FR2624245A1 - RELIEF VALVE; COMPRISING A REDUCED VALVE CASING AND HAVING ADDITIONAL RADIATION BAND CHANNEL ADJUSTMENT GROUPS - Google Patents

Abstract

a) Throttle valve, comprising a reduced valve housing and having additional groups of radial throttle channels. b) Characterized in that the throttle element 19-29 has at least one additional group of radial throttle channels 14, observing in the longitudinal direction of the throttle member, at least two of the groups of channels throttle 14, 20 are arranged at a distance one behind the other, the closure part 9 has at least one additional slide 31, which is movably arranged to execute a stroke in the longitudinal channel 8, in the region of the additional throttle channel group 14. c) The invention relates to a throttle valve comprising a reduced valve housing and having additional groups of radial throttle channels.

Description

Throttle valve, comprising a crankcase

  Pope reduced and presenting additional groups

  radial throttling channels ".

  The invention contemplates a choke valve

  comprising a valve housing, a throttle element disposed in the valve housing, which has a valve seat, a longitudinal channel and a group of radial throttling channels, a portion

  shutter, which has a drawer located in the

  nal longitudinal, running in the area of the choke channels, and a sealing surface

  cooperating with the valve seat.

  Throttling valves of this type serve

  wind to the control, respectively to the regulation of

  flow rates of fluids with significant pressure differences

  your. Here, depending on each stroke position of the sealing portion, a greater or lesser number of radial throttle channels is released.

  the throttling element for fluid flow.

  This allows a flow control, respectively a very sensitive flow control. To reduce the pressure of the fluid through, it is known (US-PS 14 074) to provide in the throttle channels a more or less abrupt change of direction, consuming energy. For the same purpose, we know by

  example to have in foreign channels

  one or more narrowing,

  with intermediate relaxation rooms.

  The pressure difference determines the name

  the necessary throttling measures in a throttling channel and thereby influences the dimension of the throttle in the radial direction. In the case of known throttle valves, throttling elements of relatively large diameter are

  necessary for very large pressure differences

  bearing. This again requires casings of

  valve of large volume, heavy and expensive.

  The object of the invention is to create a throttling valve of the type indicated at the beginning, for which

  a valve casing of relative volume can be used

  small, even for high pressure differences. This problem is solved in that: the throttling element has at least one additional group of radial throttling channels, observing in the longitudinal direction of the throttling element, at least two of the groups of channels;

  throttles are arranged at a distance one behind

  the other, - the closure part has at least one additional drawer, which is movably arranged to execute a stroke in the longitudinal channel, in the area of the additional throttle channel group, - an inner annular chamber is located in the longitudinal channel, each time between two drawers,

  - at least one outer annular chamber is provided

  therethrough, which surrounds the throttling element in the region of a group of throttle channels, and - the throttle element each has at least one radial passageway between two groups of throttle channels arranged one behind the other, this seen in the longitudinal direction of the throttle element, channel connecting a chamber

  inner ring and an outer annular chamber

  pool. It is arranged at least 2 groups of channels

  strangely, one behind the other, in direct

  longitudinal direction of the throttling element. As a result, the dimensions of the throttle element are relatively small in the radial direction. Despite the significant length of the throttle element, the valve housing is generally constructed with a significantly smaller volume. It is thus lighter

  and a more favorable cost. By means of the drawer

  part of the throttle element, we are

  that the appropriate number of throttling channels is released in each group of throttling channels

  and thus we obtain an irre-

next to the flow of fluid.

