JPH03505774A - diaphragm valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to fluid valve technology, and more particularly to diaphragm valves.

The invention is particularly applicable to diaphragm valves for use in the field of biotechnology. Yes, I will explain this in particular. However, the present invention has broader applications. It will be appreciated that the invention may be advantageously used in other environments and applications.

Conventional diaphragm valves have two main areas: (i) cyclic life and (ii) There were deficiencies in ease of maintenance and/or replacement.

Cycle life is extremely dependent on the strength of the diaphragm valve, especially the bending strength of the diaphragm are doing. Some conventional valves utilize metal diaphragms for their high strength. there was. We also use elastomeric diaphragms for superior bending and sealing properties. There was also a valve that was used. Composite diaphragm with elastomers of different strengths Some valves used rubber to strengthen elastomeric diaphragms.

Even with continuous improvements in diaphragm valve design, the overall cyclic life of diaphragm valves still remains depends on the strength of The remainder of the valve components still have significant useful life However, it is often necessary to replace worn components, i.e. the diaphragm. . Traditional configurations simply do not adequately address recurring maintenance or replacement issues. Ta. That is, if the valve has to be repaired or replaced, the various left 6 elements space efficient for valves designed to aid in cleaning, replacement and subsequent reassembly Sexuality was limited. Typically, processing lines in fluidic equipment are closely spaced. , or located in close proximity to other equipment or structures. valve is minimum It is compact enough to operate in hard-to-reach locations and only occupies a small amount of space. Must be. Compactness thus allows for easy valve design without compromising valve performance. This is another main requirement for conducting a measurement.

^”LΩ”L! The present invention provides a novel improvement that has a high cycle life and facilitates maintenance and/or replacement. The purpose is to provide diaphragm valves.

According to the invention, a diaphragm valve has a valve body receiving a diaphragm subassembly. ing. A diaphragm is a composite part made by bonding an elastomer to a metal base. It is a material.

According to another aspect of the invention, the diaphragm subassembly receives and receives the actuation stem. It has a closed sleeve. The diaphragm is secured adjacent to one end of this sleeve. The central part is welded to the stem. At the opposite end of the sleeve , an annular closure ring is supported, which receives the intermediate portion of the stem. It has a threaded part for The cap is slid to secure the subassembly to the valve body. The second end of the tube is engaged with the second end of the tube.

According to another aspect of the invention, a guide member is provided to maintain arcuate linear movement of the stem. is interposed between the stem and the sleeve of the subassembly.

According to another aspect of the invention, the valve body has a ring received therein; in the axial direction of the valve in cooperation with a pair of annular members arranged in the valve body and a closing cap. The dimensions are considerably reduced.

According to yet another aspect of the invention, a further aspect of the invention adjusts the actuation stroke of the valve. According to another perspective, a means of limiting the clamping force applied to the diaphragm is incorporated into the actuator structure.

A major advantage of the present invention is the high cyclic life of the valve due to the composite diaphragm assembly.

Another advantage of the present invention is the ease of cleaning or replacement by the diaphragm subassembly. .

Yet another advantage of the present invention is the compact arrangement of the alternative valve arrangement.

Another option is to adjust the actuation stroke or limit the closing force acting on the diaphragm. Further advantages are realized by the actuator structure.

Still other advantages and benefits of the present invention will become apparent upon reading and understanding the detailed description below. It will be clear to business owners.

ward blood Ω solid king five plate The present invention comprises the parts, arrangements of parts, and preferred embodiments described in detail in this specification and illustrated in the accompanying drawings. In preferred embodiments, it takes physical form.

FIG. 1 is a vertical cross-sectional view of the subject novel valve shown in the closed position.

FIG. 2 is an exploded vertical cross-sectional view of the diaphragm subassembly.

FIG. 3 is an enlarged detailed view of the circled area of FIG. 1, particularly showing the adjustment means of the invention. be.

FIG. 4 is a vertical cross-sectional view of another embodiment of the invention.

FIG. 5 is a vertical cross-sectional view of a toggle actuated embodiment with adjustable actuation stroke. Ru.

FIG. 6 is a vertical cross-sectional view of a rotary manual embodiment for limiting diaphragm force.

