Membranventil

Abstract

Diaphragm valve (V), particularly for aseptic processes, with an actuator for adjusting a diaphragm (5) made of elastomeric material by means of a pressure piece (11) relative to a valve seat (21), wherein the diaphragm (5), which is fixed in the edge region, is acted upon circumferentially and permanently outside the valve seat (21) by a spring system in a housing intermediate piece (1), characterized in that a pressure sleeve (D) movable in the adjustment direction (25) is arranged in the housing intermediate piece (1) as a spring system, which automatically compensates for the settling behavior of the diaphragm (5) and comprises a ring base (13) guided in the adjustment direction (25) in the housing intermediate piece (1) with several, preferably four, circumferentially separated, axially stiff, resilient spring cheeks (15) transversely to the adjustment direction (25), which project upwards from the ring base (13) and have ramp-like edge regions (18) at their free ends.which are under preload against counter ramps (22) in the housing intermediate piece (1).

Description

[0001] The invention relates to a diaphragm valve according to the preamble of claim 1.

[0002] Known diaphragm valves of this type, used, for example, in aseptic processes and designed for nominal diameters of approximately 3.0 mm to 100 mm, feature a ring spring assembly around the valve seat to actuate the diaphragm, a one-piece spindle screwed into a nut and axial bearing, and direct transmission of the spindle pressure to the pressure piece. These known diaphragm valves suffer from the disadvantages of insufficient operational reliability, high maintenance requirements, and, for example, unnecessarily large dimensions and / or strokes of the handwheel in the adjustment direction of the pressure piece. Operational reliability is compromised because the diaphragm exhibits a settling behavior that changes during sterilization at high temperatures and cannot be reliably compensated for internally by the spring system, necessitating external adjustment, e.g., of the housing spacer.

[0003] German patent DE 10 2015 202 775 A1 describes a diaphragm valve in which a spring system arranged in a housing intermediate piece is designed as a spring assembly with several disc springs connected in series and positioned by a clamping ring. A clamping nut sits on the uppermost disc spring, into which a threaded sleeve is axially screwed. The clamping nut and the threaded sleeve are screwed together via a trapezoidal thread, with the spring retainer thus formed sitting on the edge of a diaphragm and holding it in a diaphragm receptacle on the upper side.

[0004] DE 102 46 912 B3 discloses a diaphragm valve comprising a diaphragm valve body, a diaphragm, and a handwheel connected to a threaded spindle. The threaded spindle has a thread that engages a corresponding thread on a lifting element. When the handwheel is turned, the thread of the threaded spindle engages a corresponding thread on the lifting element, moving the lifting element up and down relative to the housing. Rotation of the lifting element against the thread is prevented by a guide integrated into the housing. No further details are provided regarding the circumferential fixation of the diaphragm.

[0005] In another diaphragm valve shown in DE 12 91 584 A, stacked disc springs are also provided to press the diaphragm against it, acting on the top of the diaphragm via pressure pieces.

[0006] Furthermore, DE 10 2014 012 173 A1 shows a diaphragm valve, wherein a diaphragm compensation equalization is based on the disc spring principle in conjunction with a pressure sleeve.

[0007] The invention is based on the objective of creating a diaphragm valve of the type mentioned above that is characterized by increased operational reliability, reduced maintenance effort and compact dimensions.

[0008] The task at hand is solved using the features of patent claim 1.

[0009] The pressure sleeve, through mechanical interaction with the housing intermediate piece, not only generates the necessary compression of the diaphragm around the valve seat for a perfect seal, but is even capable of automatically compensating for changes in the diaphragm's settling behavior. This ensures increased operational reliability and eliminates the need for external adjustments. Additional advantages of this cost-effective pressure sleeve include simplified assembly, reduced installation space, reduced weight, a single component for two functions, and freely selectable force / stroke ratios.