  Other benefits and improvements are

  characterized in that: the throttling element

  an additional valve seat in the area of the group of additional throttle channels, the sealing portion has an additional sealing surface in the area of the additional drawer,

  surface cooperating with the additional valve seat

  and the two sealing surfaces of the sealing portion are movable relative to each other so as to perform a limited stroke; a slide of the closing part is provided with a reception bore open towards another drawer, a rod of

  connection emerging in the receiving bore is pre-

  view of the other drawer, stem with a drive

  stroke within the bore of the receiver.

  and in the receiving bore, one of the drawers has a travel stop for the running workout; a spring urging the connecting rod in the direction of the valve closing is disposed in the receiving bore; a balancing piston connected to the first spool, observing in the direction of flow of the fluid passing through, and a chamber of

  pressure receiving the balancing piston, chamber

  connected to the inner annular chamber and whose internal pressure is biasing the balancing piston in the direction of closing the valve; the part

  at the end located on the upper side

  pressing an actuating rod, which has a thicker portion of the shank in the vicinity of the sealing portion and, at a distance from the sealing portion, a thinner stem portion, the actuating rod passes through the chamber pressure, the front surface of the thicker portion of the shank and located at a distance from the sealing portion therein in the pressure chamber, a pressure-tight guideway for the thicker shank portion is disposed at one end of the chamber of

  pressure and a pressure-tight guideway to the pressure

  intended for the thinner part of the shank is

  se at the other end of the pressure chamber; a seat ring disposed between the throttle channel groups of the throttle element, the ring having at its inner edge the valve seat

  intended for the filling part and its outer edge

  a peripheral rear projection, a seal applied to the rear projection, a

  casing wall radially surrounding the seat of

  poppet and the seal, a spacer tube resting at one of its ends on the seal, tube surrounding at one end the throttling element and having throttling channels

  radials, and holding means acting frontally

  on the spacer tube and the other throttling element; the choke channels located in

  the spacer tube and the throttling channels

  in the adjacent part of the throttle element are mutually offset laterally and the throttle spacer tube surrounds the throttle element with a radial gap which is smaller than the free passage channels

  throttle; a base ring placed at the end

  of the throttling element, having on its outer edge a peripheral rear projection, a seal applied to the rear projection, a casing wall radially surrounding the seal and the base ring, wall having a

  axial abutment for the base ring, and a tube of

  extending between the seal and the

  basic water and the seat ring, tube surrounding with

  a radial spacing the section of the foreign element

  tightly packed axially between the two rings; the base ring has at its inner edge the other valve seat for the sealing portion; the parts of the throttling element having a group of throttle channels each consist of a set of sockets plugged into each other

  others, with radial throttling channels.

  In the case of such throttling valves, a radial clearance - even if limited - is inevitable between the shutter part and the throttle element. For this reason,. fluid can flow between the sealing surface of the part

  shutter and valve seat during a lift

  limited clearance of the sealing surface of the sealing part on the valve seat, thus before the longitudinal channel of the throttle element is released to the radial throttling channels placed

  following the valve seat. Flow velocities

  very high appear in the narrow slit

  between the valve seat and the sealing surface

  gap in the shutter part in the case of a very large pressure difference between the channel

  inlet and outlet of the throttling valve.

  These speeds can lead to erosion wear.

  An improvement of the invention is characterized

  in that the throttling element has an additional valve seat in the zone of the additional throttling channel group, the part

  shutter has an additional sealing surface

  in the area of the additional drawer, surface

  this cooperating with the additional valve seat,

  the two sealing surfaces of the closure part

  are movable relative to one another

  to run a limited race.

  It follows - advantageously in the case of throttle valves whose drawers are each upstream of the corresponding valve seat

  - blocking in two points placed one behind the other

  compared to the fluid flow circuit. To open the throttle valve, a single sealing surface of the valve seat is first raised, preferably one located in the direction of flow in the forward direction. The other sealing surface of the sealing part still remains

  in the closed position due to mobility

  lative of the two sealing surfaces. As a result, no fluid flow can be established leading to erosion wear. As soon as a sealing surface of the sealing part is moved away from its seat of

  valve of such value that there is no longer any risk

  than erosion, the other part sealing surface

  shutter is then raised from its seat

  pe. This may for example be the case when the

  flow between the sealing surface of

  part of the flow previously raised and its

  Valve ge is a multiple of the radial clearance between the drawers and the throttle element. The element

  This strangulation thus presents a barrier

  protected against erosion and

  therefore achieving a leakproof safety insulation

  you. Another improvement of the invention is

  characterized in that a drawer of the closure portion

  it is provided with a receiving bore open to another drawer, a connecting rod emerging in the receiving bore is provided on the other drawer,

  rod presenting a race training to the

  of the receiving bore, in the bore of

  In this case, one of the drawers has a travel stop for the stroke drive, a spring biasing the connecting rod in the direction of the closing of

  valve is disposed in the receiving bore.