FIG. 7 is a vertical cross-sectional view of a pneumatic embodiment incorporating multiple pistons.

Detailed explanation of preferred embodiments Referring now to the drawings, which are for the purpose of illustrating preferred embodiments of the invention, (without limitation), the drawings accept a diaphragm subassembly C. A diaphragm valve A with a valve body B is shown.

More specifically, the valve body has an inlet passage 10 and an outlet passage 12, which The passage communicates with the enlarged recess 14. As shown, the inlet and outlet passages are approximately It is arranged horizontally and communicates with a recess arranged diagonally with respect to the horizontal plane. Ru. The intersection of the inlet passage and the bottom wall 18 of the recess constitutes a valve seat 20. suitable In the configuration, the bottom wall is positioned in the central region where the valve seat is raised for reasons that will become more clear later. It has a tapered or partially conical shape. The exit passage is the entrance passage and thus substantially interconnecting the outlet passageway and the recess. Requires a vertically extending passageway section. Positioning the exit passage below the inlet passage This improves drainage performance.

The valve body is a two-part integral structure consisting of a main valve body 24 and a body extension 24'. torso extension has a circumferentially continuous flange 26 extending substantially radially; The screw 26 serves for valving as will be discussed further below. Body extension and valve body are representative Although generally welded together, the valve body and body extension are unitary as one skilled in the art will appreciate. It may be a cast member. A generally radially extending shoulder 30 is defined in the recess of the valve body. being admired. This shoulder is slightly smaller than the valve seat 20 for reasons that will become clearer later. The large dimension extends radially outward from the tapered base wall 18.

Continuing with reference to FIG. 1 and further to FIG. 2, the diaphragm sub-diaphragm 32 , subassembly sleeve 34.2 parts actuation stem 36, guide member 38, annular closure ring. 40, a closure cap 42 and a handle 44. These subassemblies The body components are secured together as a unit to facilitate replacement of the use assembly. It is good to be worn.

The composite diaphragm has a diaphragm 50 made of metal, preferably stainless steel. are doing. The first or top surface of this metal diaphragm is along a central region. It is fixed to the actuation stem 36. For example, the stem and diaphragm are Spot welded.

The second or lower surface 54 of the metal diaphragm is connected to an elastomeric diaphragm 56. is integrally joined to. This diaphragm 56 is made of EP rubber or similar elastomer. Preferably, it is made of Tomer material. By integrally joining these individual diaphragms , the strength is greatly increased and still retains the sealing properties of the elastomeric part. A composite diaphragm assembly is obtained.

The subassembly sleeve 34 has an outer circumferential dimension that generally approximates the inner diameter of the valve body recess.

This aligns the subassembly to the valve body and provides a stabilizing interference fit. Can be done. A bore 60 snugly receives the actuating stem through the sleeve. Three The first or lower end 62 of the stem includes a counterbore for receiving the enlarged end of the actuating stem. A bore 64 is provided. The radial shoulder defined by this counterbore is As one skilled in the art will appreciate, it can be used as a valve stopper to limit the opening movement of a diaphragm valve. Function. A second counterbore 66 extends from the second or upper end 68 of the sleeve. Extending radially inward. This second counterbore has a guide or bushing section. The material 38 is received snugly.

The bushing member is attached to the actuating stem to ensure smooth linear movement of the actuating stem. The first or lower portion 74 generally receives the lower end of the second portion 78 of the stem. It has a groove 76 in the shape of an inverted letter. In detail, the approximately spherical nozzle of the second part of the stem The stem 80 abuts and engages the lower portion of the stem to allow the stem to slide without transmitting torque from the handle 44. Press the stem and diaphragm into the closed position with the valve seat 20. adjacent to the nose A radial shoulder 82 defined by the diameter cooperates with the reduced diameter portion of the T-shaped groove during the valve opening movement. to push the lower portion of the stem and diaphragm away from the valve seat.