[0010] In the embodiment of the diaphragm valve according to the invention, either as a manual valve or, for example, pneumatically actuated, the pressure sleeve, preferably made of high-strength steel material such as cast steel or spring steel, has a ring base guided in the housing intermediate piece in the adjustment direction with several, for example, four, axially rigid but transversely resilient spring cheeks separated in the circumferential direction, which project upwards from the ring base and have ramp-like edge areas at their free ends which bear against counter ramps arranged, for example, in the housing intermediate piece, under preload.The spring-loaded cheeks act like bending springs laterally supported by the counter ramps. These springs exert tension forces on the diaphragm via the ring base in the adjustment direction, automatically adjusting and largely maintaining these tension forces to the diaphragm's settling behavior by moving back and forth along the counter ramps under bending stress. For example, if the diaphragm settles after a high-temperature sterilization phase (e.g., above 120°C), meaning its thickness decreases, the ramp-like edge areas slide outwards along the counter ramps under bending stress. This causes the pressure sleeve in the intermediate housing to move downwards, ensuring that the tension on the diaphragm remains nearly constant despite its reduced thickness and thus guaranteeing a tight seal.If, however, the diaphragm thickens after being set during operation, the edges of the spring flanges are pressed inwards against the counter-ramps, and the pressure sleeve slides upwards, while the preload force on the diaphragm remains largely unchanged. It is therefore advantageous to install the pressure sleeve in a preloaded state, for example by appropriately positioning the housing intermediate piece relative to the lower housing part.

[0011] According to another important aspect with independent inventive significance, the diaphragm valve, if designed as a manual valve, features a two-part telescopic spindle, actuated by a handwheel, for adjusting the pressure piece. The spindle sections can be screwed together via opposing self-locking threads, with the opposing thread pitches adding in the adjustment direction. Thanks to the two-part spindle, the diaphragm valve has a reduced size in the adjustment direction, particularly a significantly reduced handwheel stroke and a lower number of handwheel revolutions despite the self-locking threads. The reduced stroke refers to the axial movement of the handwheel when, for example, one spindle section is screwed into the intermediate housing piece and the other spindle section is screwed into the other. The weight of the two-part spindle is low. An axial bearing is unnecessary, as the threads perform this function.The axial handwheel movement and the number of handwheel revolutions are freely selectable.

[0012] According to a further aspect with independent inventive significance, an adjustable limiting device for the closing stroke and / or the opening stroke is provided in the manually operated diaphragm valve between a handwheel coupled to a spindle and the intermediate housing piece. This is a cost-effective and easy-to-use solution to the problem of being able to freely select the closing or opening stroke of the diaphragm valve. The limiting device is characterized by its simple design and the fact that two functions are realized by a single component, resulting in reduced installation space and weight, in contrast to the multiple components used in the prior art, which are heavier, have tolerances, and require a large installation space.

[0013] According to a further aspect with independent inventive significance, a spring-loaded compensation element is arranged in the pressure piece. This element acts on the diaphragm via the pressure piece, which is adjustable by a spindle. The compensation element reduces the risk of leakage after the diaphragm has settled, for example, after a sterilization process, and even makes it possible to omit a closing stroke limiter to protect the diaphragm. Compared to known solutions without compensation for the settling behavior in the area of ​​the pressure piece, the compensation element in the pressure piece offers the advantage of automatic compensation of the diaphragm's settling behavior.

[0014] In a preferred embodiment, the pressure sleeve is secured against rotation within the housing intermediate piece. This anti-rotation device, for example a lug at the base of the ring in the housing intermediate piece, allows the pressure sleeve to also secure the pressure piece against rotation.

[0015] As an assembly aid, the pressure sleeve can have an external locking lug, for example on at least one spring cheek, so that in the installed state the locking lug is secured against falling out in a locking recess inside the housing intermediate piece and is held, for example, in a pre-tensioned assembly position.

[0016] To prevent the pressure piece from rotating, the anti-rotation pressure sleeve can have at least one, preferably several, circumferentially distributed fingers that project freely inwards from the ring base and / or the spring cheeks. These fingers engage the pressure piece to prevent it from rotating.

