DE1960735C2 - Switching valve for compound meter - Google Patents

Description

The invention betrilit a changeover valve for Ver buntlzUhlcr in which a bewegbures within the retrains · venlilgehlluses in the axial direction Schließorgnii is betUtigt by the flow pressure cleir Mcßflüsslgkeit in the main line and this opposing force, which is increased in the final closing phase. Changeover valves are connected to a main flow line, which has a main cooler, and to a secondary flow line, which is provided with a secondary cooler. The secondary meter is used to measure small flow rates, while the main meter determines large flow rates in a corresponding manner.

In addition to the reversing valve type discussed at the beginning, there is another type that is particularly frequently used known, in which the mouth of the main line is closed by a valve body which is held in its locked position by a rigid or moveable weight. Through the Flow pressure is contrary to the effect of the ao Weight of the valve body lifted from the seat. In such arrangements it is also known to control the flow from the secondary meter at the same time by moving the flap body. This happens for example by having the main and secondary lines in a common housing space open, which has the advantage that the entire Strönningsdruck can be used for control processes.

In the two types of switching valves discussed, there is a significant disadvantage that the change from secondary meter operation to main meter operation cannot be reached with exact flow conditions, but the main counter when it increases the flow rate starts too early and bi; i decrease the flow rate has been in operation for too long. This affects the measurement accuracy considerably, and the DiN 19 625 takes account of these deficiencies that have not yet been remedied by approving a Measurement error in unlimited height in the specified switching range of the compound meter. To the limit this measurement error and the switching range are devices, such as permanent magnets, changing Weights and the like., Known to initially increase the pressure in front of the valve body which is still closed build up for a sudden opening and closing of the flap in the interest of measuring accuracy is required. However, these devices are only partially satisfactory because they are precisely closed not be made possible.

The use of permanent magnets in a switch valve of the type explained at the beginning This is because it only provides an exact transition to main meter operation when the main line is opened secure. This is due to the fact that the permanent magnet increases the size of the gap has a steeply decreasing force characteristic and is therefore only effective when closing in the very last shooting phase is, d. h. | also the increased clamping force must be applied by the spring member, the force of which has already decreased in this area and which would therefore have to be designed to be correspondingly strong. This in turn disrupts the operation in the somewhat drained area Position of the closing organ in that it "flutters". Towards the ones required in the closing phase To be able to apply high forces, the 6g magnets must be designed to be strong. This has large dimensions and result in considerable weight, which necessitates large and heavy valve housings power. Furthermore, the design and processing costs are considerable, the latter is particularly true Dimensions for flap valve, especially when improving the control effect through curved Throttle bodies can be reached in the coil the Bewugiingsbahn of the valve body arranged are.

The aim of the present invention is to eliminate the disadvantages mentioned, and in particular to sound a switching valve that excludes measurement errors in the switching area, in which the closing element relieved more effectively than before in the oil position and that is significantly lighter than the previously known designs.

This is achieved according to the invention in the reversing valve explained in more detail at the beginning, that a first spring member is provided, which the closing member only in the immediate area of the seat lying part of the actuation path is acted upon by a control force, the closing member through a hydraulic pusher can be moved, which is constantly in front of the differential pressure of the measuring fluid and is acted upon behind the closing member and a force counteracting this, and the When the closing member is opened, the handle is lifted from it, after opening it by removing the Pressure difference moves in the direction of the closing member and this against and as a function of from the flow pressure of the measuring fluid until after covering a certain one Stretch the first spring element takes effect and suddenly pushes the closing element into the blocking position.

According to a further feature of the invention, only the first one acts directly on the closing member The spring element is set to the switching pressure of the valve and that of the hydraulic trigger the force applied to the closing element is much smaller.