  We thus obtain embodiments

  particularly simple and safe operation.

  The drawer produces an additional sealing force

  re on the second dam point. In position of

  valve, the spring prevents movement of the

  undesirable effects of the second drawer facing the action

  fluid flow forces.

  Another improvement of the invention is

  characterized in that a balancing piston is re-

  connected to the first slide, observing in the direction of flow of the fluid passing through, that a chamber of

  pressure receives the balancing piston, chamber

  linked to the inner annular chamber and whose internal pressure urges the balancing piston in the direction of closing the valve, thanks to

  what the influence of the pressure prevailing in the room

  The inner annular groove on the actuating force is significantly reduced. The pressure oscillations occurring in the inner annular chamber remain

  without a disadvantageous effect on the movement of

  opening of the throttle valve. This applies in particular to the throttle valves whose actuating rod has a relatively large diameter to reduce the closing force produced

  by the pressure. An abrupt and abrupt race

  of the blocking part is avoided, even if the throttling valve is actuated by an elastic

  drive). Another particular embodiment

  is advantageously characterized in that the filling portion has at its end located

  high pressure side an actuating rod, which pre-

  in the vicinity of the filling part

  Thinner rod portion and, at a distance from the sealing portion, a thinner rod portion, the actuating rod passes through the pressure chamber, the front surface of the rod portion is thicker and

  located at a distance from the closing part is

  on this occasion in the pressure chamber, a pressure-tight guideway through the pressure

  part of thicker rod is disposed at one end

  the pressure chamber tee and a pressure-tight through guide for the thinner rod portion is disposed at the other end of the pressure chamber. According to this, the actuating rod of the

  throttle valve forms the balancing piston.

  Another embodiment of the invention

  tion is characterized in that a seat ring

  between the groups of bottlenecks

  the throttling element, a ring with

  inner hard seat valve seat intended for par-

  shutter and at its outer edge

  peripheral back, a sealing point

  on the rear projection, a casing wall

  radially the valve seat and the gasket, a spacer tube resting on one of the

  its ends on the gasket, tube

  at one end the throttle element and

  sensing radial canals, means

  holding device acting frontally on the eccentric

  With the other throttling element, a reliable peripheral seal of the throttle element in the valve housing is obtained between the two groups of throttle channels. The compression

  seal is limited to a defined value

  denies, because the holding means act simultaneously on the spacer tube and the rigid throttle element. Overloading of the seal is prevented. The spacer tube exerts

  additionally a throttling effect on the fluid passing through

  health. This additional function has a positive effect

  on the volume of construction.

  Another embodiment of the invention

  It is characterized in that the barrier point is protected against large particles of dirt, because the throttle channels in the spacer tube and the throttle channels in the adjacent part of the element are throttled laterally, the spacer tube of the throttle element surrounds the throttle element with a radial gap which is smaller than the free passage of the channels

throttling.

  Because the throttle channels of the spacer tube and the throttle element are fully offset from each other, the annular gap between these two parts forms the narrowest flow section and prevents larger dirt particles

  can arrive at the dam point.