The stem is externally threaded at 86 to cooperate with the internally threaded region 88 of the closure ring 40. ing. Rotation imparted to the actuating stem causes the stem to close with a ring and sleeve The valve is opened and closed by advancing and retracting the valve in a manner well known in the art. closed The chain ring is now fit and received in the second counterbore 66 of the sleeve. It has a reduced diameter portion 90 extending in the radial direction. This allows the lower portion 74 of the stem to This facilitates reliable positioning of the second portion of the stem relative to the stem. Additionally, the closure ring between the cap 42 and the subassembly sleeve to axially secure the subassembly to the subassembly. A radially extending flange 92 is sandwiched and received in between.

The cap 42 also includes a radially extending portion that abuts and engages the upper end of the housing. It has 98. A radially inner portion 100 overlies the flange 92 of the closure ring. The radially outer portion 102 cooperates with the flange 26 of the barrel extension. sub-assembly The means for securing the body to the valve body consists of a series of fasteners 106, these The fasteners are arranged circumferentially around the valve and are attached to the barrel extension and the flange 2 of the cap. 6.102 are interconnected.

Handle 44 is secured to the upper portion of stem 48 by set screw 108. . Due to this connection, the valve seat 20 moves toward or away from the valve seat 20 as described above. Effectively rotate the handle for reciprocating motion of the diaphragm in the direction of the actuating stem can be transmitted.

From the handle, an integral sleeve 110 extends axially in a surrounding relationship with the closure ring 40. Extends downward. This sleeve 110 prevents chips and debris from entering the closure ring. serves the protective function of restricting the screws from entering and disturbing the threaded area 86.88 .

The subassembly shown in FIG. 2 can be easily inserted into the recess 14 of the valve body. Three The tabs 34 and recess shoulders 30 tightly engage the circumferential portion of the composite diaphragm.

This clamping configuration defines a first sealing area of the diaphragm valve. actuation stem A support or second sealing member 120 is interposed between the sleeve and the sleeve.

As is clear from the rotation of the handle, the central part of the stem and composite diaphragm axially advance or retreat toward or away from the valve seat. Let me do it. This structural configuration features a diaphragm to ensure precise opening and closing position. Make sure the ram moves forward and backward.

As mentioned above, this subassembly configuration aids in diaphragm maintenance and replacement. . In particular, the valve body remains fixed to the fluid system, but the diaphragm subassembly It is easy to remove and insert. Due to tolerance changes, the stem relative to the valve seat 20 It is important that some play remains in the subassemblies to direct movement. good Preferably, the axis of the actuating stem should be aligned so that the composite diaphragm is evenly seated on the valve seat. Directional movement is precisely aligned with the center of the inlet passage. Closed, as shown in detail in Figure 3. A radial gap 122 is defined between the ring 40 and the cap 42. Ru. This clearance allows the axis of the actuating stem to align with the valve seat before final tightening of the fastener. Slightly radially or laterally rotate the closure ring so that it is precisely aligned with the Can be adjusted.

Referring to FIG. 4, another configuration of a diaphragm valve is shown.

For the sake of simplicity and ease of understanding with respect to the embodiments of FIGS. 1 to 3. , using similar terminology wherever possible to refer to the elements of the different diaphragm valves A'. valve The barrel B' has an inlet 210 which is connected to an outlet 212 via a recess 214. Communicate selectively. A valve seat 220 is defined at the intersection of the inlet and the recess; Inlets, outlets, recesses and valves as described for the embodiments of FIGS. 1-3. The seat is configured to enhance drainage of the valve.

A continuous shoulder 230 is defined in the recess, which shoulder is connected to the composite diaphragm 23. It is designed to accept the circumferential portion of 2. The composite diaphragm has gills facing the valve seat. A first layer 234 of stroma material is included. The second layer 236 preferably has strength and Metal material for durability and durability. The first and second layers are bonded to each other and unified. It makes up the body structure.

According to this embodiment, the second metal layer is first secured to the lower end 240 of the two-piece actuation stem. It will be worn. Preferably the metal layer is welded to the lower end of the stem, but within the scope and scope of the invention. It is recognized that other anchoring structures can be used without departing from the There will be. A first layer of elastomer 234 is then bonded together to the first layer.