In this way, according to the invention, it is ensured that a large closing force is exerted on the closing element acts, while in the open position a particularly sensitive adjustment to the flow conditions and thus movement of the closing member is achieved, which is due to the fact that the hydraulic trigger as a function of the total pressure the measuring liquid in the main line can be controlled. For an exact activity of the main meter the final phase of the closing path of the closing element is decisive. With the known flap valves is a jerky prevention of the inflow from the main meter due to the geometric or structural conditions not possible, especially since the dynamic pressure of the moving fluid column on the closing surface of the valve body is fully effective. To the Reduction of the dynamic fluid pressure from the movement of the closing member to a certain extent To make degrees independent is provided according to a further feature of the invention, that the closing member has an auxiliary valve which is also in the open position of the Schüeßorgans is open and is only closed suddenly towards the end of the accelerated closing phase.

The same effect can be obtained in that According to a further feature of the invention, the closing member has a throttle member which is in the accelerated closing phase, the total flow of the main and secondary meter is briefly and severely throttled.

This throttling action also affects the open at 60 is durgestellt an auxiliary valve that

the closing member is advantageous, since it is assigned to the closing member 50. The plate 52 knows

It is known that all of the fluid pressure passes through the through bores 61 on the circumference

Closing member quickly into the new: position over the plate 52 are uniformly distributed and those leads. ^ -5 Number and size depending on the respective

The drawing shows exemplary embodiments of the flow parameters. Furthermore is dei

Invention reproduced on the basis of the after-plate 52 with three bushes distributed around the circumference

The following description is explained below. It 62 is provided in which pins 63 are slidably guided

^zti 'gt The Sliite 63 connect an auxiliary valve disk 64 mi

F i g. I a section through the switching valve in io a stop 65 on which a ring 66 with radial

the rest position, arms 67 is arranged, which by the opening egg

Fig. 2 shows a further form of filling of the liquid that encounters no resistance whatsoever.

switching valve, oppose. Between the arms 67 and the ent

F ί g, 3 to fi schematically different operational-speaking surface of the plate 52 is one

Positions of the switching valve, explained on the basis of the 15 weak compression spring 68 provided, Die Druckfedei

Embodiment according to FIG. 1, and 68 presses over the arms 67 and the pins 63 of the

7 shows a plate 64, modified compared to FIGS. 1 and 2, against the upstream surface

Embodiment. of the plate 52, whereby the oiling 61 closes

In FIG. I, a housing 10 is shown for switching over.

valve shown, to which at 11 a main line, the 20 The plate 64 of the auxiliary valve 60 is by means of one

comes from the main meter, connected is uiid at hub 69 movable on the circumference of hub 51 de:

12 a secondary line stored by a secondary meter closing element 50. At the front free end

comes. At 13, the entire measuring liquid emerges from the hub 69, there is a projection 70, the free of which

the changeover valve housing. The secondary line surface 71 with the corresponding surface de;

branches off in front of the main meter and is during the bearing 23 can be brought into engagement. Fcrnci

the entire measuring process acted upon with liquid. the hub 69 is provided with a shoulder 72, ir

The switchover device represents a unit which has three spring elements 72 distributed around the circumference

can be inserted as a whole into the housing 10 and is also supported, the one ball 74 against the outer

by means of a flange 21 on a fiehäusevoisprung perimeter of the hub 51 press. At 75 there is a notch

14 can be attached. The flange 21 is indicated on a 30, of which also three on the Umfanj

cylindrical seat / body 20 arranged. From the circumference of the hub 51 are provided distributed and in the dii

of the seat body 20 extend radially to the center two corresponding balls 74 snap. To the auxiliary

or three ribs 22 in the middle of a bearing 23 valve 60 regardless of the movement of the closing

exhibit. In the bearing 23 an axis 24 of the rotating member 50 is to be kept in the open position, fills

fixed, but the axis 24 compared to 35 no special control forces on the auxiliary valve 6 (

the bearing 23 is adjustable in the axial direction. Which are effective.

