Method for manufacturing a diaphragm valve

Abstract

To provide a diaphragm valve manufacturing method capable of reducing an aging variation of a flow rate and an influence on durability.SOLUTION: A diaphragm valve comprises: a body which has a valve chamber with an opening on an upper face thereof and fluid inflow and fluid outflow passages, respectively open on a bottom face of the valve chamber, installed in the body; an annular seat arranged around an opening of the fluid inflow passage on the bottom face of the valve chamber; a diaphragm which seals the valve chamber and opens and closes the fluid inflow passage with the same elastically deformed to come in contact with or move away from the seat; and a diaphragm operation section which has a tip section pressing the diaphragm so that the same is elastically deformed to come in contact with or move away from the seat. A manufacturing method for the diaphragm valve comprises: a step d1 to adjust an uplift amount of the tip section of the diaphragm operation section to a prescribed amount when moving away upon pressing and a step d2 to break in the diaphragm to come into contact with and move away from the seat predetermined times by the diaphragm operation section.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a diaphragm valve.

Background Art

[0002] A direct diaphragm valve (hereinafter also simply referred to as a "diaphragm valve") is used for ON / OFF control of process gases for semiconductor manufacturing (for example, Patent Document 1). A diaphragm valve is a valve that controls the flow path of a fluid to open / close and the flow / stop of the fluid by pressing a diaphragm with an opening / closing operation mechanism using an air cylinder, and separating / bringing into close contact between the diaphragm and a valve seat. Since the fluid to be controlled is completely isolated from the opening / closing operation mechanism by the diaphragm, the diaphragm valve has advantages such as less leakage and contamination. As this valve seat (hereinafter referred to as "seat"), a resin material such as PTFE having appropriate flexibility and high sealing performance in the closed state is used. When a seat made of such a resin material is repeatedly abutted against the diaphragm by opening and closing after the start of use, it gradually collapses. As a result, there has been a problem that the gap between the seat and the diaphragm in the open state gradually increases, and the Cv value, which is an index of ease of flow, increases. To address this problem, a method has been proposed in which aging (running-in operation) is performed by repeatedly performing the opening / closing operation during the manufacturing adjustment of the diaphragm valve to finish the shape change of the seat due to opening / closing, and then adjusting the gap between the seat and the diaphragm to a predetermined value so that such a change does not occur after delivery to the customer (Patent Document 2).

[0003] As such an aging method, Patent Document 2 describes performing opening and closing a predetermined number of times at a predetermined temperature (for example, 200°C). Specifically, in the case of a diaphragm with an outer diameter of 26 mm, opening and closing aging is performed 3,000 to 10,000 times at full stroke (for example, a lift amount ΔS of 1.2 mm), and then the lift amount is adjusted to 55 to 70% of the full stroke (for example, 0.7 mm) and used. As a result, the shape change of the resin valve seat during actual use is reduced, the Cv value, which is an index of flowability, is also stabilized, and since it is used with a small stroke during actual use, it has been reported that durability can be ensured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the method of Patent Document 2 has the following problems. First, in this method, opening and closing aging is performed with the lift amount remaining at the unadjusted full stroke. When the lift amount is unadjusted, the lift amount varies within a range of, for example, 1.1 mm to 1.3 mm due to individual differences in the valves. When opening and closing aging is performed in this state, the impact force applied to the seat during the opening and closing operation varies between diaphragm valves, the effect of the opening and closing aging also varies, and as a result, variations occur in durability and flow characteristics for each product. Such variations are not preferable in recent years when the demand for reducing machine differences is increasing. Second, in the method of Patent Document 2, since opening and closing aging is performed with a large lift amount such as 1.2 mm before adjustment, the amount of strain ε of the diaphragm during opening and closing aging (when the outer diameter is D, the thickness is t, and the lift amount is ΔS, the amount of strain ε is considered to be proportional to tΔS / D) becomes large, and there is concern that the opening and closing aging may affect the durability of the diaphragm.

[0006] An object of the present invention is to provide a method for manufacturing a diaphragm valve that can solve the above problems, reduce the change over time of the flow rate and the variation between products, and reduce the influence on the durability of the product.