As is evident in Figure 4, the metal layer of the composite diaphragm is made of elastomeric material. The plug 242 is annularly shaped to receive the plug 242. extending from the layer through the second layer of the diaphragm into the cavity in the lower end portion of the stem. .

The recess receives a sleeve or first annular member 250, which member The composite diaphragm is tightly engaged against the shoulder 230 along the circumferential portion.

This annular member is sized to fit snugly into the recess, and is Although it is comparable to the sleeve of the above embodiment in this respect, the axial dimension is considerably reduced. ing. Specifically, the annular member is disc-shaped, and the axial direction 252 is the disc shape. Extending outward from one side. This annular member is a bollard that receives the lower end of the stem. It has a through opening 254. The rebore 256 that ends from this bore is the shaft. Extending linearly inwardly, this counterbore 256 has a stem that limits release movement of the stem. It defines a radial shoulder that acts as a topper.

A groove 262 defined in the recess in a region located axially outwardly from the shoulder 230 A retaining ring 260 is a snap fit. This ring has a very compact structure. A fixed mounting area for holding the valve components fixed to the valve body in the There is. Between the ring 260 and the annular member 250, there is a third ring also called a crumbling ring. Two annular members 264 are axially positioned. However, it becomes clear later In order to adjust the tightening force acting on the diaphragm, the first ring is A gap 266 is defined between the annular member and the second annular member. Second annular member are circumferentially spaced threaded openings adapted to receive fasteners 270; It has 268.

The fastener extends from the threaded engagement with the second annular member through the central opening of the ring 260. It is extending. The outermost end of the fastener applies the clamping force to the closing cap or bong. Expanded to convey to the internet.

In fact, the enlarged end of the fastener in order to transfer the tightening force more effectively to the closing cap It is preferable to interpose a support ring under the section.

The closure cap has a central opening 284 that receives the stem. For details, The lower end 240 of the stem is guided for axial reciprocating movement within this opening.

The rotational motion imparted to the stem via the handle 280 is applied to the actuating stem and the dial. The upper end 276 of the two-piece stem has an opening for converting axial movement of the flam. It is threadedly engaged with the female threaded region 278 of. from the top end of the stem to the bottom end of the stem. The means for limiting torque transmission are as described above with respect to the embodiments of FIGS. 1 to 3. Since it is the same as that shown in Figure 4, there is no need to further explain the configuration in Figure 4. It seems to be that.

The closure cap has an axially extending nose portion 292, which 1 abuttingly engages the axially extending portion 252 of the annular member.

This transmits the tightening force to the first annular member, especially its circumferential portion, and creates a composite diaphragm. Tighten the ram to shoulder 230. Thus, in summary, the fastener is connected to the second annular member. Tighten against. The force acting on the second annular member is caused by the ring 260 passing through the groove. Resistance is provided by this ring 260 due to its fixed engagement with the valve body. The fastener is , transmits these forces to the closure cap, which in turn transfers the clamping force to the first The signal is transmitted to the annular member.

The O-ring 294 is radially interposed between the lower portion of the stem and the first annular member. A second support seal is configured. As mentioned above, the diaphragm In addition to adjusting the communication with the mouth, it also constitutes the first seal for the valve. It's a closed cap. A wiper ring 286 is disposed axially outward of the wiper region 278. This wai The palling keeps the cap closed with thread lubricant and keeps dust and particulate matter out. Limit ingress into the valve from the side environment.

To facilitate stem alignment, the cap and barrel are marked with reference numeral 290 during closure. and a consultation positioning surface shown. These locating surfaces allow the closure cap to and more importantly, the outer end of the stem can be aligned against the valve seat. .

This alternative embodiment retains all the advantages of FIGS. 1-3, and in addition has its own It has advantages. Among the improvements, the alternative embodiment of Figure 4 is much more compact. be. Eliminates external mounting of bolts, thereby reducing the overall radius of the valve structure . Also, as a result of the internal means for transmitting the clamping force to the diaphragm, the axis of the valve The directional dimension is reduced. Additionally, this structure requires diaphragm manufacturing and Assembly becomes considerably easier.