Axis 24 has a central bore 25, which is also a hydraulic one on axis 24:

Main line 11 connects to a nozzle 26. Mounted pusher, which is generally designated 80

On the outer periphery of the seat body 20 are di- The pusher 80 consists of a disc-shaped)

inetrally opposite, preferably two bearing pistons 81, which are designed in one piece with the axis 24

Bock 27 is arranged in which rods 28 can be pivoted and a you on the outer circumference

are managed in cash. Has the outer free ends of the processing ring. The piston 81 is of a

Rods 28 are overlapped by two spring elements 29 with cylinder 82, which by means of a Stimwanc

connected to one another, which is provided with a hub 84 by means of corresponding pins 83. The hub 84 is

30 are hinged to the rods 28 so that the 45 slidably guided on the axis 24, the in dei

Springs 29 on both sides of the axis 24 freely moving work space 85 facing part of the hub 84 with a

are cash. Recess 86 is given away, through which the nozzle 2 <

One protrudes into the work space 85 depending on the required. The free edge of the ii

Force application selectable point between the part of the hub 84 protruding from the working space 85

Bearings 27 and the pins 30 have the rods 28 50 denoted by 87 and forms together with de

Bearing blocks 31 for rollers 32 on. Spice! of the piston 81 a stop and dami

The closing element is generally designated by 50, a limitation for the cylinder movement,

and consists of a hub 51 which slides on the outer free surface of the plate 83 win

Axis 24 is guided. The hub 51 has one acted upon by a spring 88, which acts as a screw

radially extending Tejler 52, the spring on the upper 55 between the plate 83 and a stop S '.

free end is biased with a cylindrical portion 53 which is adjustable on the axis 24

is provided. Is arranged on the outer circumference of the plate 52.

There is a cylindrical sealing surface 54, while the cylinder 82 has a smaller diameter

rend on the end face of the cylinder S3 a radial one than the cylinder 53 of the closing member 50 and protrudes

Sealing surface 55 with a sealing ring 56 extends out 60 into the cylinder 53. The front free forehead

is formed. Downstream, the cylindrical section surface of the cylinder 82 is denoted by 90 to

53 an inclined control surface 57. The control surface forms a radial ring surface that connects to the Armin 6 '

57 forms together with the free surface 58 which can be brought into engagement.

Cylinder 53 the cam track for the rollers 32, where- Fig. 2 shows a further embodiment de

the switching point is at 59. In the rest position 65, the compression-enabled valve, with the corresponding!

can ti ic Lagt: the rollers 32 by a zyündri- individual elements of the embodiments according to FIG.

see collar on the cylinder 53 to be fixed to a con and 7 through the individual elements of this execution

The spring 29 must be pretensioned. shape are replaceable.

The first frame consists of two storage buckets 127, which are arranged diametrically opposite one another on the clasp and a rod each 128 (lay. The outer free linden of the poles

128 are connected to one another by two spring elements 129 connected, which are articulated by means of corresponding pins 130 on the rods 128 that the springs

129 ϊμ both sides of the hub 51 are freely movable. The pins 130 can be fixed on the rods 128 so as to be displaceable in their longitudinal direction in order to increase the pre-tensioning of the Feilci. Between the bearings 127 and the pins 130, the rods 128 have bearing blocks 131 for rollers 132. It is not necessary here to incorporate the embodiment shown in FIG. The closing element 50 lies tightly against the seat 20 under the action of the spring element 27 to 32. The spring 68 presses the plate 64 of the auxiliary valve 60 against the upstream face of the

Plate 52. The through bores 61 are thus also closed.

The pusher 80 is also in the rest position, with the compression spring 88 opposing the hub 84 pushes the piston 811. Between the surface 90 and

ίο the arms 67 is advantageously some play.