[0017] A simple embodiment of the anti-rotation device for the pressure piece comprises at least one U-shaped pocket open at the top in the pressure piece, into which the respective finger of the pressure sleeve engages, but in such a way that axial adjustment movements of the pressure piece are not hindered.

[0018] In the embodiment of the hand valve with the spindle designed as a two-part telescopic spindle, one spindle part, preferably a hollow spindle part with an internal and an external thread, is rotationally fixed but, for example, detachably coupled to the handwheel. The other spindle part, which is preferably a solid spindle part with an external thread running in the opposite direction to the internal thread of the first spindle part (right-hand and left-hand threads), can be screwed into the opposite internal thread of the first spindle part and is rotationally fixed to the pressure piece, optionally with axial adjustment.Due to the opposing threads through which the two spindle parts engage, a slight rotation and small stroke of the handwheel is sufficient to generate a large stroke of the other spindle part, since the thread pitches of the opposing threads add up, with the threads being expediently designed to be self-locking in order to hold the diaphragm valve in the respective set position.

[0019] The spindle section, which can be coupled to the handwheel, has an external thread along at least part of its length, which can be screwed into the intermediate housing piece. This external thread serves an additional function on one of the spindle sections.

[0020] In the embodiment of the diaphragm valve designed as a manual valve, the limiting device for the closing stroke and / or the opening stroke can have a sleeve-like cam that can be screwed onto a spindle adjustable by a handwheel. The cam is equipped with at least one radial stop acting in the axial direction, preferably with a lower and an upper stroke stop. The cam is non-rotatably coupled to the handwheel so that it can be screwed onto the external thread of the spindle by the handwheel and thus axially adjusted relative to one part of the spindle.

[0021] In a preferred embodiment, the housing intermediate piece has an upper ring collar with an internal ring stop. The ring stop can engage, for example, in the screw path of the cam and / or in the pull-up path of the handwheel. The ring stop is, for instance, a spring ring or circlip removable in an inner circumferential groove of the ring collar. This also simplifies the assembly of interlocking components of the diaphragm valve actuator.

[0022] To allow for convenient and precise adjustment of the stroke, it is advantageous for the handwheel to be detachably coupled to the spindle via a fastening element. After releasing the fastening element, the handwheel can be moved to a rotatable, detached position relative to the spindle by pulling it a limited distance away. In this detached position, the handwheel is rotated relative to the spindle to tighten the cam along the spindle. The position of the cam on the spindle determines how far the handwheel, once re-coupled to the spindle, can be rotated, for example, to achieve a specific opening and / or closing position of the diaphragm valve.

[0023] The handwheel can have an outer skirt extending over the collar and either an inner skirt engaging between the collar and the cam, or several partially cylindrical inner skirts distributed circumferentially. At least one inner skirt, or all of them, can interact with a stop in the cam, for example, to define the released position of the handwheel.

[0024] The mechanism is simple and inexpensive to manufacture if it comprises several circumferentially separated foot sections on a ring body that has an internal thread for screwing onto the external thread of the spindle and at least one retaining recess for a handwheel driver. Each foot section has an upper and / or a lower stroke stop on its outer side. The inner lower stop can interact with the end of a tube section of the intermediate housing piece, into which the external thread of the spindle or one spindle section can be screwed. The outer upper stroke stop can interact with the ring stop of the ring collar.

[0025] The compensating element, which ensures constant pressure of the pressure piece against the diaphragm largely independent of the spindle pressure, can be a space-saving, preferably replaceable, ring spring assembly positioned in a blind bore of the pressure piece. This assembly can have an internal bore. A sliding disc can be arranged between the ring spring assembly and the spindle, which is axially fixed within the pressure piece, to better transfer the spindle pressure to the ring spring assembly and thus to the pressure piece, thereby reducing friction. Should the spindle attempt to exert strong pressure on the diaphragm, the ring spring assembly is compressed, so that the pressure on the diaphragm required for sealing remains approximately constant.