Three alternative actuator structures are shown in FIGS. 5-7. these Each of the embodiments has the same valve body, diaphragm, and as detailed above with respect to FIG. having a structure of first and second annular members, a retaining ring and a closure cap. . Therefore, there is no need to further describe these similar structures. deer However, these separate actuator structures are A manually actuated handle affixed to the top portion provides several advantages that are not present.

For example, with reference to FIG. 5, means 3 for adjusting the working stroke of the stem. 00 is shown. This adjustment means 300 is used to control the closure cap or bonnet. It has an elongated extension 302, which is indicated by the numeral 304. It is externally threaded along its outer edge. The stroke adjustment member 310 It is internally threaded to cooperate with the threaded extension of the top. These cooperating threads axially relative to the closure cap by selectively rotating member 310. It can be moved in the direction. In addition, the predetermined axial position of the stroke adjustment member A locking member is threaded onto the extension of the closure cap to maintain the closure cap. Furthermore, adjustment Both the member and the locking member are preferably configured to facilitate their rotation. Each has a tool engaging surface or wrench flat 314,316.

A generally flat end surface 320 of the adjustment member abuts one end 322 of a toggle handle 324. match. Toggle handle selective position of toggle handle between open and closed positions It is secured to the upper portion of the actuating stem by a pin member 326 for determining purposes. (i ) between the surface 328 of the toggle handle and the pin; and (ii) of the toggle handle. Without changing the distance between surface 330 and the bottle to advance or retract the actuating stem. As this is generally well known, further information is provided for a full and complete understanding of the present invention. It seems unnecessary to explain.

Additionally, the upper portion of the stem is modified by providing a radially extending flange 340. will be changed. A first end of a biasing means, such as a spring 344, is supported on the flange. It is. The second end 346 of this spring is connected to the inner shoulder 348 of the closure cap extension. is engaged in. This spring structure keeps the actuation stem and diaphragm in a normally closed position. It is biased towards the position. By rotating the toggle handle to the virtual position shown in Figure 5, The diaphragm can be lifted off the valve seat to allow fluid to flow from the inlet to the outlet.

Also, a bonnet extension to maintain stability and alignment of the upper part of the stem. A guide member 350 is provided in the section.

Rotation of the adjustment member changes the position of the end face 320 relative to the valve body.

Due to total manufacturing tolerances, e.g. slightly changing the position of the stem in the open position Sometimes. The adjustment member is thus adapted to compensate for this problem.

In other words, the diaphragm valve reaches the imaginary fully upright position of the toggle handle. The fully open position is only achieved when the Example of Figure 4 As mentioned above, the radial shoulder of the annular member restricts the opening movement of the stem. It constitutes a stopper that limits the However, due to the total tolerance problem, the stopper The toggle handle must reach the fully actuated position, i.e. the fully upright position, before the Resulting in. Thus, the distance between the bottom surface of the diaphragm and the valve seat is less than ideal. Ru. On the other hand, the toggle handle encounters the stopper before reaching the fully open position. . By rotating the adjustment member, the operator can restrain the stopper from fully opening the toggle handle. can be precisely matched. Once adjusted, the engagement member 312 is in the adjusted position. maintain.

Referring to FIG. 6, a predetermined rotation of handle 360 causes the actuation assembly to Activate manually. For ease of illustration and comparison with the embodiment of FIG. Different elements are indicated by the same number with a dash (′), and new elements are indicated by new numbers. vinegar. The handle cooperates with an externally threaded area 304' on the bonnet extension 302'. Therefore, it has a female thread. At the outer end of the actuation stem is a retaining member 362, a retaining ring. A thrust washer 364 and a thrust washer 366 are supported, and these members are is interposed between the stem and the handle. The retaining member is a radial flange 368 The flange has one side attached to the inside shoulder 370 of the handle and the other side attached to the inside shoulder 370 of the handle. side abuttingly engages the thrust washer. Also, the thrust washer is sleeve 38. 2, the second enlarged end of the sleeve is engaged with the first end 380 of the sleeve, and the second enlarged end of the sleeve is connected to the spring end 346'. engage with.