If the secondary meter now slowly starts to work, the measuring liquid flows from the opening 12 Secondary meter in the switching valve housing 10. First, the arrangement is still the position according to

iuniisfonu ". Rather, the first spring 15 Fig. 3 can be retained, but with increasing organ be designed so that the rollers 132 un- differential pressure of the pusher 80 actuated by over

"'■ the bore 25 of the flow pressure from the main

Line 11 enters the nozzle 26 and thus into the working space 85 of the trigger 80. The movement of the cylinder 82 takes place as a function of the pressure difference on both sides of the disk 83. In this case, the pressure difference of the liquid on both sides of the disc 52 of the closing member 50 corresponds. The compression spring 88 advantageously has a flat spring characteristic with a Preload, which corresponds approximately to the pressure loss of the secondary meter corresponds to half of the power required for the switchover. The lounging area of the secondary meter is usually a service.

are indirectly rotatably arranged on the pins 130, which then au the front free ends of the Rods 128 are fixedly mounted. The bearing blocks 131 then omitted.

The hub 51 is elongated compared to FIG. 1 and has control surfaces 157 and 158, which are separated from one another by a switching point 159 are. More finely, a cylindrical dog 151 is formed on the hub 51, on which in the closed as In the position of the valve, the rollers 132 rest, but at the same time they are in engagement with the surfaces 157. In this way, a constant pretensioning of the springs 129 is ensured. The cylindrical section

Springs 12 secures y

53 on the valve disk 52 is omitted in this embodiment 3 = when pressure losses of up to 2 mWS occur.

ninrsform. the following to be explained Organ 91 according to Fig. 7 directly on the Telia 52 is on.

To simplify the assembly, this version has a function the piston 81 with a bushing 181 and fastened on the axis 24, with a Durchganjisbohrung 126 the connection between dei / entralbohruni: 25 and the work room 85 ensures. The stop 87 of the pressure cylinder If the differential pressure approaches the switchover value - according to DTN 19 625 max. 2 raW'S - so takes the pusher 80 the position according to Fi g. 4 a. The first Spring element 27 to 32 exerts the pressure on closing element 50 in the axial direction that corresponds to the switching pressure is equivalent to.

If the transfer pressure of 2 mWS is reached, see the closing element 50 opens suddenly, in that the roller 32 moves upwards on the control surface 57

82 83 is here in the form of the Hache 187 40, the switching point 59 exceeds and on dei

Surface 58 rolls off. Thus exercises the first spring member 2 "to 32 no axial pressure more on the closing member from. So look to move this under the Sirörvnines- • .i ^r" ck free ninial the DiiiekerSO ru · <5 next is lifted from Schiicßorgan The sehlag A similar opening of the closure member 50 is brought about by a sealing 48 which slidably seals on the sealing surface 54. The roller 32 reaches the starting point 59 and the connection with the roller 32 .mf lhiem Wei hintcT the switching punk; 50 decreasing \\ ialdruci the Sehhcßoipan 50 SM.vi n.vh citoietct Oflnuni takes dei overpressure F ι ■ £ J ^'1 m the \ ibcitsraun from and dei Duiekei 80 bewcpt si _v h. cem.iss lic!

np'-h left towards d.is Schlutvve.in 5fl During this movement infti the tieie k.ntcOI of the Ahndi-vs82 on the \ rnie 6 "? and prints there Auxiliary valve W) into the peoflnctc Stelhmr IXm 1 <»■

• \ rrnc 67 one is lifted from the opening pc «(M, and di

an .let See S3 Alternatively, the hub 84 can only formed within the pressure chamber 85 be, the Ansehläge adjusted accordingly are

According to this form of notification, Γαnei can * wide Federorcan 88.89 within the pusher 80 be arranged, vvwu the cylinder S2 with a Uimd 1S3 vei-iohon i * t. rustling him and that as AnseM.K 180 trained disc 81 cmc compression spring 188 is arranged, the federal government 183 can with screwed to the free Jew des 7 \ hnders82 « odct by a ledanp cebiKiet will picse • Vusiuluuncsfonii cest.ittet a veikinrtc training da - \ clise 24 imd cunoclvhi as crw.ihnt above <iie p.M ^ eie Freihen bc7uchch dci Ge-Staltunide; Hub 84 \ 'le dic «e Meikmalc pcstattcn cmc Vo: n) Viktere construction of the l'mschaitvcntil-