Means for Solving the Problems

[0007] The method for manufacturing a diaphragm valve of the present invention is a body having a valve chamber opened on the upper surface, and a fluid inflow passage and a fluid outflow passage respectively opened on the bottom surface of the valve chamber provided inside, an annular sheet disposed around the opening of the fluid inflow passage on the bottom surface of the valve chamber, a diaphragm disposed so as to seal the valve chamber, and closing and opening the fluid inflow passage by elastically deforming and contacting and separating from the sheet, a diaphragm operation part whose tip rises and falls while pressing the diaphragm, and contacts and separates the diaphragm from the sheet, and is a method for manufacturing a diaphragm valve provided with, a step of adjusting the rising amount of the tip of the diaphragm operation part when separating from the pressing against the sheet of the diaphragm to a predetermined amount, and then, a step of performing a running-in operation in which the diaphragm is contacted and separated from the sheet a predetermined number of times by the diaphragm operation part, characterized by including.

[0008] Preferably, a configuration can be adopted in which the step of performing the running-in operation is performed at any temperature within a temperature range of 80°C to 150°C.

[0009] Preferably, a configuration that is the upper limit temperature of the use temperature range of the diaphragm valve can be adopted.

[0010] Preferably, the diaphragm is a circular laminate with an outer diameter of 14.5 mm to 26.5 mm, which is composed of a stainless-steel thin plate and a nickel-cobalt alloy thin plate, and the predetermined number of times is at least 10,000 times, and such a configuration can be adopted.

[0011] Preferably, the predetermined amount of the elastic deformation stroke is 0.3 mm to 0.4 mm, and such a configuration can be adopted.

[0012] Preferably, after the step of performing the running-in operation, a step of adjusting the Cv value of the diaphragm valve is further included, and such a configuration can be adopted.

Advantages of the Invention

[0013] According to the present invention, after adjusting the amount of rise (hereinafter referred to as "lift amount") of the tip of the diaphragm operating part at the time of separation with respect to the pressing of the diaphragm against the sheet, the opening and closing operation is performed a predetermined number of times (hereinafter referred to as "opening and closing aging"). Therefore, during the opening and closing aging, the lift amount does not vary among individual valves, and the variations in durability and flow rate among individual valves due to the variations in the effects of the opening and closing aging can be reduced. In addition, since the opening and closing aging is performed with a small lift amount (for example, the lift amount at the time of product shipment is 0.3 mm), the adverse effect on the durability of the diaphragm can be minimized. Empirically, if the lift amount is 0.3 mm, the durability of the diaphragm is 40 million times of opening and closing in terms of actual strength. Therefore, it is considered that there is no problem even if the opening and closing aging is performed 10,000 times.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0015] (Diaphragm valve of the embodiment of the present invention) Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the same NC (normally closed) type direct diaphragm valve as in Patent Document 2 will be described as an example. FIG. 1 is a schematic cross-sectional view of this direct diaphragm valve. Further, FIG. 2 is an enlarged cross-sectional view when the diaphragm is in its natural shape in FIG. 1, FIG. 3 is an enlarged cross-sectional view showing the state where the diaphragm is in contact with the seat in FIG. 1, and FIG. 4 is an enlarged cross-sectional view showing the state where the diaphragm is separated from the seat in FIG. 1.

[0016] In FIG. 1, 1 is the body, 2 is the diaphragm, 3 is the retainer adapter, 4 is the bonnet, 5 is the screw portion, 6 is the spring, 7 is the diaphragm retainer, 8 is the stem, 9 is the actuator, 10 is the fluid inlet, 11 is the fluid outlet, 12 is the valve chamber, 13 is the seat, 14 is the drive shaft, 15 is the stroke adjustment mechanism, 16 is the solenoid valve, and 17 is the proximity switch.

[0017] The body 1 is formed in a substantially cross shape from stainless steel, with fluid inlets 10 and fluid outlets 11 on both sides, and a concave valve chamber 12 that is open at the top and communicates with the fluid inlets 10 and fluid outlets 11 formed on the upper part. Also, a sheet 13 made of synthetic resin (such as PFA, PA, PI, PCTFE, etc.) is fitted and fixed to the bottom surface of the valve chamber 12. In this embodiment, the sheet 13 is fixed in the valve insertion groove by so-called caulking.

[0018] The diaphragm 2 is disposed above the sheet 13, maintains the airtightness of the valve chamber 12, and its central part moves up and down to contact and separate from the sheet 13. In this embodiment, the diaphragm 2 is formed into a circular inverted dish shape by bulging the central parts of thin metal plates (thickness 0.15 mm) such as special stainless steel and thin nickel-cobalt alloy plates (thickness 0.15 mm) upward, and is formed into an inverted dish shape by closely laminating three sheets of this special stainless steel thin plate in an inverted dish shape and one sheet of nickel-cobalt alloy thin plate. Also, the peripheral part of this diaphragm 2 is placed on the protrusion on the inner peripheral surface of the valve chamber 12, and by screwing the lower end of the bonnet 4 inserted into the valve chamber 12 into the screw part 5 of the body 1, it is pressed against the protrusion side of the body 1 via the presser adapter 3 made of stainless steel and is held and fixed in an airtight state. The nickel-cobalt alloy thin film is disposed on the gas contact side.

[0019] In this embodiment, the diaphragm 2 has an outer diameter of 26 mm for a valve with a fluid passage inner diameter of 6.35 mmφ and a curvature radius of the bulging part of 60 mm. In addition to this, there are diaphragms with an outer diameter of 20 mm for a valve with a fluid passage inner diameter of 6.35 mmφ and a curvature radius of 62.6 mm, and diaphragms with an outer diameter of 15 mm for a small valve with a 6.35 mmφ and a curvature radius of 62.6 mm, etc.

[0020] The bonnet 4 is formed in a cylindrical shape, is inserted into the valve chamber 12 of the body 1, and is fixed to the body 1 side by being tightened into the screw part 5 provided on the inner peripheral surface of the valve chamber 12.

[0021] The stem 8 is inserted into the lower end of the bonnet 4 so as to be vertically movable, and a synthetic resin diaphragm presser 7 that abuts on the upper surface of the central portion of the diaphragm 2 is fitted to the lower end surface.

[0022] More specifically, the stem 8 is vertically movably inserted into the bonnet 4 so that the polyimide diaphragm presser 7 attached to the lower end surface abuts on the diaphragm 2, and is pressed downward via the diaphragm presser 7 by the elastic force of the spring 6, and the central portion of the diaphragm 2 is seated on the seat 13. Further, a drive shaft 14 of an actuator 9 for stem operation is fixed to the upper end portion of the stem 8.

[0023] In addition, a flange portion 8a is provided at the lower portion of the stem 8, and when the valve is fully closed (when the central portion of the diaphragm 2 is seated on the seat 13), the flange portion 8a abuts on the upper surface of the presser adapter 3, thereby restricting excessive descent of the stem 8.

[0024] The stroke adjustment mechanism 15 is composed of a lock nut 15a screwed onto a support cylinder portion 9a of the actuator 9 fixed by screwing onto the upper surface of the bonnet 4, and adjusts the magnitude of the lift amount ΔS by adjusting the screwed height position of the support cylinder portion 9a into the bonnet 4.

[0025] The solenoid valve 16 is directly fixed to the upper surface of the actuator 9 and controls the flow of the driving fluid (air) A supplied into the actuator 9. The reason for directly attaching the actuator 9 to the solenoid valve 16 is to reduce the space portion of the driving fluid passage as described later and enhance the responsiveness of the valve opening / closing operation (shorten the opening / closing operation time).

[0026] Further, the proximity switch 17 is for detecting the change state of the lift amount ΔS and the lift amount ΔS itself during the valve opening / closing operation, and is fixed to the upper surface side of the actuator 9, and detects the lift amount ΔS by measuring the gap ΔG with the piston 9c.

[0027] Next, the operation of the diaphragm valve of the present embodiment will be described. The valve shown in Fig. 1 is configured as an NC (Normally Closed) type. Normally, the diaphragm 2 is pressed downward via the stem 8 by the elastic force of the spring 6, and the nickel-cobalt alloy thin plate on its lower surface (gas contact surface) abuts against the seat 13. The pressing force of the stem 8 is adjusted by the spring 6, and the descending amount of the stem 8 is restricted by the retainer adapter 3.