In this structural configuration, axial movement of the handle is controlled by sleeve 382 and spring 3. 44' to the diaphragm. Additionally, the thrust washer is closed. , a stop surface 39 defined in the bonnet extension before the spring is fully compressed. 0. This results in excessive rotation of the handle. The degree of closing force will not encounter the diaphragm, thus destroying it. limiting possibilities. In the fully closed position, only the biasing force of the spring is transmitted to the diaphragm It is only done.

In the specific example of the actuator in Figure 7, similar parts are marked with a double dash ('). The same number indicates the same number, and new elements are indicated with new numbers.

In this modification, a fluid-actuated, specifically air-actuated, diaphragm valve is shown. , the pressure required to operate this diaphragm valve is lower. Than In particular, the outer end of the bonnet extension 302' includes an actuator housing. 400 is supported.

The actuation stem is modified to receive the first and second pistons 402,404. These pistons are secured by retaining rings 406 and nuts 408. It is fixed by a fastening means. Each of the pistons has an O-ring like 410.412 These O-rings 410 and 412 are attached to the housing. Together, they constitute the first and second pressure bodies 420 and 422. These pressure chambers The split member 424 is secured to the housing through the use of a snap ring 426. It is separated. This dividing member is sealed to the second pressure chamber by an O-ring 428. They engage and define a circumferential passageway 430 with the first pressure chamber. Also, the dividing member is in the center The actuating stem is received through the opening 432, thus creating a gap between the first and second chambers. An additional O-ring 434 is required to maintain the sealing relationship.

The inlet passage 440 connects first and second branch passages that supply pressurized air to the first and second chambers. 442 and 444. Thus, the air inlet applies pressure to the piston 402. 404 to press the diaphragm toward the open position. a pair of pices Due to the increased surface area provided by the two pistons, it is easier to open the valve. The air pressure required is reduced. This reduced air pressure also affects the valve actuator. This is advantageously achieved without unnecessarily enlarging the data.

The invention has been described in terms of preferred embodiments. Clearly, this specification has been read and understood. Modifications and variations may then occur.

All such modifications and variations are included within the scope of the appended claims or their equivalents. It is encompassed by the present invention to the extent that

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Claims (27)