Vann on
\ er \\ em1et

See det «Erxien. the

S2 mn a ktwrcntnscbcn is the interior of the Drockm »nvi damn the first» md dis tvcvk Fcderorjsiui

de * 6f Kuccln 74 pelanpen tnu den KaKn 75 \ r \
I ⁴ TO BV m «» 8

Xn Y 1 ρ

ι- «5

j «F15? «Stretch wspnclrt

rnnh are

nwt Fig.!

With this \ orpani: the
l> amn the Fcdct SS is practiced
dw Orpamc l »5 to *» 7 on that
".at the. «Ml fjcmiiß lic 5 can do that
ΛΝίΛηριρί. «" \ S "m the Siriwnui):
la «irt back and forth borbpwvjyt wcnVn

FaHi An Strctnrontrsdmek a «td;» s
«Oil (WS Wen. D« untrhMh des

8 «urn

is, the closing member 50 assumes the position shown in FIG. If the handle 80 reaches the stop on the piston 81, the roller 32 has already slightly exceeded the point 59, and the front free one Edge of the sealing flats 54 has the lip sealing ring 48 in the sealing surface 49 of the seat body 20 detected. The water must now flow exclusively through the bores 61. The further movement of the Closing member 50 is now determined on the one hand by the axial thrust of the spring member 27 to 32, on the other hand by a counteracting force that reduces the pressure loss occurring in "the bores 61, based on the total cross-section of the closing member 50, corresponds. These holes are dimensioned so that a further movement in the direction of closing only takes place when the flow rate is below the The value that is required to open the closing member 50 has decreased. If this is the case, it pushes first spring member 27 to 32 accelerates the closing member 50 further in the direction of the seat body 20, wherein In the last phase of this movement, the surface 71 on the extension 70 with the corresponding opposite Surface on the bearing 23 comes into engagement. The balls 74 are thereby removed from the notches 75 pushed out, and under the action of the dynamic pressure and the spring 68, the plate 74 moves towards the plate 52, whereby the openings 61 are locked. Since the pusher 80 rests against the stop, the arms 67 can move freely and take the position according to FIG. 3 a. Between the approach 70 and the front free radial surface of the hub 51 occurs during the closing process a certain damping, the possible damage switches off on the auxiliary valve due to excessive slamming. The closing process is finished, as soon as the sealing ring 56 comes to rest on a radial end face 46 of the seat body 20. The switching valve is then in the position shown in FIG. 3, with the secondary meter at most running. When the pressure increases again, the pressure changes are repeated according to FIG. 3 to 6 in a corresponding manner.

Due to the effective relief of the main locking element in the OITcn position, this can be undesirable The secondary counter runs along shortly before · the closing process can be prevented by installing a non-return valve with low pressure loss in the connection line.

The first Tedcrorgan 27 to 32 can also be designed in a different way. For example, as shown in FIG. 7 can be seen, on the housing 10, evenly distributed over the circumference, guide bushings 40 for springs 41 and pins 43 can be provided, on the free locations of which rollers 42 are mounted. The rollers 42 then act on the control surfaces 57 and 58 in the same way as the rollers 32. The only essential thing here is that both the rollers 32 and the rollers 42 exert a uniform pressure on the closing element 50 over the entire circumference so that it is completely closed is pressed against the seat body 20 or remains freely movable on the axis 24.

