JPH09196200A - Diaphragm valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably improve the sealing performance against the leakage of the fluid outside a valve body in a diaphragm valve excellent in the wear resistance to be used in the transport piping line of various fluids. SOLUTION: A diaphragm valve comprises a fluororesin sheet 8 lined by a rubberlike elastic body 6, and a circumferential edge projected bar 7 for pressing is provided on the position of a back surface side 16 of the fluororesin sheet 8 opposite to a circumferential edge projected bar 10 for sealing provided on the liquid-contact surface side 15 of the fluororesin sheet 8 is provided. When the fluororesin sheet 8 is tightened between a bonnet 11 and a valve body 1 by bolts and nuts, the circumferential edge projected bar 7 for pressing presses the circumferential edge projected bar 10, and reduction of the contact pressure of the circumferential edge projected bar 10 with a flange surface 5 is suppressed to prevent projection and flattening of the circumferential edge projected bar 10 to the back surface side 16, and the sealability of the diaphragm valve can be kept.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm valve used in a pipeline for transporting various fluids (chemical solutions such as water and hydrochloric acid, and slurry). More specifically, the present invention relates to a diaphragm valve having excellent corrosion resistance and outside the valve body. The present invention relates to a diaphragm valve having significantly improved sealing performance against fluid leakage.

[0002]

2. Description of the Related Art Conventionally, a diaphragm valve has been constructed such that a diaphragm made of a fluororesin sheet lined with a rubber-like elastic body is pressed against or separated from a partition wall provided in the center of the main body and having a curved flow path. It is a valve that opens and closes a passage, and is widely used in transportation pipelines for various fluids due to its relatively simple structure and reliable fluid shutoff. To improve its sealing performance, a fluororesin sheet is used. A sealing ridge is provided at a portion of the valve body that comes into contact with the flange portion or the partition wall to prevent fluid leakage to the outside of the valve body.

[0003]

However, in the above-mentioned conventional sealing structure for a diaphragm valve, the bonnet, the diaphragm made of a fluororesin sheet lined with a rubber-like elastic body, and the tightening of the bolts and nuts for sandwiching the valve body 3 are involved. Due to such factors, among the sealing ridges provided on the liquid contact surface side of the fluororesin sheet during long-term use, particularly the peripheral ridges are flattened, or most of them are projected to the back surface side, so that the diaphragm The sealing performance of the valve will drop significantly. Therefore, even if the fluid pressure is low, leakage will occur. Especially, when corrosive fluid (eg hydrochloric acid, concentrated sulfuric acid, hypochlorous acid, etc.) leaks to the outside of the valve, the bolt used. Corrosion of nuts and other metals could result in personal injury.

The present invention has been made in view of the above-mentioned conventional techniques, and an object thereof is to provide a diaphragm valve having excellent corrosion resistance and having significantly improved sealing performance against fluid leakage to the outside of the valve body. To do.

[0005]

The structure of the present invention as a means for solving the above problems will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. The diaphragm valve of the present invention has an inlet port. A valve body 1 having a flow path 2 and an outlet flow path 3 and a partition wall 4 located between these flow paths and having a curved flow path, a bonnet 11 attached to the valve body 1, and a bonnet. Spindle 12 supported on 11
It is sandwiched between the compressor 13 fixed to the lower end of the valve body 1 and the valve body 1 and the bonnet 11, and is fixed to the compressor 13 to be pressed against and separated from the partition wall 4 to block the flow of fluid. And a diaphragm to be passed through, the diaphragm is made of a sheet 8 of a corrosion resistant material lined with a rubber-like elastic body 6, and the sheet 8 of the corrosion resistant material has a liquid contact surface side 15 thereof. A peripheral ridge 10 for sealing and a linear ridge 9 abutting the partition wall 4 are provided, and a peripheral rim for pressing is located at least at a position on the rear surface side 16 of the sheet 8 of the corrosion resistant material facing the peripheral ridge 10 for sealing. It is characterized in that the ridge 7 is provided.

