KR101288478B1 - Method of manufacture of ozone resistant polyurethane lining butterfly valve - Google Patents

Abstract

The present invention relates to a method of lining a butterfly valve used in an ozone treatment line of an advanced water treatment plant with an ozone-resistant polyurethane having excellent ozone resistance to the inner surface of the valve body, which is a fluid contacting area, in order to protect against strong corrosion of ozone. .
It is an object of the present invention to provide a method of lining a highly viscous ozone-resistant polyurethane on the complex inner surface of a butterfly valve. Another object of the present invention is to provide a method for preventing the occurrence of bubbles or interfaces that can reduce the ozone resistance of the polyurethane itself in the process of injecting and molding the polyurethane for ozone resistance in a state in which the butterfly valve body and the mold are combined. It is.
The method for lining the ozone-resistant polyurethane in the butterfly valve according to the present invention comprises the steps of: providing an upper mold and a lower mold corresponding to the inner surface of the valve body; Forming one raw material inlet, two side outlets, and one lower outlet, apply release agent to the inner surface of the upper and lower molds, apply adhesive to the inner surface of the valve body, and then Coupling to the valve body, putting the assembled mold and the valve body in the furnace and heating to a temperature of 90 ~ 100 ℃, 20 parts by weight of toluene diisocyanate (C ₉ H ₆ O ₂ N ₂ ) and polytetramethylene glycol (C ₄ H ₈ O) 100 parts by weight of a prepolymer to react 80 parts by weight and 0.8 to 2.8 parts by weight of benzophenone (C ₆ H ₅ COC ₆ H ₅ ), a UV stabilizer, at a temperature of 90 to 100 ° C. for 25 to 35 minutes Under stirring Step, the bridge half in the sulfur-containing amine curing agent _{(C 9 H 4 N 2 S} 2) 8 ~ 14 parts by weight of mixing at a temperature of 90 ~ 100 ℃, the assembled mold and the valve body material inlet is flows to the top 15 to 45 ° tilting step, injecting the mixture into the mold inlet of the mold, blocking each outlet when the raw material flows from the left and right outlets, bubbles trapped in the polyurethane discharged through the lower outlet Maintaining flow until it is not visible while observing with the naked eye, remove the injector, put the assembled mold and valve body into the furnace, and the first aging step to maintain at a temperature of 90 ~ 100 ℃, remove the mold from the valve body Putting the polyurethane molded valve body for ozone into the furnace and includes a second aging step to maintain at a temperature of 60 ~ 70 ℃.
According to the present invention, a high viscosity ozone-resistant polyurethane having good ozone resistance even at a high concentration of about 8 ppm of ozone water can be lined on the inner surface of a butterfly valve of a complicated structure. The inherent properties of the urethane itself have the effect that it can be maintained even after the lining is completed.

Description

Method of manufacture of ozone resistant polyurethane lining butterfly valve

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for lining a polyurethane for ozone resistance on an inner surface of a valve body in a butterfly valve mounted on a water supply pipe, a sewer pipe, or the like to maintain airtightness by a disc. More specifically, the present invention is a specific method of lining the butterfly valve used in the ozone treatment line of an advanced water treatment plant with a polyurethane having excellent ozone resistance to the inner surface of the valve body, which is a fluid contacting area, in order to protect against strong corrosion of ozone. It is about. Polyurethane for ozone is used to prevent corrosion of the equipment installed in the ozone water flow line of the advanced water treatment plant, and a special lining process is required to apply it to the butterfly valve. By lining the body inner surface of the butterfly valve with a polyurethane for ozone resistance over a certain thickness, the valve has a strong ozone resistance.

In order to have the corrosion resistance of a butterfly valve mounted on a water supply pipe or the like, a control valve having a polyurethane coating layer formed on the outer surface of the disc and the inner surface of the valve body, respectively, is disclosed in Utility Model Registration Application No. 1998-20263. As a result, the fluid does not come into direct contact with the disk and the valve body of the metal, thereby preventing the occurrence of rust due to corrosion, thereby providing sanitary tap water and improving the durability of the valve. On the other hand, in the control valve in which the polyurethane coating layer is formed, no specific method of lining the polyurethane on the inner surface of the valve or the outer surface of the disk is not presented.