  Another embodiment of the invention

  The invention is characterized in that a reliable axial support and end-side sealing of the throttle element in the valve housing is obtained, that a base ring is arranged at the end of

  the throttling element, having on its outer edge

  rear peripheral protrusion, a sealing point is applied to the rear projection, a housing wall radially surrounds the seal and the base ring, wall having an axial abutment for the ring of base, and that a spacer tube extends between the seal and the base ring and the seat ring, surrounding tube with a radial spacing the section of the element

  throttling tight axially between the two years

  Neaux. Even in this case, the seal is protected against excessive deformation. Moreover, the spacer tube protects the housing wall against

wear by jet effect.

  A particularly advantageous provision

  it is characterized in that the base ring has at its inner edge

  the other valve seat for the sealing part.

  As far as the throttling element is

  made in several parts, it is particularly

  advantageously that the parts of the element

  with a group of foreign channels

  Each of these elements consists of a set of sockets plugged into each other, with radial throttling channels. In the case of a distribution

  corresponding bottlenecks on the perimeter

  the socket, it is possible, with one and the same set of sockets, by rotation of the sockets, also

  good to vary the flow performance through

  that also the characteristic race-flow

  only to adapt it to each need.

  Embodiments of the invention are shown in the drawings, namely: FIG. 1 shows a throttling valve with two drawers fixed relative to one another,

  FIG. 2 shows a view of the choke element

  FIG. 3 shows a throttling valve with two drawers movable in a reciprocally limited manner to execute a stroke; FIG. 4 shows another throttling valve with two drawers movable against each other;

limited to run a race.

  In FIG. 1, a valve casing 1

  an inlet channel 2, an outlet channel 3 and an interior space 4. A multi-stage throttling element is arranged in the interior space

  4, element which is surrounded on a part of the

  5 by a casing wall 5 and which rests at its end on the outlet side on an axial stop 6 of the casing.

  1. A holding element 7 acts on the former

  the inlet side of the throttle element and by means of which the individual parts of the throttle element are held in the position of

planned assembly.

  A movable shutter portion 9 for executing

  a race is located in a long canal

  dinal central 8 and has at its end adjacent the inlet channel, an actuating rod 10 emerging from the valve housing 1. A seal ensures a pressure-tight guideway through the pressure of the actuating rod 10 to the 'outside.

  The element of restraint presented to its ex-

  tremité side output a base ring 12 based on the axial stop 6. A first set of sockets 13 plugged into each other is located above,

  sockets with 14 throttling channels

  diaux located in several planes. A ring of spread

  16 with radial passage channels is

  placed frontally on the sleeves 13, spacer ring having at its inner edge a valve seat 18. If necessary, the ring of

  seat 17 and the spacer ring 16 may be

  grouped into a single part. A second set of sockets 19 plugged into each other is placed on the seat ring 17, sockets having throttling channels 20 located in several planes. Both the seat ring 17 and the base ring 12 are circumferentially provided with a peripheral rear projection 21, 22, in which a seal 23, 24 is located each time. A spacer tube 25 extends between the seat ring

  17 and the seal 23 of the base ring 12.

  This spacer ring, the sealing joint 23, 24 and the two rings 12, 17 are closely enclosed

  radially through the casing wall 5. An annular chamber

  outer ring 26 surrounds the outer sleeve 13 of the first set of bushings and the spacer ring

  16. The outer sleeve 19 of the second sleeve set

  is surrounded by forming an annular slot 27 by a spacer tube 28 which has radial throttling channels 29 and presses with one of its ends on the seal 24 located on the seat ring 17. The holding piece 7 acts on the other end of the spacer tube 28 and at the same time also frontally on the sockets 19. As a result, the sockets 19, the seat ring 17, the ring 16, the sockets 13 and the base ring 12 are rigidly pressed one on the other and

  maintained in their mounting position. Simultaneous-

  the seals 23, 34 are compressed to a value determined by the spacer tubes 25,

  28, so that they radially support

  leak tight on the housing wall 5 and on the ring

  seat 17, respectively on the base ring 12.