According to a preferred embodiment of the present invention, the rubber-like elastic body 6 is made of ethylene propylene diene terpolymer (EPDM), and the sheet 8 of the corrosion resistant material is made of fluororesin.

Further, the pressing peripheral ridges 7 can be provided in double, and the sectional shape of the pressing peripheral ridges 7 can be any of a semicircle, a rectangle, a trapezoid and the like.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings, but it goes without saying that the present invention is not limited to the embodiments. 1 is a longitudinal sectional view of a diaphragm valve made of vinyl chloride resin showing an open state, FIG. 2 is a sectional view of the fluororesin sheet in FIG. 1, FIG. 3 is a rear surface side plan view of the fluororesin sheet in FIG. 2, and FIG. FIG. 3 is a plan view of the fluororesin sheet in FIG.

In FIG. 1, reference numeral 1 denotes a valve body of a diaphragm valve, which has an inlet flow passage 2 and an outlet flow passage 3, and a gentle arcuate shape in which the flow passage is curved in the middle of these two flow passages. It has a partition wall 4 having a curved surface. A compressor 13 is fixed to the lower end of the spindle 12. 8 is a rubber-like elastic body 6, for example, a corrosion-resistant material lined with ethylene propylene diene terpolymer (EPDM), for example, a fluororesin sheet (PTFE, etc.)
At the portion fixed to the compressor 13 and in contact with the partition wall 4 of the valve body 1 and the flange surface 5 of the valve body 1, the sealing linear projection 9 and the peripheral projection 1 continuous with the sealing linear projection 9 are formed.
0 is integrally provided (FIG. 4). Reference numeral 7 denotes a pressing peripheral ridge, which is provided at a position on the back surface side of the fluororesin sheet 8 so as to face the peripheral ridge 10 provided on the liquid contact surface side 15 of the fluororesin sheet 8. In this embodiment, only the pressing peripheral ridge 7 is provided, but in addition to this, a pressing linear ridge may be provided at a position opposite to the sealing linear ridge 9. Incidentally, the height of the pressing peripheral projection 7 is preferably set to about 0.8 mm to 2.0 mm. Moreover, the cross-sectional shape may be any shape such as a semicircular shape, a rectangular shape, or a trapezoidal shape.

In this embodiment, the peripheral edge ridge 10 on the liquid contact surface side 15 is provided only once, but may be provided twice. In that case, it is better to double the pressing peripheral edge ridges 7 on the back surface side 16.

Next, the operation of the diaphragm valve of this embodiment will be described with reference to FIG. When closing the flow paths 2 and 3, the handle 14 is rotated. Then, the rotation of the handle 14 causes the spindle 12 to descend and the compressor 13 to descend. When the compressor 13 descends, the compressor 13 presses the fluororesin sheet 8 lined with the rubber-like elastic body 6.
When the compressor 13 presses the fluororesin sheet 8, the partition wall 4 of the valve body 1 presses the fluororesin sheet 8 to close the flow paths 2 and 3, and the valve is closed.

On the other hand, in order to shift from the closed state to the open state, the handle 14 is rotated in the direction opposite to the closing operation of the flow paths 2 and 3. Then, the rotation of the handle 14 raises the spindle 12 and the compressor 13 as well. When the compressor 13 rises,
The compressor 13 pulls up the fluororesin sheet 8 lined with the rubber-like elastic body 6. Then, the fluororesin sheet 8 is separated from the partition wall 4, the flow paths 2 and 3 are opened, and the valve is opened.

Further, peripheral edge projections 10 provided on the liquid contact surface side 15 and the rear surface side 16 of the fluororesin sheet 8 sandwiched between the bonnet 11 and the valve body 1 by tightening bolts and nuts, etc. The pressing ridges 7 are supported by each other's force, that is, the pressing ridges 7 are the peripheral ridges 1.
By pressing 0, the peripheral edge ridge 10 is prevented from projecting to the back surface side and the peripheral edge ridge 10 being flattened on the liquid contact surface side. Therefore, since the reduction of the contact pressure between the peripheral edge ridge 10 and the flange surface 5 of the valve body 1 is suppressed, the initial sealing pressure of the peripheral edge ridge 10 is maintained.