[Claims] 1. a body having an inlet and an outlet in operative communication across the valve seat; a circumferentially continuous shoulder defined in said torso; and a circumferentially continuous shoulder defined in said torso; a composite diaphragm that is tightly engaged with the part; snugly received in said valve body and attached to said diaphragm against said shoulder; an annular member having a first end secured to the diaphragm and a second end engaging the diaphragm; an actuation stem with an end extending outwardly through the annular member and adapted to close the recess; The closing cap is axially received in the recess between the annular member and the closing cap. The inserted ring and means for axially transmitting force from the ring to the annular member. A diaphragm valve characterized by: 2. The force transmitting means includes a second annular member disposed axially between the annular member and the ring. The diaphragm valve according to claim 1, further comprising a member. 3. Claims characterized in that the second annular member operatively engages an inner surface of the ring. The diaphragm valve according to item 2. 4. The force transmitting means includes an adjustable clasp extending between the second annular member and the closure cap. 4. The diaphragm valve according to claim 3, further comprising a fitting. 5. The force transmitting means extends from the second annular member through the ring to the closure cap. Diaphragm according to claim 3, characterized in that it has a possible fastening device. Ram valve. 6. further comprising means for limiting torque transmission along the actuation stem. The diaphragm valve according to claim 1, characterized in that: 7. The torque limiting means is interposed between the first end and the second end of the stem, and the torque limiting means is interposed between the first end and the second end of the stem. The first end of the stem is adapted for both rotation and axial movement, and the second end is adapted for axial movement. Claim 6, characterized in that the device is adapted to move only in a direction. diaphragm valve. 8. further comprising support sealing means interposed between the actuation stem and the annular member. The diaphragm valve according to claim 1, characterized in that: 9. A composite diaphragm faces the valve seat and is used to selectively open and close communication between the inlet and outlet. The dazzling material according to claim 1, characterized in that it has an elastomer layer of Earphragm valve. 10. a body having an inlet and an outlet in selective communication across the valve seat; Received in the recess so that it can be selectively moved towards or away from the valve seat A composite diaphragm is placed along the rear surface of the diaphragm. a first annular member sealingly clamping the circumferential portion of the ram to the barrel; a closure cap that is partially received and engages the first annular member; an actuation stem extending through the closure cap, the stem being connected to the diaphragm. The first end is fixed to this diaphragm without passing through, and the stem is attached to the closing cap. a second end that cooperates with the closure cap for advancement and retraction relative to the pool; a region disposed axially between the first annular member and the closure cap; A ring fixed to the torso in the area, a second annular member interposed in the axial direction between the ring and the first annular member; The second annular member transmits the tightening force from the body to the second annular member through the ring. the second annular member abuttingly engages the ring, and transfers the tightening force from the second annular member to the second annular member. 1 means for transmitting to the annular member and the closure cap transmitting to the diaphragm; A diaphragm valve comprising: 11. Further comprising a second seal member supported on the outer periphery of the stem. A diaphragm valve according to claim 10. 12. The tightening force transmission means is from the second annular member through the ring to the closure cap. 11. A diamond according to claim 10, characterized in that it has an extending fastener. Flam valve. 13. Defined in the body for linear movement of the closing cap and actuating stem at right angles to the valve seat Claim further comprising a locating surface for enabling alignment. The diaphragm valve according to item 10. 14. to limit the transmission of torque from the second end of the stem to the first end of the stem; A diaphragm according to claim 10, further comprising means of valve. 15. a body having an inlet and an outlet in operative communication across the valve seat; a composite diaphragm received in and tighteningly engaged with the body; a first end secured to the diaphragm and a second end extending outwardly from the body. an actuation stem; means for biasing the actuation stem toward one of the open and closed positions; and, means for moving the actuation stem toward the other of the open and closed positions; and, and means for changing the stroke of the actuation stem. diaphragm valve. 16. The modification means includes a bonnet extending from the valve body and operatively associated with the bonnet. a handle connected to the operating stem, and a handle interposed between the handle and the bonnet. movement of the handle relative to the valve body changes the stroke of the actuating stem. It has an adjustment member that can be adjusted in the axial direction with respect to the bonnet. A diaphragm valve according to claim 15. 17. Further means for limiting the degree of axial adjustment of the handle relative to the valve body. 17. The diaphragm valve according to claim 16, characterized in that the diaphragm valve is provided with: 18. The changing means shall have a means for locking it to prevent it from being adjusted. The diaphragm valve according to claim 16, characterized in that: 19. The locking means is supported by the bonnet and adapted to abuttingly engage the modification means. Claim 18, characterized in that it is constituted by a double threaded member. diaphragm valve. 20. The biasing means includes a spring interposed between the actuation stem and the bonnet. The diaphragm valve according to claim 15, characterized in that: 21. The means of movement consists of a toggle handle located at one end of the actuation stem. The diaphragm valve according to claim 15, characterized in that: 22. a body having an inlet and an outlet in the chamber communicating across the valve seat, and a body receiving the body; the valve seat and move it toward or away from the valve seat to adjust the flow between the inlet and outlet. a diaphragm that selectively moves in the direction of A bonnet that cooperates with the body to close the valve chamber and an actuating stem in open and closed positions. means for biasing toward one of the positions; and means for limiting the compressive closing force acting on the diaphragm. Features a diaphragm valve. 23. The restriction means includes a sleeve disposed around the actuating stem, the sleeve being The rib has a first end operatively engaged with an actuation member secured to the actuation stem and a biasing end. the biasing means has a second end operatively engaged with one end of the biasing means; 23. The diaphragm valve of claim 22, wherein the diaphragm valve engages a stem. 24. The actuation stem is characterized in that it can freely rotate relative to the actuation member. The diaphragm valve according to claim 23. 25. configured in the bonnet to permit axial closing movement of the actuating member relative to the bonnet. Claim 23, further comprising a limiting stopper. diaphragm valve. 26. The stopper is activated before the biasing means constituted by a spring is completely compressed. The diamond according to claim 25, characterized in that the closing movement of the stem is restricted. Flam valve. 27. A second stop is further provided for limiting axial outward movement of the actuation stem. 27. The diaphragm valve according to claim 26, characterized in that the diaphragm valve has: