pressure inside a chamber formed inside the housing of the cover On the other hand, the means by which the flywheel is automatically moved from its lower position to its upper position in response to the sending of the control fluid to the cylinders of the pistons 82 is constituted by one or more pistons 90 which can slide inside cylinders 91 formed at the upper end of the extension of the housing, below the flywheel mounting ring Rods 92 mounted on these pistons sealingly pass through bearings 93 so as to come into contact with the lower side of the flywheel mounting ring As will be understood on examination of FIG. 12, when the piston 90 is in its lower position, the rod 92 is in a low position in which it does not interfere with the downward movement of the mounting ring and of the flywheel on the other hand, when there is an upward movement of the piston 90 to the position shown in FIG. 12, the upper end of the rod 92 comes into engagement with the mounting ring and forces the flywheel to its raised position. control fluid from a common source such as that which feeds the cylinders 83 is sent to the lower end of the piston 90 by means of a line 94 bypassing the line 85 and reaches the lower end of the cylinder 91 Consequently, and as described above, when the control fluid is sent to each of the pistons 82 to maintain the shutter in its open position, the flywheel is automatically raised to its upper position by releasing the shaft 42

  of the nut by means of which the rod is actuated manually.

  It will be understood that the valve control device of Figure 12 is also identical to that of Figures 1 to II Thus, as shown in Figure 12, an arm

  can be mounted on the housing extension to support

  ter a signaling flag 65 Likewise and although this is not shown in the figure, it will be understood that the valve control device comprises a pawl whose constitution is the same as that of the pawl 50 described with reference to the mode of pneumatic embodiment of FIGS. 1 to 11, and which fulfills the same function More naturally, it can be provided with means such as that shown in FIG. 9, to cause the shutter to close in the event of

  failure in response to a predefined temperature condition

completed environment.

  The safety gate valve and the control device of FIG. 13 are similar in construction to each of the embodiments of FIGS. 1 to 11 and of the

  figure 12, insofar as the constitution and function-

  The flywheel, the nut and the stem are retained. Similarly, it is similar to that of FIG. 12 in that a disc 80 is fixed to the disc 28 and is biased upwards by a spring 35, as well as for other aspects which

  will appear on examining the drawings In this valve, the ob-

  the impeller is kept in its open position controlled by lowering the flywheel in order to connect it in a rotary manner with the rod, in response to the pressure of the control fluid,

  and the subsequent rotation of the flywheel to lower the rod.

  However, when the steering wheel is raised due to the failure of the control fluid, as shown in FIG. 13, the rod is free to lift due to the stress applied to it by the spring 35 and the pressure prevailing in driving, domme in the case of

other embodiments.

  As shown, the control fluid is sent through a line 100 into a cylinder 101 formed at the upper end of the extension of the cover below the flywheel mounting ring, and a piston 102 is mounted so as to slide from sealingly inside the cylinder between the lower position when the control fluid is sent through the line 100, and an upper position which is shown, when it is subjected to the stress of a helical spring 103 - located above - below, when we stop sending the control fluid At this moment naturally,

  the rod and thereby the shutter are lifted from the posi-

  tion shown in Figure 13 due to solicitation

  applied by the spring 35 and by the fluid in the line

  te Thus, as in the case of the rod 92 described with reference to the valve of FIG. 12, a rod 104 extending upwards from the piston and passing through a packing or sealing nut 105 to the the upper end of the cylinder 101 has a length sufficient to allow the flywheel to be lowered into the position in which it comes into rotational engagement with the nut, when the piston is lowered, but to come into engagement and raise the flywheel mounting ring to its upper position when the piston is raised when the control pressure fails. Naturally, and as mentioned in connection with FIG. 12, the valve and the control device of FIG. 13 can also include means, shown in

  figure 9, to raise the steering wheel in response to a temperature

  predetermined environment, as well as a signal flag to visually indicate the position of the

steering wheel.

Claims (17)

R E V E N D I C A T I O N S   1 Safety shut-off valve, characterized in that it comprises a body (21) through which   a passage (22) for the current and a shutter (23) for   vant perform a movement back and forth inside between the opening and closing positions of the passage, a control device (25) comprising means for   apply elastic pressure to the shutter from its first   re position in which it can be brought when reign   one or more conditions checked towards its other posi-   tion when one of the said conditions is missing,   means include a hand wheel (41) mounted on the device   control device to move the shutter to said first position, and means automatically responding to   a control signal to render said hand wheel disabled   ble to move the shutter to said first position   when said controlled condition is restored.   2 Safety gate valve with shutter, characterized in that it comprises a body (21) crossed by a passage (22) for the current and a shutter (23) capable of performing a back-and-forth movement with the interior between   opening and closing positions of the passage, a   control positive (25) comprising a rod (28) connected to the shutter and mounted so as to effect a movement of   back and forth in opposite directions to move the object   between said positions, means (35) for urging   resiliently cite the rod in one direction in order to move the shutter from a position to which it can be brought when one or more conditions prevail   controlled at its other position when one of said   ditions is lacking, means comprising a hand wheel (41) mounted on the control device for moving   the rod in the opposite direction so as to move the shutter   towards its first position, and means responding automatically   matically to a control signal to render said handwheel incapable of moving the rod in said opposite direction when one of said controlled contours is restored. 3 Safety shut-off valve, comprising a body (21) crossed by a passage (22) for   the current and a shutter (23) capable of effecting a movement   ment of back and forth inside between opening and closing positions of the passage, a control device (25) comprising a rod (28) connected to the shutter and mounted so as to effect a back and forth movement in opposite directions to move the shutter between said   positions, piston means (33) which react to the feed   ment of a control fluid which is sent to them to urge the rod in a first direction and move the shutter to its first position and maintain it in this position as long as the control fluid is maintained at a predetermined pressure level of the means   (35) to elastically urge the rod in the other direction   rection to move the shutter to its other position   tion in the case where the control fluid is not thus maintained, means comprising a hand wheel (41) mounted   on the control device to move the rod in the-   said first direction and move the shutter to its other position, and means automatically responding to a control signal to render said hand wheel incapable   moving said rod in said first direction.   4 Safety gate valve according to one   claims 1 to 3, characterized in that the signal   command automatically responds to the reinstatement of said condition checked.   Safety gate valve according to one   claims 1 to 3, characterized in that the signal   command automatically responds to the failure of said condition checked.   6 Safety gate valve according to one   of claims 1 to 3, characterized in that said con-   controlled dition is a predetermined pressure condition fluid.   7 Safety gate valve according to one   claims 1 to 3, characterized in that the condition   controlled is a predetermined environmental temperature condition. 8 Safety gate valve with shutter, characterized in that it comprises a body through which a current flow passes and a shutter which can move back and forth inside between open and closed positions. closing the passage, a control device comprising a rod connected to the shutter and mounted so as to move back and forth in opposite directions in order to move the shutter between said positions, means for elastically biasing the rod in one direction to move the shutter from   a first position to which it can be brought when   that one or more controlled conditions prevail towards its position when one of said conditions comes to be missed, means comprising a hand wheel mounted on the control device and intended to be maneuvered towards a position in which it has the capacity to move the rod in   the other direction so as to move the shutter towards the   said first position, and another position in which the handwheel is unable to move said rod in   said other direction, and means responding automatically-   lie to a control signal to move said handwheel from its first position to its other position when   said controlled condition is restored -   9 Safety gate valve as per   vendication 8, characterized in that it comprises means which automatically respond to the operation of the steering wheel in order to visually indicate the position in which it is located.   Safety gate valve according to re-   vendication 8, characterized in that it comprises means for moving said handwheel automatically to its other position in response to a predetermined temperature of the environment.   11 Safety shut-off valve, characterized in that it comprises a body through which a current flow passes and a shutter which can move back and forth between positions   opening and closing of the passage, a device for   mande comprising a rod connected to the shutter and mounted   back and forth in di-   opposite rections for moving the shutter between said * positions, means for elastically urging the rod in a first direction in order to move the shutter   from a first position to which it can be moved   born when one or more controlled conditions prevail towards its other position when one of said conditions runs out, a handwheel mounted on the control device and which can be turned manually from the outside, means which can be moved between a first position which connects the handwheel and the rod in order to move the rod in the other direction eniPonse to the rotation of the handwheel, and a second position which disconnects in rotation the rod and the handwheel so that the handwheel by hand no longer has the possibility of moving the rod in said other direction, and means automatically responding to   a control signal for moving said connection means   nexion and disconnection from their first to their second   position when said controlled condition is restored.   12. Safety gate valve with shutter according to claim 11, characterized in that the means for connecting and disconnecting the rod and the handwheel comprise a nut rotatably mounted and connected by screwing to the rod, and means on the hand wheel which   can come by rotation in engagement or out of engagement-   with the nut in response to the operation of the handwheel.   13 Safety valve prefection-   born according to claim 12, characterized in that the nut is a ball nut, and in that a means can be brought   in engagement with the ball nut to prevent rotation   tion in a direction that moves the rod in an op-   posed, when the connection and disconnection means are moved with the nut, and out of engagement with said nut to allow this rotation, when the connection and disconnection means are moved and when they are released   of their connection in rotation with the nut.   14 Improved safety gate valve according to claim 12, characterized in that the handwheel comprises a shaft mounted inside the cover for its rotation and its reciprocating movement between internal and external positions, and in that said shaft comprises means fixed on it to come into rotational engagement with the nut when the handwheel is brought   in one of said internal and external positions.   15 Safety shut-off valve, characterized in that it comprises a body crossed by a passage for the current and a shutter capable of effecting   a back and forth movement inside between posi-   the opening and closing of the passage, a control device comprising a rod connected to the shutter and mounted so as to move back and forth in opposite directions in order to move the shutter between said positions , piston means sensitive to the supply of the control fluid which is sent to them to urge the rod in a first direction so   move the shutter to a first position and hold it   hold in this position as long as the control fluid is maintained at a predetermined pressure level of the means for elastically biasing the rod in the other direction in order to move the shutter to its other position in the case where the control fluid is not   thus maintained, means comprising a hand wheel   tee on the operating member to move the rod in the first direction, means which can be moved between a first position which connects the handwheel and the rod in order to move the rod in said first direction, in response to rotation of the hand wheel, and a second position which disconnects in rotation the rod and the hand wheel so that the hand wheel no longer has the possibility of moving the rod in said first direction, and additional piston means which respond automatically to the supply of the control fluid of said first-mentioned piston means for moving said means   connection and disconnection to their second position.   16 Improved safety gate valve according to claim 15, characterized in that the means which comprise the piston means comprise a plurality of cylinders arranged around the rod, and a piston capable of   slide tightly inside each cylinder.   17 Operating device according to the claim   tion 15, characterized in that the piston means comprise   have a cylinder in the hood and a piston on the rod which   can slide tightly in the cylinder.   18 Operating device for gate valve   with shutter, characterized in that it comprises a body   carrying a rod mounted therein for back and forth movement in opposite directions, a   nut connected to the rod, means mounted on the rod internally   body to rotate, without movement   axial, a handwheel comprising an internally mounted shaft   body for rotation and movement   vement back and forth between internal and external positions in axial alignment with the rod, and-means on the shaft which can come into rotational engagement with means provided on the nut, when moving the tree towards a first   position, so that the rod can be turned by means of the   hand lantern in a first direction, and to disengage it in rotation when the shaft is moved to its other position,   so that the handwheel cannot move the rod.   19 valve shutter valve actuating member according to claim 18, characterized in that the nut is a ball nut, and in that means are   mounted inside the cover to prevent rotation of the   ball nut in opposite direction when the means provided on the shaft come into rotation engagement with means   provided on the nut, but allow this rotation when the-   said means provided on the shaft are free from rotation of the said means provided on the nut.   Valve shutter operating member according to claim 19, characterized in that it comprises braking means on the nut which come into frictional engagement with the body in order to delay the   rotation of the nut in said opposite direction.   21 valve shutter valve actuating member according to claim 19, characterized in that the means provided on the nut are constituted by slots formed in this nut, the means at the internal end of the shaft include tenons which can be brought into rotational engagement and out of rotational engagement with the slots, and the means for preventing rotation of the nut   include a pawl mounted to move   back and forth in the body to one side of the tree   between an internal engagement position with a pre-slit   ticked in the nut and an external position which is released therefrom   aged. 22 valve shutter valve actuating member according to claim 21, characterized in that it comprises means resiliently biasing the pawl towards its internal position, and means provided on the shaft to move the pawl with it towards their positions external and to allow the elastic biasing means to move the pawl towards its internal position when the shaft   moves to its internal position.   23 Valve gate actuator.   shutter according to claim 18, characterized in that it   includes means on the body to move automatically-   lie the shaft towards its nut release position in   response to a predetermined environmental temperature.   24 valve shutter operating member according to claim 18, characterized in that   includes means in the hood for moving automatically-   the handwheel shaft to its nut release position in response to a signal from (command determined by fluid pressure.