Therefore, the sealing performance of the diaphragm valve can be maintained, and the leakage of fluid from the valve body can be prevented for a long period of time.

Here, the above embodiment of the present invention and a conventional diaphragm valve (comparative example) incorporating a fluororesin sheet lined with a rubber-like elastic body having no pressing ridges on the back side are incorporated. , For each of the caliber 50A, the bolt tightening torque holding the valve body, the fluorocarbon resin sheet lined with a rubber-like elastic body and the bonnet is changed, and when the fluorocarbon resin sheet is fully opened, A pressure test with water was performed. That is, a seal test between the fluororesin sheet and the valve body,
A leak test from the valve was conducted to examine under which water pressure the present invention and the comparative example leak. The valves used each had four fastening bolts.

Test method: The outlet flow path of the valve is closed, the valve in the fully opened state is filled with water from the inlet flow path to increase the water pressure, and the water pressure when the valve leaks is recorded. . Sample: Diaphragm valve diameter 50 mm Both the valve body and bonnet are made of polypropylene (PP) Water temperature: 18 ° C Table 1 shows the results.

[0017]

[Table 1]

From Table 1, it can be seen that the diaphragm valve of the present invention has significantly better sealing performance than the conventional product.

[0019]

Since the diaphragm valve of the present invention has the structure and operation as described above, the sealing performance thereof is significantly improved as compared with the conventional diaphragm valve using the fluororesin sheet. . It is particularly effective for diaphragm valves used in corrosive fluid transportation piping lines, prevents corrosive fluid from leaking out of the valve body, prevents peripheral equipment from corroding and causing personal injury, and improves worker safety. Can be secured.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the fluororesin sheet in FIG.

3 is a rear surface side plan view of the fluororesin sheet in FIG. 2. FIG.

FIG. 4 is a plan view of the fluororesin sheet in FIG. 2 on the liquid contact surface side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Valve main body 2 ... Inlet flow passage 3 ... Outlet flow passage 4 ... Partition wall 5 ... Valve main body flange surface 6 ... Rubber-like elastic body 7 ... Pressing ridge 8 ... Fluorine resin sheet 9 ... Linear ridge 10 ... Perimeter Protrusions 11 ... Bonnet 12 ... Spindle 13 ... Compressor 14 ... Handle 15 ... Liquid contact side 16 ... Back side

Claims (5)

[Claims] 1. A valve body having an inlet channel, an outlet channel, and a partition wall located between these channels and bending the channel, a bonnet attached to the valve body, and a bonnet. A compressor fixed to the lower end of the spindle supported by the, and a diaphragm fixed to the compressor and sandwiched between the valve body and the bonnet to be pressed against and separated from the partition wall to block and pass the flow of fluid. In a diaphragm valve equipped with
The diaphragm is made of a sheet of a corrosion resistant material lined with a rubber-like elastic material, and a peripheral ridge for sealing and a linear ridge that abuts on the partition wall are provided on the liquid contact surface side of the sheet of the corrosion resistant material. A diaphragm valve, wherein a pressing peripheral ridge is provided at a position facing at least the peripheral ridge on the back surface side of the sheet of the corrosion resistant material. 2. The diaphragm valve according to claim 1, wherein the rubber-like elastic body is ethylene propylene diene terpolymer, and the corrosion-resistant material is a fluororesin. 3. The diaphragm valve according to claim 1, wherein the sealing peripheral ridge is sandwiched between the bonnet and the valve body flange surface. 4. The diaphragm valve according to claim 1, wherein each of the sealing peripheral ridge and the pressing peripheral ridge is provided in double. 5. The diaphragm valve according to claim 1, wherein the cross-sectional shape of the sealing peripheral projection is semicircular, rectangular, or trapezoidal.