  The filling part 9 has two halves

  30, 31 at an axial distance fixed relative to each other. One of the drawers 30 is disposed upstream of the valve seat 18 in the socket 19. It has frontally a sealing surface 32 cooperating with the valve seat 31. The other drawer 31 is disposed in the sleeve 13 The longitudinal channel 8 of the throttling element 12-29 forms between the two

  drawers 30, 31 an inner annular chamber 33.

  The throttle channels 29, 20 of the spacer tube 28 and the bushing 19 are completely offset laterally relative to each other (Fig. 2). The radial slot 27 located between the spacer tube 28 and the sleeve 19 is considerably smaller than the free space of the throttle channels 29. The throttle channels 20 of the sockets 19 are offset relative to those each time neighbors on the socket 19 the value of a portion of their free space (Figure 2). Chokes and intermediate expansion chambers are thus formed on the contact surfaces of the sockets 19. This also applies in the same spirit for the sockets

  13 and their choke channels 14.

  To effect a barrier, the sealing surface 32 of the spool 30 comes into the throttling valve of FIG. 1 bearing on the valve seat 18. At the same time, the spool 30 covers the

  less in the plane next to the seat ring the

  seems to be the throttling channels 20 of the bushing

  19, while the drawer 31 covers at least in the plane adjacent to the base ring 12 all

  throttling channels 14 of the sleeve 13.

  For opening, the sealing surface 32 of the spool 30 is lifted from the valve seat 18. Depending on each stroke position, the drawers 30, 31 moved simultaneously release an adequate number of throttle channels 20, 14, both in the sockets 19 and also in the sockets 13. The

  Fluid first flows through the channels of foreign

  29 located in the spacer tube 28 and undergoes a first throttling therein. He then arrives in

  the annular slot 27, which holds the impurities

  turbulators because of the small width. From there, the fluid continues to flow through the throat channels 20 released by the drawer 30 and undergoes

  additionally a multi-stage throttling.

  The remainder of the flow path leads through the inner annular chamber 33, the passage channels

  and the outer annular chamber 26, in the cases

  throttling 14 sockets 13 released by the

  drawer 31. The fluid is again strangled at several

  floors, and then flows into the channel of

exit 3.

  Several strangulations were obtained

  It is very effective with a throttling element of relatively small diameter. The small diameter of the throttle element makes it possible to obtain a crankcase

  valve with a volume and a mass of

  latively small, of a favorable price. For the case of extreme pressure differences, it is quite possible to dispose in the direction of flow of the throttle element three sets of bushings or

  plus and a corresponding number of drawers on the

shutter.

  The through-flow of the throttling valve according to FIG. 1 can, if necessary, also be carried out in the opposite direction to the

represented meaning.

  The throttling valve of FIG. 3 is largely equivalent in construction to that of FIG. 1. In any case, it is provided in FIG.

  second valve seat 34; it's on the year

12. The drawer 30 has a sealing surface 35. The two drawers 30, 31 of the closure part 9 are each arranged upstream of their valve seat 18, 34 and are, for this reason, movable. relative to each other in a limited way, to execute a race. For this purpose, the front drawer 30 - seen in the direction of the flow - present

  a receiving bore 36 open towards the drawer ar-

  31. The rear spool 31 is provided with a connecting rod 37 which emerges in the receiving bore

  36 and presents a race training.

  30 has in its receiving bore 36 a travel stop 39 for moving the en-

  stroke 38 to the drawer 31. A spring

  40 is disposed in the receiving bore 36, acting

  on the connecting rod 37, in the direction of the

closing the valve.

  In the throttling valve of FIG. 3, the two sealing surfaces 18, 34 of the sealing part 9 press in the closed position on their valve seats 18, 34. On this occasion, axial clearance exists between the running drive 38 and the travel stop 39. During the opening process, the front spool 30 with the sealing surface 32 is first lifted from the valve seat 18. The rear spool 31 is located during this process. subjected to the action of the spring 40 and the pressure in the annular chamber 33, with further the sealing surface 35 on the valve seat 34. At this time, no fluid flow can still be formed at stop point 34, 35. During the subsequent opening process, the travel stop 39 bears on

  the race training 38, so that the sur-

  Sealing face 35 of the rear spool 31 is then also raised from its valve seat 34. In the fluid flow then establishing, the expected flow velocity in the barrier point zone 18, 32 is located at below the value which may result in erosion wear on the

  sealing surface 32 and on the valve seat 18.