F'crner is in the embodiment, F i g. 7 the auxiliary valve 60 with the organs 61 to 75 omitted. The pusher 80 acts with the radial abutment surface 90 directly on the closing member 50, for which purpose the cylinder 82 is correspondingly lengthened. In place of the auxiliary valve * 60, a disk-shaped projection 91 is provided around the outer circumference of the cylinder 58 of the closing element 50 , which cooperates with an annular projection 92 on the inside of the housing 10. In Fig. 7, the switching valve according to this Ausführungsforni is shown in the rest position, the F i g. 3 corresponds. The position of the disk is shown in dashed lines at 95

91 reproduced what the operating state according to F i g. 5 corresponds. The position of the disk 91 in the operating state according to FIG. 6 is shown with 96. In detail, this means the following. Are located If the discs are in position 91-92, then the rest position is present or the secondary counter is running «. In the position Main and secondary meters are running 95-92. At position 96-92, further movement of the closing member 50 determined on the one hand by spring elements 40-43 and 88, on the other hand by a counteracting one Force corresponding to the pressure loss caused by throttling 92-96, based on the overall cross-section of closing organ 50, enlarged by attachment 91.

The distance between approach 91 and projection

92 is dimensioned so that further movement of the closing member 50 in the closing direction does not take place until when the total flow rate (main and secondary meters) has fallen below the value that was used at opening was required. If this is the case, so happen! the approach 91 the projection 92, the free passage cross-section is suddenly expanded, which the both spring organs counteracting force falls as a result, suddenly and enables the closing member 50 to close suddenly.

The opening of the closing organ is just as sudden, since a movement of the closing member 50 immediately results in a throttling of the passage cross-section and the closing member 50 is thereby forcibly moved into the position 92-96.

In this position the flow is distributed to the main and secondary meters according to their flow rate, d. i.e. the amount flowing through the secondary meter is only a small fraction of the total flow, so that the main meter is loaded with certainty with a flow force that is within of its measuring range and is therefore precisely exempted.

In addition to the increased measurement accuracy wedge and low thickness loss, the invention has the advantage that the switching valve can also be installed in any inclined position and is operationally safe The housing 10 is considerably smaller and lighter than the previously known Umschaltvcntilgchäuse, and dei Insert 20 to 91 is a compact unit, each row adapted to different flow conditions interchangeable. This also considerably simplifies maintenance. The interchangeable inserts can be delivered pre-adjusted and can also be installed by vvcnigci skilled assistants.

Claims (15)