Advanced water treatment plants use ozone (O ₃ ) as a means to disinfect water. Ozone is very strong in oxidizing power, and the surface of the pipe and the inside of the ozone contact tank should be treated with a material that is resistant to ozone, especially corrosion resistant to ozone. Ozone is composed of three oxygen atoms and has the strongest oxidizing power after fluorine. As a result, sterilization, deodorization, desalination and reaction with organic or inorganic substances are very strong. The strong oxidizing power of ozone means strong sterilizing power, which is used in many fields as well as in advanced water treatment plants since it does not cause residual substances, that is, secondary pollution.

Ozone dissolved water is called ozone water, and the half life of ozone in ozone water is very short, about 25 minutes. Therefore, ozone water is widely used for the sterilization of water in the advanced treatment plant or for preventing the corruption of food in the food treatment plant. In most water treatment plants, advanced treatment plants often include ozone disinfection.

The powerful oxidizing power of ozone not only acts as a bactericidal but also rapidly oxidizes or corrodes other substances. Since the oxidizing power of ozone corrodes the equipment using ozone, ozone-resistant materials must be used for the equipment using ozone. Ozone-resistant materials known to date include metals such as stainless steel, brass and pig iron and plastics such as polyvinyl chloride (PVC) and Teflon, and polyethylene (PE) and ethylene propylene. There is synthetic rubber.

As demand for using ozone water increases, facilities are diversified, and the development of materials constituting each facility is also active. Rubber is a representative example of the material used as a partial component in ozone water plants, which has the disadvantage of being extremely vulnerable to ozone water. Since rubber has elasticity, it is mainly used as a sealing material. As a material for replacing this, polyurethane having elasticity is suitable. Polyurethanes are generally known to be very resistant to ozone as a result of tests on ozone in the air.

The present invention provides a method for producing a polyurethane lining butterfly valve for ozone having a strong resistance (corrosion resistance) even in a high concentration of ozone water. According to the present invention, a butterfly valve lined with an ozone-resistant polyurethane can be used without corrosion or cracking even at an ozone water concentration of about 8 ppm, which is much higher than the ozone concentration of 1 to 2 ppm of ozone water normally used in water treatment. have.

An object of the present invention is to provide a method for producing a polyurethane lining butterfly valve for ozone, which has good ozone resistance even at a high concentration of about 8 ppm of ozone water. The method of lining the ozone-resistant polyurethane on the body of the valve is an important process for maintaining the ozone resistance as it is after the lining is completed.

Since ozone-based polyurethanes have a higher viscosity than ordinary polyurethanes, lining in complex structures such as the inner surface of the butterfly valve body requires considerable technical skills and know-how. It is therefore an object of the present invention to provide a method of lining a highly viscous ozone-resistant polyurethane on the complex inner surface of a butterfly valve.

Another object of the present invention is to provide a method for preventing the occurrence of bubbles or interfaces that can reduce the ozone resistance of the polyurethane itself in the process of injecting and molding the polyurethane for ozone resistance in a state in which the butterfly valve body and the mold are combined. It is.

The above objects of the present invention can be achieved by the present invention described in detail below.