[0026] A sleeve with an internal threaded bore for a threaded pin of the diaphragm can be advantageously positioned centrally in the bottom of the blind bore of the pressure piece. This sleeve can be slid upwards from a predetermined lowest end position parallel to the adjustment direction relative to the pressure piece, so as not to exert any additional pressure forces on the diaphragm. In the lowest end position of the sleeve, the diaphragm is locally separated from the seat by the pressure piece according to the opening stroke.

[0027] The drawing illustrates embodiments of the invention. It shows: Fig. 1 A perspective view of a diaphragm valve designed here as a non-limiting example as a hand valve, especially for aseptic processes, Fig. 2 a section of the diaphragm valve of Fig. 1, Fig. 3 a section of a pressure sleeve in the actuator of the diaphragm valve, Fig. 4. One half of an axial section to illustrate the installation position of the pressure sleeve. Fig. 3, Fig. 5 a spindle designed as a two-part telescopic spindle in the drive of the diaphragm valve in section, Fig. 6 a section of three components of the diaphragm valve, Fig. 7. A cut to clarify details of to Fig. 6, Fig. 8 a cut of a backdrop that is in Fig. 7 is shown in the installed position, Fig. 9 a section of a printed piece with a compensation element, Fig. 10 a section of the compensation element of Fig. 9, and Fig. 11 A view of a lower part carrying a membrane.

[0028] A in Fig. 1 and Fig. The diaphragm valve V shown (partially), particularly for aseptic processes, requires sterilization, for example, with steam at approximately 121 °C. As a non-limiting example, the diaphragm valve V is designed as a manual valve with an actuator and is adjustable by means of a handwheel 6. Alternatively (not shown), the diaphragm valve V can have, for example, a pneumatic actuator instead of the handwheel 6.

[0029] The handwheel 6 is located in Fig. 1 on a housing intermediate piece 1, which is screwed to a housing lower part 2, for example via clamping nuts 8. Pipe stubs 3, 4, here e.g. with a reducing function, lead into the housing lower part 2. The diaphragm valve V contains a diaphragm 5 (shut-off diaphragm), for example made of an elastomeric plastic with or without reinforcement, for example made of EPDM, the functional position of which is better described by Fig. 4 and Fig. As can be seen in Figure 11. In the housing intermediate piece 1, an outlet 7, possibly with a check valve, is indicated as an option to allow pressure equalization to the interior of the drive and, if necessary, to signal leakage.

[0030] According to Fig. 1 and Fig. 2 The diaphragm valve V has four important structural features. First, a pressure sleeve D for tensioning the diaphragm 5 against the lower part of the housing 2 around a valve seat 21 is located in the intermediate housing piece 1 ( Fig. 4) with a predetermined preload force for reliable sealing, but also for automatically compensating for any changes in the settling behavior of the diaphragm 5. Furthermore, a spindle S, designed as a two-part telescopic spindle, is installed between the handwheel 6 and a pressure piece 11 for adjusting a central area of ​​the diaphragm 5 relative to the valve seat 21. A limiting device B for an opening stroke and / or closing stroke is also provided above the housing intermediate piece 1 in the handwheel 6. Finally, a compensation element K is installed in the pressure piece 11, which automatically compensates for any changes in the settling behavior of the diaphragm 5 and transmits force to the diaphragm 5 in the valve seat 21 for reliable sealing. These four features are explained in detail with reference to the further figures.

[0031] The spindle S in Fig. 2 consists of a spindle part 9, which is in Fig. 2 is coupled to the handwheel 6 via a fastening element 12 in a rotationally fixed manner and e.g. in a pipe section 52 ( Fig. 7) the housing intermediate piece 1 is screwable, and a solid spindle part 10, which is screwable into the spindle part 9 and is connected to the pressure piece 11 in a rotationally fixed manner.