[0028] When the driving fluid A is supplied to the actuator 9, the drive shaft 14 is lifted upward by an amount ΔS via the piston 9c. As a result, the diaphragm 2 is restored to a form in which its original central portion bulges upward by its elastic force, and the valve is opened. The lift amount ΔS is adjusted to a predetermined value by the lock nut 15a of the stroke adjustment mechanism 15.

[0029] (Manufacturing method of the embodiment of the present invention) Next, the manufacturing method of the present invention for such a diaphragm valve will be described. The manufacturing method of the present embodiment is a method including a step of adjusting the lift amount (hereinafter referred to as "lift amount") of the tip of the diaphragm operating portion at the time of separation when pressing against the seat of the diaphragm as a running-in operation (aging) method, then performing a predetermined number of opening and closing operations (hereinafter referred to as "opening and closing aging"), and further performing flow lift adjustment. Fig. 5 shows the flowchart of the present embodiment. The manufacturing method of the present embodiment is (a) Component manufacturing process, (b) Component cleaning and baking process, (c) Valve assembly process, (d) Aging (running-in operation), (e) Inspection process (He leak inspection, pressure inspection, cleanliness inspection, etc.), and includes. The feature of the manufacturing method of the present invention lies in the (d) aging (running-in operation) method. For the other (a), (b), (c), and (e) processes, they are the same as the conventional methods, so detailed descriptions of these processes are omitted. The (d) aging process of this embodiment includes (d1) lift amount adjustment, (d2) opening / closing aging, and (d3) flow rate lift adjustment (Cv value adjustment).

[0030] (d1) Lift amount adjustment This process is a process of adjusting the ascending amount (i.e., "lift amount") of the tip of the diaphragm operation part at the time of separation with respect to the pressing of the diaphragm to the seat. The purpose of this process is to ensure that the aging effect of the seat due to opening and closing is constant among each valve in the (d2) opening / closing aging described later, and also to prevent the load on the diaphragm due to opening / closing from becoming excessive and affecting the valve life. The lift amount set value is set to a predetermined value of 0.3 to 0.4 mm.

[0031] The reason for this is that in the opening / closing aging, the greater the lift amount, the greater the impact force when closing, so it is considered that the aging effect is also greater. However, in the Cv value stability evaluation described later, a sufficient stabilization effect has been obtained with the opening / closing aging of a lift amount of 0.3 mm. Also, as described later, regarding the strain amount ε of the diaphragm during opening / closing aging (when the outer diameter is D, the thickness is t, and the lift amount is ΔS, the strain amount ε is considered to be proportional to tΔS / D), if the lift amount ΔS is 0.3 to 0.4 mm, the strain amount ε will be smaller than that in the case of the opening / closing aging of Patent Document 2 for any of the diaphragm outer diameters of 26 mm, 20 mm, and 15 mm. Also, empirically, if the actual use lift amount is 0.3 mm, since the durability of the diaphragm has an actual value of 40 million opening / closing cycles, it is considered that the impact on durability due to opening / closing aging is small.

[0032] Specifically, for example, while monitoring the height direction position of the piston 9c by the proximity switch 17 of the diaphragm valve shown in FIG. 1, the operating air is turned on and off, the change in the height position is measured, and this is used as the lift amount. To make this lift amount, for example, 0.3 mm, the actuator 9 screwed to the bonnet 4 is rotated, and the vertical position of the actuator 9 is adjusted to adjust the upper limit position of the diaphragm retainer 7 connected via the actuator 9, the drive shaft 14, and the stem 8. After adjustment, the lock nut 15a screwed to the outer peripheral screw portion of the support cylinder portion 9a of the actuator 9 is tightened and fixed.

[0033] (d2) Opening and closing aging Opening and closing aging is a process of opening and closing the valve a number of times under high temperature conditions and pressing the seat against the diaphragm a number of times impactfully. The purpose of this process is to complete the change over time of the seat by this opening and closing aging so that such a change does not occur after delivery to the customer. Opening and closing aging is performed, for example, under the conditions shown in Table 1.