In the manufacturing method of the ozone-resistant polyurethane lining butterfly valve installed in the pipeline for conveying the fluid according to an embodiment of the present invention is composed of a cylindrical body and a disk disk to control the flow of the fluid by the rotation of the disk A top mold 20 and a bottom mold 21 for securing a space in which the ozone-resistant polyurethane 30 is to be lined corresponding to the inner surface of the cylindrical valve body 10; Forming one raw material inlet (22), two side outlets (23), and one lower outlet (24) in the form of four radial holes at the upper edge of the upper mold (20); Apply a release agent to the inner surface of the upper mold 20 and the lower mold 21, apply an adhesive to the inner surface of the valve body 10, and then the lower mold 21 and the upper mold 20 to the valve body 10 After seating on the), and assembling the mold using a bolt and nut; A mold preheating step of placing the assembled molds 20 and 21 and the valve body 10 in a furnace and heating them to a temperature of 90 to 100 ° C .; 20 parts by weight of toluene diisocyanate (C ₉ H ₆ O ₂ N ₂ ) and 80 parts by weight of polytetramethylene glycol (C ₄ H ₈ O) are reacted with 100 parts by weight of prepolymer and benzophenone (C ₆₎ H ₅ COC ₆ H ₅ ) Stirring 0.8 ~ 2.8 parts by weight for 25 to 35 minutes at a temperature of 90 ~ 100 ℃; Mixing 8-14 parts by weight of a sulfur-containing amine curing agent (C ₉ H ₄ N ₂ S ₂ ) in the stirring solution at a temperature of 90 ~ 100 ℃; Inclining the assembled mold (20, 21) and the valve body (10) by 15 to 45 degrees so that the raw material inlet (22) goes to the top; Injecting the mixed solution into the raw material injection port 22 of the upper mold 20; Blocking each side outlet 23 when raw material flows from the side outlet 23 of the upper mold 20; When the ozone-resistant polyurethane 30 raw material flows out from the lower outlet 24 of the upper mold 20, when air bubbles trapped in the polyurethane exiting through the lower outlet are not visible with the naked eye, Maintaining the flow out; Putting the assembled molds (20, 21) and the valve body (10) in a furnace and maintaining a primary aging step for 2 to 4 hours at a temperature of 90 to 100 ℃; After removing the molds (20, 21) from the valve body 10, the second body aging to put the valve body 10 lined with the ozone-resistant polyurethane 30 in the furnace for 5 to 6 hours at 60 ~ 70 ℃ temperature Step 62; And a control unit.

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Hereinafter, the details of the present invention will be described in detail.

According to the present invention, a high viscosity ozone-resistant polyurethane having good ozone resistance even at a high concentration of about 8 ppm of ozone water can be lined on the inner surface of a butterfly valve of a complicated structure. The inherent properties of the urethane itself have the effect that it can be maintained even after the lining is completed.

In addition, the butterfly valve completed by the present invention is an ozone butterfly valve has an effect that can be used without corrosion even at a high ozone water concentration when used in connection with the ozone water pipe of the advanced water treatment plant.

Figure 1. Butterfly valve body before lining polyurethane for ozone.
Figure 2. Butterfly valve body after lining polyurethane for ozone.
3. Upper and lower molds for carrying out the present invention.
4. (a) is a perspective view, (b) is a perspective view of the upper mold and the lower mold coupled to the valve body.
5 is a view showing a state of injecting the ozone-resistant polyurethane into a mold.
Figure 6 is a view showing the entire butterfly valve lining the polyurethane for ozone on the inner surface of the body by the present invention.
7. Flowchart of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to explain in detail enough to enable those skilled in the art to easily carry out the invention, and thus It is not intended that the technical spirit and scope of the invention be limited.

1 is a view showing the valve body of the butterfly valve before lining the polyurethane for ozone, Figure 2 is a view showing the butterfly valve body after lining the polyurethane for ozone. As shown, the ozone-resistant polyurethane 30 is lining more than a certain thickness on the inner surface of the valve body 10 through the lining according to the present invention. The inner surface of the valve body 10 is a portion where the fluid directly touches when using the butterfly valve, and is greatly affected by corrosion by the fluid.

The ozone-resistant polyurethane 30 lining the inner surface of the butterfly valve has a thickness of 3 to 5 mm depending on the part, and the upper and lower molds to ensure accurate water tightness with the disk 40 blocking the fluid. Lining using. Lining of the ozone-resistant polyurethane 30 is made by injecting the raw material in the liquid state into the mold (20, 21) to harden, as shown in the polyurethane for ozone lining along the inner surface of the butterfly valve body The shape of 30 is quite complicated. In addition, the ozone-resistant polyurethane 30 has a very high viscosity of the raw material to be injected, so that the flow in the molds 20 and 21 is not good. Therefore, lining the polyurethane 30 for ozone so as to have no bubble or interface is quite difficult.

3 is a view showing the upper mold 20 and the lower mold 21 for the practice of the present invention. As shown, the lower mold 21 is higher in height than the upper mold 20 to facilitate the lining of the polyurethane 30 for ozone resistance of the shaft portion. Since the shaft portion must maintain the watertight while transmitting the force for rotating the disk 40, the ozone-resistant polyurethane 30 lining of the shaft portion should be particularly not to create an interface. Therefore, the lower mold 21 included in the present invention should maintain the height so that it can include a shaft portion.