[0032] From the limiting device B in Fig. Figure 2 indicates a sleeve-shaped cam 35, which can be screwed onto the spindle part 9 and engages from above with a lower foot part 40 in an annular collar 111 on the top of the housing intermediate piece 1. Fingers 16 are visible on the pressure sleeve D, which engage in pockets 43 provided in the pressure piece 11 to prevent rotation of the pressure piece 11 (see Fig. 9) The pressure sleeve D is secured against rotation in the housing intermediate piece 1, for example by a non-emphasized positive locking engagement.

[0033] Fig. Figure 3 illustrates the design of the pressure sleeve D, which is, for example, made of cast steel or spring steel. Circumferentially separated spring cheeks 15 extend from a ring base 13 with a lower pressure surface 14 to the annular bearing on the diaphragm 5. These cheeks act like bending springs, meaning they are axially rigid but laterally flexible. Each spring cheek 15 has a ramp-like edge 18 at its free end and a locking lug 17 on its outer side. The fingers 16, here four regularly spaced fingers 16, project inwards freely from the ring base 13 and / or the spring cheeks 15 to engage the pressure piece 11.

[0034] Fig. Figure 4 illustrates the pre-tensioned installation position of the pressure sleeve D in the housing intermediate piece 1, specifically in a position where the locking lug 17, acting as an assembly aid, sits in an engagement recess 23 inside the housing intermediate piece 1. The ring base 13 can move in a receptacle 24 in a lower ring flange 19 of the housing intermediate piece 1. The housing intermediate piece 1 has at least an internal circumferential counter-ramp 22 for the chamfered edge regions 18 of the outwardly pre-tensioned spring cheeks 15. The spring cheeks 15 do not rest against the inner wall of the housing intermediate piece 1, but rather generate a force acting on the diaphragm 5 in the adjustment direction 25 of the diaphragm valve V. During operation of the diaphragm valve and when the pressure surface 14 of the ring base 13 rests on the diaphragm 5, the ring base 13 sits slightly higher in the receptacle 24 than in Fig. 4 is shown, so that a force acting in the direction of the arrow (adjustment direction 25) is exerted on the diaphragm 5 and holds it in a tight fit around a valve seat 21 in the lower housing part 2. The pressure sleeve D automatically compensates for the changing settling behavior of the diaphragm 5 (increasing or decreasing thickness) by means of the interaction between the inclined edges 18 and the counter ramp 22 under the bending spring action of the spring cheeks 15 (in Fig. 4 to the left outwards) with adapting relative movements of the ring base 13, essentially the same preload force is always exerted on the membrane 5, regardless of how the strength or consistency of the membrane 5 changes due to settling.

[0035] Membrane 5 is (in Fig. 4 and Fig. 11) is fixed in a receptacle 20 of the ring flange 19 of the housing intermediate piece 1, and clamped externally onto the housing lower part 2, wherein according to Fig. 1. At least the protruding parts of the diaphragm 5 can project outwards from the housing intermediate piece 1. The valve seat 21 between the pipe connections 3, 4 ( Fig. 1) depending on the axial setting position of the pressure piece 11, the central area of ​​the membrane 5 is either closed or opened to a certain extent.

[0036] Fig. Figure 5 illustrates in detail the two-part spindle S of Fig. 2, which are also in Fig. 6 is shown. The spindle S in Fig. 5 has an internal thread 26 in one of its hollow spindle parts 9, for example a right-hand thread, while the other solid spindle part 10, which can be screwed into one of the spindle parts 9, has an opposing external thread 27 (left-hand thread). An external thread is provided on the spindle part 9 for screwing the cam 35 and the spindle part 9 into the pipe section 52. At the upper end of one of the spindle parts 9, there is, for example, a square 29 for rotationally fixed coupling with the handwheel 6. A threaded bore 30 is provided for the detachable fastening element 12, according to Fig. 2 , provided. The other spindle part 10 has a circumferential groove 31 at its lower end, onto which a square 32 is fitted for rotationally fixed coupling with the pressure piece 11 ( Fig. 6) follows, to which a ring flange 33 is attached. Since one spindle part 9 with its external thread 28 can be screwed into the pipe section 52 of the housing intermediate piece 1, a gear effect results for the pressure piece 11, as the helix angles of the opposing threads 26, 27 of the spindle parts 9 and 10 and also of the external thread 28 in the adjustment direction 25 add up and thus, despite self-locking, a significantly increased stroke of the lower spindle part 10 results.