Table 1

[0034] Figure 6 is an explanatory diagram showing the opening and closing aging method. In the test apparatus shown in Figure 6, diaphragm valves configured as three air-operated valves can be opened and closed in parallel for aging. Each diaphragm valve is disposed in a thermostat set at a temperature of 120°C. The primary side is open to atmospheric pressure, and the secondary side is evacuated by a vacuum pump. For the solenoid valve 16 (see Figure 1) of each diaphragm valve (air-operated valve), nitrogen gas (0.5 MPa) is supplied from the operation unit as operating air, and a signal for turning the solenoid valve ON / OFF is also supplied from the operation unit. Thereby, opening and closing are performed a predetermined number of times at a predetermined opening and closing speed.

[0035] (d3) Flow rate lift adjustment (Cv value adjustment) In this step, after aging, the lift amount is adjusted again so that the Cv value, which represents the ease of flow of the controlled fluid when the valve is fully open, reaches a predetermined value. Although not an essential step in the present invention, it is preferably implemented because it is a step of confirming whether a predetermined flow rate can be obtained at full open under high temperature conditions (for example, 120°C) where the sheet expands and the flow path is likely to be narrowed. For this purpose, it is preferable to set the temperature in this step as high as possible within the usable temperature range of the product. The method for adjusting the lift amount in this step is the same as in the case of (d1), that is, the actuator 9 screwed to the bonnet 4 is rotated to adjust the vertical position of the actuator 9. When the fluid is a gas, the Cv value is obtained by the following formula (1). [Number] In Equation (1), Qg [m 3 / h (standard condition)] is the gas flow rate under standard conditions (15 °C, 760 mmHg abs), t [°C] is the gas temperature, Gg is the specific gravity of the gas (when air = 1), P1 [MPa abs] is the primary side absolute pressure, and P2 [MPa abs] is the secondary side absolute pressure.

[0036] Figure 7 is an explanatory diagram showing the Cv value measurement method. Using the Cv value measurement test apparatus shown in Figure 7, the mass flow rate Qg of nitrogen gas N2 supplied from an N2 (nitrogen gas) supply source is measured with a mass flow controller MFC, and the nitrogen gas N2 is heated to a predetermined temperature (120 °C), passed through the diaphragm valve of the test specimen (open state with a predetermined lift amount), and released to the atmosphere through a dry pump DP. At this time, the pressures on the primary side and secondary side of the diaphragm valve are measured with pressure gauges P and P, respectively. Using the measurement results, the Cv value is calculated by the above Equation (1).

[0037] (Effect of the Embodiment of the Present Invention) Figure 8 is a graph showing the change in Cv value due to opening / closing aging. In this evaluation, three test valves were used, and opening / closing aging was performed with a lift amount of 0.3 mm. For each valve, every 10,000 test opening / closing times, it was taken out from the opening / closing aging apparatus shown in Figure 6, and the Cv value was measured with the Cv measurement test apparatus shown in Figure 7. The test conditions are shown in Table 2. [Table 2] As a result, as shown in the graph of Figure 8, for each valve, the Cv value increased by about 15% from the initial set Cv value of 0.117, and it can be seen that the change in the Cv value stabilizes after 10,000 opening / closing aging times.

[0038] Next, Figure 9 is a graph showing the change in Cv value due to open storage at 120 °C. Three valves that underwent opening and closing aging 10,000 times with a lift amount of 0.3 mm and three valves that did not undergo opening and closing aging were used to comparatively evaluate the change in Cv value due to open storage at 120°C. The test conditions are shown in Table 3.

Table 3

[0039] Thus, it is considered that the reason why the change in Cv value due to subsequent open storage at 120°C becomes small when opening and closing aging is performed is as follows. As shown in Figure 10, before opening and closing aging, there are gaps between the molecules of resin materials such as PTFE and PFA that make up the sheet, so the sheet has room for deformation corresponding to the gaps. Next, when opening and closing aging is performed at 120°C, the sheet is repeatedly pressed and crushed, eliminating the gaps between the molecules and leaving no room for deformation, thereby stabilizing the shape. Furthermore, when open storage is performed at 120°C, the gaps between the crushed molecules slightly expand, increasing the room for deformation. However, since the room for deformation is reduced compared to before opening and closing aging, it is considered that the amount of deformation decreases.