  In the continuation of the uprising of the part of ob-

  turation 9, the choke channels 14; 20 located

  in the sockets 13, 19 are released, ie simul-

  in both sets of sockets.

  Due to the mutually delayed opening and closing of the two dam points 18, 32, 34, 35 placed one behind the other in the direction of flow, erosion wear at

  dam is reliably prevented.

  The throttling valve according to Figure 4 differs from that of Figure 3 in that the actuating rod 10 of the sealing portion 9 has in the vicinity of the sealing portion a portion of thicker rod 41 and away from the

  shutter part a thinner part of shank 42.

  There is also a pressure chamber 43

  towards which emerges the actuating rod 10. The former

  the end portion remote from the sealing portion and belonging to the thicker shank portion 41 is within the pressure chamber 43. Pressure-tight guideways 44, 45 for the thicker sections, respectively thinner or respectively thinner portions of rods 41, 42 are provided at the ends of the pressure chamber 43. The pressure chamber 43 is connected to the

  inner annular chamber 33 by a channel 46.

  The thick portion of rod 41 is of a diameter

  be somewhat weaker than the outer diameter of the valve seat 18. Therefore, the pressure

  pressure side exerts a closing force on the

  30, although this force is relatively small.

  compared to the inlet side pressure. This

  favorably affects the size of the

  tioning. The pressure in the annular chamber

  However, this opening force is substantially compensated for by the pressure acting in the pressure chamber 43 on the free frontal surface of the part.

  thick of stem 41, since this pressure equals

  worth constantly to that prevailing in the annul-

  Inner section 33. The thicker part of the stem 41

thus as balancing piston.

  The pressure on the inlet side is established in the inner annular chamber 33 as soon as during the closing process, the second slide 31 bears against the sealing surface 35 on the valve seat 34. It also reigns there immediately after the first drawer 30 came in support with the

  sealing surface 32 on the valve seat 18.

  Then in any case, the pressure can drop in the inner annular chamber 33, for example during the

fluid cooling included.

  If the throttle valve is opened when the pressure has dropped in the inner annular chamber 33, it follows with the lifting of the sealing surface 32 of the valve seat 18 in the inner annular chamber 33 an increase in pressure up to the value on the input side. The resulting elevation for the opening force acting on the slide 30 is however largely compensated by the pressure chamber 43 and the thick rod portion 41. Therefore, the actuation force required

  the uprising of the drawer 30 does not change

  important, for example, even when using a pneumatic actuator, the opening movement is continued continuously, and an opening movement by

involuntary jerk is avoided.

Claims (7)