[0037] In Fig. The handwheel 6 has an outer skirt 34 and a separate inner skirt 65 with hanging legs 56 with hooks 57, the function of which can be determined from the Fig. 7 and Fig. Section 8 is explained.

[0038] The printed piece 11 in Fig. 6 has an upper part 58 in which the lower end of the spindle part 10 is received in a rotationally fixed but axially limited manner, namely above a blind bore 59 in the pressure piece 11. A bore 61 is arranged in the bottom 60 of the blind bore 59.

[0039] Based on the Fig. 7 and Fig. Section 8 explains in more detail the limiting device B for the closing stroke and / or the opening stroke. The core component of the limiting device B is the cam 35 ( Fig. 8), which can be screwed onto the external thread 28 of one spindle part 9. According to Fig. 8 The cam 35 in a ring body 38 has an internal thread 37. On the outside of the ring body 38, at least one retaining recess 39 is formed for a driver of the handwheel 6 (not shown in detail). Furthermore, several circumferentially distributed foot sections 40, separated, for example, by windows, extend downwards from the ring body 38. In the illustrated embodiment, lower and upper stroke stops 41, 42 and stops 41', 42', respectively, are formed on these foot sections as radial shoulders.

[0040] According to Fig. 7 the hook 57 of the inner skirt 65 of the handwheel 6 e.g. works together with the upper stroke stop 42 of the cam 35, which e.g. defines the raised position of the handwheel 6 released from the spindle S.

[0041] In Fig. 7, a ring stop 36 is provided inside the ring collar 111, for example in the form of a spring ring or circlip removable from a circumferential groove. This ring stop 36 determines the maximum height of the cam 35 and the handwheel on one spindle part 9, as well as the handwheel 6, whose legs 56 are either stopped on the lower stroke stop 41 or on the upper stroke stop 42 of the cam 35. The lowest position of the cam 35 or the handwheel 6 results from the interaction either between the stop 42' and the upper end of the tube section 52 or between the stop 41' and the top of the housing intermediate piece 1.

[0042] To use or adjust the limiting device B, a predetermined position of the pressure piece 11 is first set using the handwheel 6. Then, the fastening element 12 is loosened, and the handwheel 6 is raised to the stroke stop 42 so that it is released from the square shaft 29. In this loosened position, the handwheel 6 is rotatable relative to the spindle S, but is rotationally fixed to the cam 35. Therefore, by turning the handwheel 6 in the desired direction, the cam 35 is screwed up or down on the spindle S until a desired position of the cam 35 is set, in which the stops 41', 42' or stroke stops 41, 42 act as described.

[0043] The cam 35 could, if only a selectable closing stroke limit is required, be a simple screw ring with only the upper stroke stop 42 (for the hook 57) and the stop 42' (for the pipe section 52) (not shown).