[0040] (Summary of effects) (1) Cv value stabilization effect by opening and closing aging Due to the opening and closing aging of this embodiment, even with a small lift amount of 0.3 mm, a sufficient reduction effect on the change in Cv value over time and a reduction effect on the change in Cv value during open storage at 120°C were confirmed. In opening and closing aging, it is considered that the greater the lift amount, the greater the impact force when closing, so the aging effect is also greater. However, in this embodiment, a sufficient effect was obtained even with a lift amount of 0.3 mm, which is smaller than the lift amount of about 1.1 mm for opening and closing aging in the case of Patent Document 2.

[0041] (2) Influence of opening and closing aging on diaphragm durability Although experiments on this point have not been conducted this time, based on experience, if the lift amount during use is 0.3 mm, the diaphragm has a durability of 40 million opening and closing cycles in terms of its actual performance. Therefore, it is considered that opening and closing aging of about 10,000 cycles will not pose a problem to the diaphragm's durability. Let's consider the case where the lift amount ΔS during opening and closing aging is set to 0.4 mm. When the outer diameter of the diaphragm is D, the thickness is t, and the lift amount is ΔS, the amount of strain ε caused by the opening and closing of the diaphragm is considered to be proportional to tΔS / D. When the diaphragm outer diameter D = 26 mm, tΔS / D = 0.015t; when the diaphragm outer diameter D = 20 mm, tΔS / D = 0.02t; when the diaphragm outer diameter D = 15 mm, tΔS / D = 0.027t. In all cases, the strain amount ε is smaller than that in the case of Patent Document 2 (outer diameter 26 mm, lift amount 1.1 mm, tΔS / D = 0.042t). Even in this case, it is considered that the influence of opening and closing aging on the diaphragm life is small.

[0042] Note that the present invention is not limited to the above-described embodiments. Those skilled in the art can make various additions, changes, etc. within the scope of the present invention. For example, in this embodiment, the manufacturing method of the present invention is applied to a diaphragm valve configured as an air-operated valve using an air cylinder as an actuator. However, the manufacturing method of the present invention is not limited to this and can also be applied to diaphragm valves using a solenoid or a piezo element as an actuator.

Explanation of Reference Numerals

[0043] 1: Body 2: Diaphragm 3: Pressing adapter 4: Bonnet 5: Threaded part 6: Spring 7: Diaphragm presser 8: Stem 8a: Flange part 9: Actuator 9a: Support cylinder part (piston) 10: Fluid inlet 11: Fluid outlet 12: Valve chamber 13: Sheet 14: Drive shaft 15: Stroke adjustment mechanism 15a: Lock nut 16: Solenoid valve 17: Proximity switch ΔS: Lift amount D: Outer diameter of diaphragm t: Thickness ε: Strain amount

Claims

1. A body having a valve chamber opened at the top, and a fluid inlet passage and a fluid outlet passage respectively opened at the bottom surface of the valve chamber are provided inside; An annular sheet disposed around the opening of the fluid inlet passage on the bottom surface of the valve chamber; A diaphragm disposed to seal the valve chamber, which elastically deforms to contact and separate from the sheet to close and open the fluid inlet passage; A diaphragm operating portion whose tip rises and falls while pressing the diaphragm to contact and separate the diaphragm from the sheet; A method for manufacturing a diaphragm valve, comprising: Adjusting the rising amount of the tip of the diaphragm operating portion when separating from the pressing against the sheet of the diaphragm to a predetermined amount; Thereafter, performing a running-in operation of contacting and separating the diaphragm from the sheet a predetermined number of times by the diaphragm operating portion, The diaphragm is a circular laminate with an outer diameter of 14.5 mm to 26.5 mm made of a laminate of a stainless steel thin plate and a nickel-cobalt alloy thin plate, and the predetermined number of times is at least 10,000 times; The predetermined amount is 0.3 mm to 0.4 mm; A method for manufacturing a diaphragm valve.

2. The method for manufacturing a diaphragm valve according to claim 1, wherein the step of performing the running-in operation is performed at any temperature within a temperature range of 80°C to 150°C.

3. The method for manufacturing a diaphragm valve according to claim 2, wherein the temperature is the upper limit temperature of the use temperature range of the diaphragm valve.

4. The method for manufacturing a diaphragm valve according to any one of claims 1 to 3, further comprising a step of adjusting the Cv value of the diaphragm valve after the step of performing the running-in operation.

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