As shown in FIG. 3, four vent holes are radially formed in the flange portion of the upper edge of the upper mold 20. The vent is divided into one raw material inlet 22, two side outlets 23 and one lower outlet 24 according to the purpose. The raw material inlet 22 is used to inject the ozone-resistant polyurethane 30 into the molds 20 and 21, and the side outlet 23 and the lower outlet 24 are inside the molds 20 and 21. It acts as an air outlet for the air to escape. The operation of the side outlet 23 and the bottom outlet 24 will be discussed in detail below.

As shown, a plurality of through-holes that can be fastened between the molds are formed at the lower end of the upper mold 20 and the upper end of the lower mold 21. The plurality of holes serve to fasten the upper mold 20 and the lower mold 21 using bolts and nuts, and the upper mold 20 and the plurality of through holes using bolts and nuts. Means for binding the lower mold 21 corresponds to conventional techniques, and thus description thereof will be omitted.

Figure 4 (a) is a view showing a perspective view of the upper mold and the lower mold coupled to the valve body, (b) is a view showing a perspective view. First, the lower mold 21 is placed and the valve body 10 is placed thereon, and the upper mold 20 is inserted into the valve body 10. Then, the lower mold 21 and the upper mold 20 are bound using bolts and nuts. When the upper mold 20 and the lower mold 21 are fastened to the valve body 10, a space is formed between the molds 20 and 21 and the valve body 10. The space is a space in which the ozone-resistant polyurethane 30 is injected, and maintains a thickness of about 3 ~ 5mm depending on the position.

As shown in Figure 4 (b), the ozone-resistant polyurethane 30 is filled in the space formed by the inner surface of the valve body 10 and the outer surface of the mold (20, 21), in a liquid state The injected ozone-resistant polyurethane 30 is cured to a solid state after 3 to 5 minutes of pot life. As shown, the shape of the ozone-resistant polyurethane 30 lining along the inner surface of the valve body 10 is quite complicated compared to the viscosity of the ozone-resistant polyurethane. This will be discussed in detail below.

When the upper mold 20 and the lower mold 21 are removed from the valve body 10, the ozone-resistant polyurethane is lined on the inner surface of the valve body 10, and the ozone-resistant polyurethane 30 and the valve body ( 10) The adhesion between them is an important factor in determining the durability of the valve. Since the ozone-resistant polyurethane 30 should be strongly adhered to the valve body 10, an adhesive is applied to the inner surface of the valve body 10 before the valve body 10 and the molds 20 and 21 are coupled to each other. A release agent is applied to the outer surface of (20, 21). The release agent plays a role of being able to be separated from the polyurethane 30 for ozone resistance when the molds 20 and 21 are removed. Since the adhesive applied to the valve body 10 and the release agent applied to the molds 20 and 21 correspond to conventional techniques, detailed description thereof is omitted in the present invention.

The assembled valve body 10 and the molds 20 and 21 are put in a furnace and preheated at a temperature of 90 to 100 ° C. The preheating time depends on the size of the valve. The larger the valve size, the higher the preheating time. The reason for preheating in the assembled state is to allow the polyurethane material for ozone in a liquid state to be smoothly injected into the molds 20 and 21. In addition, it is because the compounding temperature of the raw material for ozone-resistant polyurethane 30 demonstrated below is 90-100 degreeC. That is, to prevent the preheated polyurethane ozone 30 material from being cooled by the molds 20 and 21 or the valve body 10 during the injection process.

Polyurethanes for ozone resistance consist of three main components: mains, additives and hardeners. The main ingredient is a prepolymer obtained by reacting 20 parts by weight of toluene diisocyanate (C ₉ H ₆ O ₂ N ₂ ) with 80 parts by weight of polytetramethylene glycol (C ₄ H ₈ O). Use as an additive is benzophenone (C ₆ H ₅ COC ₆ H ₅ ). Further, the curing agent is a sulfur-containing amine curing agent _{(C 9 H 4 N 2 S} 2).