[0044] Fig. Figure 9 illustrates the installation position of the compensation element K in the pressure piece 11, which is coupled to the spindle part 10. A ring spring assembly 47 or disc spring assembly is installed as the compensation element K in the blind bore 59 ( Fig. 10) installed, wherein a sliding disc 48 may be provided between the ring spring assembly 47 and the lower end of the spindle part 10. In the bore 61 in the bottom 60 of the blind bore 59 in the pressure piece 11, a sleeve 44 is arranged such that it is stopped by a shoulder 46 in its lowest position, but is able to rise from this lowest end position into an inner bore 49 of the ring spring assembly 47 (ring or disc springs in a layered arrangement). In a threaded bore 45 of the sleeve 44, for example, a threaded pin 51 ( Fig. 11) screwed into the diaphragm 5 (embedded there), so that when the pressure piece 11 is pulled up and the shoulder 46 hits the bottom 60, the central area of ​​the diaphragm 5 is pulled up with the pressure piece 11 and the valve seat 21 ( Fig. 4) releases to the desired extent.

[0045] To prevent excessive pressure from being applied to the diaphragm 5 by the spindle part 10 in the closed position, for example, if no closing stroke limiter is provided, the ring spring assembly 47 shortens upon reaching a preselected pressure, which is then essentially kept constant. The ring spring assembly 47 also automatically compensates for any changes in the settling behavior of the diaphragm 5 in order to maintain an approximately constant closing pressure in the closed position, regardless of the thickness or consistency of the diaphragm. This is the primary purpose of the compensation element K.

[0046] The design feature of the pressure sleeve D in the housing intermediate piece 1 is advantageous for both manual valves and diaphragm valves with other actuators. The features of the limiting device B, the two-part spindle S, and / or the compensation element K are primarily advantageous for manual valves but can also be used with diaphragm valves that have a different actuator.

[0047] Fig. Figure 11 shows, for example, the square membrane 5 (with holes for housing connecting screws) in its installed position on the lower housing part 2, and the threaded pin 51 embedded, for example, in the center of the membrane (for screwing on the sleeve 44). Fig. 9.