Patent claims: 1. Changeover valve for compound meter. in which one within the environs of axial direction movable SchlicBorpnn diircli the flow pressure of the measuring fluid in the Main line and a force counteracting this, which is suffered in the last phase of vision, is operated, characterized in that that a first spring member (27 to 32, 40 to 43, 127 to 132) is provided, which acts on the closing member (50) only in the immediate area of the seat;: fnichen (46, 49) lying part of the actuating path with a control force that Closing member (50) can be moved by a hydraulic pusher (80) which is constantly acted upon by the differential pressure of the measuring fluid in front of and behind the closing member (50) and a force counteracting this, and the pusher (80) when the closing member (50) is opened this is lifted, after opening by decreasing the pressure difference moves in the direction of the closing member (50) and this takes it against and depending on the flow pressure of the measuring liquid, until after covering a certain distance the first spring member (27 to 32, 40 to 43, 127 to 132) becomes effective and the closing element (52) suddenly pushes into the blocking position. 2. Valve according to claim 1, characterized in that only the first spring element (27 to 32 _Λ 40 to 43, 127 to 132) acting directly on the closing element (50) is set to the switching pressure of the valve and that of the hydraulic pusher (80 ) the force applied to the closing member (50) is much smaller. 3. Valve according to claim 1 or 2, characterized in that the closing member (50) a Auxiliary valve (60) which is also open in the open position of the closing member (£! 0) is and only closed suddenly towards the end of the accelerated closing phase will. 4. Valve according to claim 1 or 2, characterized in that the closing element (50) is a Has throttle member (91), the total flow of in the accelerated closing phase Main and secondary meter throttles strongly for a short time (Fig. 7). 5. Valve according to one of claims 1 to 4, characterized in that the closing member (50) and the cylinder (82) of the hydraulic trigger (80) on a rigid housing axis (24) are reciprocable. 6. Valve according to claim 1, 2 or 5, characterized in that the hydraulic pusher (80) consists of a piston (81) which is fixed on the axis (24) and from which on the housing axis (24) movable cylinder ( 82) is overlapped, and the housing axis (24) has a central bore (25) which is in communication with the main line (11) and which is in communication with the handle working space (85), and a second one against the movable cylinder (82, 83) The spring element (88, 188) presses and thus represents the force counteracting the pressure difference. 7. Valve according to claim 6, characterized in that the cylinder (82) of the hydraulic The pusher (80) has a collar (84) which in the rest position on the piston (81) under the action of the second spring member (88) and below Maintaining the connection between the handle work area (85) and the central bore (25) is applied (Fig. 1). 8. Valve according to claim 6, characterized in that the piston (81) of the hydraulic pusher (80) has a bushing (181) on which in the rest position the surface (187) of the disc (83) under the action of the second spring member (188) is applied, the connection of the handle working space (85) with the central bore (25J by a bore (126) is ensured (Fig. 2). 9. Valve according to one of claims 1 to 3, characterized in that a plate (52) of the Closing member (50) through the auxiliary valve (60) controllable openings (61) which at certain Flow parameters are adjustable. 10. Valve according to claim 9, characterized in that the openings (61) through an in Closing direction by a spring (68) loaded valve plate (64) can be closed by means of Pins (63) in the plate (52) of the closing member (50) is slidably guided and no noticeable downstream Has flow resistance-inducing arms (67) from a free edge (90) of the Cylinder (82) of the hydraulic trigger (80) are beaiisch'iagbar. IL valve according to claim 9 or 10, characterized characterized in that the spring (68) is weaker than a latching element (74, 75) for fixing the valve disk (64) in its open position. 12. Valve according to one of claims 1 to 11, characterized in that the first Fecerorgan (27 to 32, 40 to 43, 127 to 132 ) exceeds the switching point (59) and becomes effective shortly after the front edge of a cylindrical sealing surface ( 54) of the closing element (50) with a main sealing ring (48) a seat surface (49) has come into engagement, the sealing surface (54) and the ring (48) remain in engagement during the accelerated closing phase and the first spring member (27 to 32, 40 to 43, 127 to 132) holds a sealing ring (56) in engagement with the seat surface (46) ″ in the closed position. 13. Valve according to one of claims 1 to 12, characterized in that the first Fecterorgan (27 to 32, 127 to 132) consists of two rollers (32, 132) arranged on a lever transmission, which on an inclined control surface (i »7 , 157) roll on the closing element and are connected to one another in such a way that a uniform axial thrust is exerted on the closing element (50) at diametrically opposite points. in the closed position of the closing element (50) a constant preload of the springs (29, 129) of the first spring element can be achieved by a cylindrical collar (151) on the hub (51) or on the cylinder (53) of the closing element (50) . on which the rollers (32, 132) rest. 14. Valve according to one of claims 1 to 12, characterized in that the first spring member (40 to 43) consists of a guide (40) which is attached to the housing (10) and a spring (41) and a pin (43) receives, at the free end of which a roller (42) is mounted which is in engagement with the control surface (57) or the cylindrical outer surface (58) of the closing element (50) (FIG. 7). 15. Valve according to claim 1, 2 or 4, characterized in that as a throttle member on the outer circumference of the cylindrical closing aran (SO) a radially extending disc (91) is arranged, the free edge of which with one on the valve housing (10) fixed control edge (92) cooperates so that, in addition to a throttle position, different Control positions are present (FIG. 7). . For this purpose 2 sheets of drawings