  1) A throttle valve comprising a valve housing, a throttle element disposed in the valve housing, which has a valve seat, a longitudinal channel and a group of radial throttle channels; a closing portion, which has a drawer located in the longitudinal channel,   running in the area of the foreign channels   and a throttling surface cooperating with the valve seat; characterized in that the throttling element (19-20) has at least one additional group of radial throttle channels (14), observing in the longitudinal direction of the throttle member at least two of the groups throttling channels (14, 20) are arranged at a distance one behind the other; the closing portion (9) has at least one additional drawer (31), which is movably arranged to execute a stroke in the longitudinal channel (8), in the channel group area   additional throttle (14), a canceled chamber   inner (33) is located in the long canal   tudinal (8), each time between two drawers (30, 31);   at least one annular chamber (26) is provided.   which surrounds the throttling element in the region of a group of throttle channels (14), and the throttling element (12-29) each has at least one passage channel (15). ) radial between two groups of throttle channels (14-20) arranged   behind each other, this in the long-term direction   of the throttle element (19-20),   linking an inner annular chamber (33) and a outer annular chamber (26).   2) Throttle valve according to the   cation 1, characterized in that: the element of foreign   (19-29) has an additional valve seat (34) in the area of the additional throttle channel group (34), the closure portion (9) has an additional sealing surface (35) in the zone of the additional slide (35), surface cooperating with the additional valve seat (34), and the two sealing surfaces (32, 35) of the closing part (9) are movable relative to the other way to run a limited race.   30) Throttle valve according to the   cation 2, characterized in that a slide (30) of the closing part (9) is provided with a receiving bore (36) open towards another slide (31), a connecting rod (37) emerging in the receiving bore (36) is provided on the other spool (31), which rod has a stroke drive (38) inside the receiving bore (38), and in the receiving bore (36), one (30) of the drawers has a travel stop (39) for training racing (38).   4) Throttle valve according to the   cation 3, characterized in that a spring (40)   citing the connecting rod (37) in the direction of the   valve is placed in the receiving bore tion (36).   ) Throttle valve according to any one   of claims 2 to 4, characterized by a   balancing piston (41) connected to the first spool   (30), observing the direction of flow of   passing through, and a pressure chamber (43) receives   the balancing piston (41), a chamber connected to the inner annular chamber (33) and whose internal pressure urges the balancing piston (41) into   the direction of closing the valve.   6 ') Throttle valve according to the   cation 5, characterized in that the closure part   tion (9) has at its end located high   pressing an actuating rod, which presents to the   forming a thicker shaft portion (41) and, at a distance from the obturating portion, a thinner shaft portion (42), the actuating rod passes through the pressure chamber ( 43), the front surface of the thicker stem portion (41) and located at a distance from the sealing portion   being on that occasion in the room of   (43), a pressure-tight through-channel (44) for the thicker shaft portion (41) is provided at one end of the pressure chamber   (43) and a pressure-tight through-guide (45)   for the thinner rod portion (42) is disposed at the other end of the pressure chamber (43).   7) Throttle valve according to any one   conque of the preceding claims, characterized   by a seat ring (17) disposed between the groups of throttle channels (14, 20) of the throttle element (12-29), the ring having at its edge   the valve seat (18) intended for the   shutter (9) and at its outer edge a   protruding rear projection (22), a seal of   a gap (24) applied to the rear projection (22), a casing wall (5) radially surrounding the valve seat (17) and the seal (24), a spacer tube (28) one of its ends on the seal (24), tube surrounding at a   end of the throttling element (12-29) and   both radial throttle channels (29), and holding means (7) acting frontally on the   spacer tube (28) and the other choke element (19).   8) Throttle valve according to the   cation 7, characterized in that the channels of   (29) located in the spacer tube (28) and the throttle channels (20) in the adjacent portion (19) of the throttle element are mutually laterally offset and the spacer tube   (28) of the throttling element (19) surrounds the element   throttling member (19) with radial spacing   (28) which is weaker than the free passage of throttles (29, 20).   9) Throttle valve according to one of   preceding claims, characterized by a ring   base (12) disposed at the end of the element   (12-29), having on its outer edge   a peripheral rear projection (21), a seal (23) applied to the rear projection (21), a casing wall (5) radially surrounding the   seal (23) and the base ring (12),   king having an axial stop (6) for the ring of   base (12), and a spacer tube (25) extending   be the seal (23) and the base ring (12) and the seat ring (17), surrounding tube with a   radial distance (26) from the section (13, 16) of the   throttling tightly axially between the two rings (12, 17).   ') Throttle valve according to the   9, characterized in that the ring (12)   feels at its inner edge the other valve seat   (34) for the sealing portion (9).   11) Throttle valve according to one   any of the preceding claims, characterized   characterized in that the parts of the throttle element (12-29) having a group of throttle channels (14-20) each consisting of a set of bushings (13, 19) inserted into each others, with   radial throttling channels (14-20).