Claims

[1] Diaphragm valve (V), in particular for aseptic processes, with a drive for adjusting a diaphragm (5) made of elastomeric material by means of a pressure piece (11) relative to a valve seat (21), wherein the diaphragm (5) fixed in the edge region is acted upon circumferentially and permanently outside the valve seat (21) by a spring system in a housing intermediate piece (1), characterized by, that in the housing intermediate piece (1) a pressure sleeve (D) is arranged as a spring system which automatically compensates the settling behavior of the diaphragm (5) and is movable in the adjustment direction (25), which comprises a ring base (13) guided in the housing intermediate piece (1) in the adjustment direction (25) with several, preferably four, axially stiff, spring cheeks (15) separated in the circumferential direction and resilient transversely to the adjustment direction (25), which project upwards from the ring base (13) and have ramp-like edge areas (18) at their free ends which bear against counter ramps (22) in the housing intermediate piece (1) under preload. [2] Diaphragm valve according to claim 1, characterized by, that in the diaphragm valve (V) designed as a hand valve, the drive for adjusting the pressure piece (11) contains a two-part spindle (S) that can be actuated by a handwheel (6), the two spindle parts (9, 10) of which can be screwed into each other via opposing self-locking threads (26, 27) by adding the opposing thread pitches. [3] Diaphragm valve according to claim 1, characterized by , that in the diaphragm valve (V) designed as a hand valve an adjustable limiting device (B) for the closing stroke and / or the opening stroke is provided between a handwheel (6) which can be coupled to a spindle (S) and the housing intermediate piece (1). [4] Diaphragm valve according to claim 1, characterized by , that in the pressure piece (11) a compensation element (K) is arranged which acts on the diaphragm (5) via the pressure piece (11) which is adjustable by a spindle (S) and is spring-loaded relative to the spindle (S). [5] Diaphragm valve according to at least one of claims 1-4, characterized by , that the pressure sleeve (D) is made of high-strength cast steel. [6] Diaphragm valve according to any one of the preceding claims, characterized by , that the pressure sleeve (D) is secured against rotation in the housing intermediate piece (1). [7] Diaphragm valve according to any one of claims 1 to 6, characterized by , that the pressure sleeve (D) has an external locking lug (17) on at least one spring cheek (15) which engages movably in a engagement recess (23), preferably a circumferential groove, inside the housing intermediate piece (1) in the adjustment direction (25). [8] Diaphragm valve according to any one of claims 1 to 7, characterized by , that the pressure sleeve (D) has at least one, preferably several circumferentially distributed fingers (16) projecting freely inwards from the ring base (13) and / or the spring cheeks (15), which engage the pressure piece (11) to prevent rotation of the pressure piece (11). [9] Diaphragm valve according to claim 8, characterized by, that the pressure piece (11) has at least one, preferably open at the top and U-shaped, pocket (43) for engagement of a respective finger (16) of the pressure sleeve (D) in the housing intermediate piece (1) to prevent rotation. [10] Diaphragm valve according to claim 2, characterized by , that one spindle part (9), preferably a hollow spindle part with an internal thread (26), can be coupled to the handwheel (6) in a rotationally fixed manner, and that the other spindle part (10), preferably a solid spindle part, can be screwed into the opposite internal thread (26) of one spindle part (9) with an external thread (27) and is coupled to the pressure piece (11) in a rotationally fixed manner. [11] Diaphragm valve according to claim 10, characterized by , that the spindle part (9) rotatably coupled to the handwheel (6) has at least over part of its longitudinal extent an external thread (28) which also engages in an internal thread of a pipe section (52) of the housing intermediate piece (1). [12] Diaphragm valve according to any one of claims 3 to 11, characterized by , that the limiting device (B) for the closing stroke and / or the opening stroke has a sleeve-like cam (35) that can be screwed onto a spindle (S) adjustable by a handwheel (6) and has at least one stop (41, 41', 42, 42'), wherein at least one lower and / or at least one upper stroke stop (41, 42) is provided, and that the cam (35) is coupled to the handwheel (6) in a rotationally fixed manner. [13] Diaphragm valve according to claim 12, characterized by , that the housing intermediate piece (1) carries an upper ring collar (111) which has an inner ring stop (36) which engages in the path of the cam (35), preferably a spring ring or Seeger ring which is removably fixed in a circumferential groove of the ring collar (111). [14] Diaphragm valve according to one of claims 12 or 13 in embodiment with at least one upper stroke stop (42), characterized by, that the handwheel (6) is detachably coupled to the spindle (S) via a fastening element (12) and, after loosening the fastening element (12), can be moved into a released position by pulling it away from the spindle (S) up to the upper stroke stop (42) of the cam (35) and can be rotated relative to the spindle (S) in the released position for screwing the cam (35) onto the spindle (S). [15] Diaphragm valve according to claim 14, characterized by , that the handwheel (6) has an outer skirt (34) extending over the outer collar (111) and either an inner skirt (65) engaging in the collar (111) between the collar (111) and the cam (35) or several circumferentially distributed semi-cylindrical inner skirts (65) with foot parts (56), each for interaction with the upper stroke stops (42) of the cam (35) defining the released position. [16] Diaphragm valve according to claim 12 insofar as it relates to claim 11, characterized by, that the cam (35) on a ring body (38) having an internal thread (37) for screwing onto the external thread (28) of the spindle (S) and an external locking recess (39) for a driver of the handwheel (6) has several circumferentially separated foot parts (40) on which an upper and / or a lower stroke stop (41, 42) is / are provided. [17] Diaphragm valve according to claim 4, characterized by , that the compensation element (K) has a ring spring assembly (47) placed on the bottom of a blind bore (59) of the pressure piece (11), preferably replaceable, preferably with an inner bore (49), and that a sliding disc (48) is arranged between the ring spring assembly (47) and the spindle (S) which is fixed in the pressure piece (11) with axial limited movement. [18] Diaphragm valve according to claim 17, characterized by, that in the bottom (60) of the blind bore (59) of the pressure piece (11) a sleeve (44) with an internal threaded bore (45) for a threaded pin (51) of the diaphragm (5) is arranged to be slid upwards from a predetermined lowest end position parallel to the adjustment direction (25).

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