The blending ratio and blending conditions of the main composition, the additives, and the curing agent constituting the ozone-resistant polyurethane 30 are as follows. First, 100 parts by weight of the prepolymer and 0.8 to 2.8 parts by weight of the UV stabilizer are stirred at 90 to 100 ° C. for 25 to 35 minutes. Then, 8 to 14 parts by weight of the sulfur-containing amine curing agent is mixed in the stirring solution at a temperature of 90 ~ 100 ℃. Since the process is performed in a conventional three-component polyurethane injector, detailed description of the injector is omitted. However, the operating temperature of the three-component polyurethane injector, and the mixing ratio of the additives and the curing agent are important factors.

5 is a view illustrating a state in which the ozone-resistant polyurethane is injected into a mold. In order to inject the raw material of the ozone-resistant polyurethane 30 into the assembled mold through the injector, the inlet and outlet positions of the mold and the seating state of the mold are very important factors. First, the assembled molds 20 and 21 are placed at an angle of 15 to 45 ° with a horizontal surface. At this time, the raw material inlet 22 should be located at the highest position, and the lower outlet 24 should be located at the lowest position.

The reason why the molds 20 and 21 should make an angle of 15 to 45 degrees with the horizontal surface is due to the viscosity of the raw material of the polyurethane 30 for ozone resistance. In general, an angle of about 5 to 10 degrees is sufficient as long as it has the same viscosity as water. However, since the raw material for ozone-resistant polyurethane 30 is high in viscosity, some of the polyurethane 30 is injected in a flowing form rather than being filled from a low place. That is, when the raw material for ozone-resistant polyurethane 30 is injected, it initially rises from a low place as water, but when the raw material is filled to some extent, the remaining space is pushed in as if lava flows thereafter.

The seating angle of the mold is determined by the size of the valve or the temperature between 15 and 45 °. For example, when the valve size is large and the temperature is low, a high angle must be maintained. When the valve size is small and the temperature is high, the angle must be kept low. This is because the pot life of the ozone-resistant polyurethane 30 is affected by the temperature much, the lower the temperature, the shorter pot life of the ozone-resistant polyurethane 30 becomes shorter. In addition, if the diameter of the valve is large, the space for the ozone-resistant polyurethane 30 raw material to be pushed in the second half of the raw material injection is because it requires much help of gravity.

As shown in FIG. 5, the ozone-resistant polyurethane 30 raw material is injected through the raw material inlet 22, and when the raw material is filled to the inside of the mold 20 and 21 to some extent, the raw material through the side outlet 23. Flows out. At this time, by blocking the side outlet 23 to induce the raw material to flow toward the lower outlet (24). If the water is low in viscosity, it will be discharged first through the lower outlet 24, but the ozone-resistant polyurethane 30 is first discharged from the side outlet 23 due to the high viscosity, and finally the lower outlet 24 To be discharged.

The side outlet 23 and the lower outlet 24 are the main purpose of the discharge of the air remaining inside the mold (20, 21). The ozone-resistant polyurethane 30 is injected into the molds 20 and 21 to push out the air, and the lower outlet 24 and the side outlet 23 are the passages through which air flows out. In the process of injecting the ozone-resistant polyurethane 30, air is not sequentially escaped, but is trapped in the ozone-resistant polyurethane 30 in the middle, and remains in the form of bubbles, in order to discharge the lower outlet 24 Is not blocked as soon as the ozone-resistant polyurethane 30 is discharged, but waits until the predetermined amount of the ozone-resistant polyurethane 30 is discharged to prevent it.

After the injection of the raw material for the ozone-resistant polyurethane 30 is finished, the molds 20 and 21 and the valve body 10 are put into a furnace and subjected to the first aging step of maintaining the mixture at a temperature of 90 to 100 ° C. for 2 to 4 hours. In this process, the ozone-resistant polyurethane 30 is made of a polymer bond and the intermolecular bonding force increases. After the first aging step is completed, the upper mold 20 and the lower mold 21 are removed from the valve body 10, and then put back into the furnace to perform secondary aging for 5 to 6 hours at 60 to 70 ° C. Through the second aging step, the outer appearance of the ozone-resistant polyurethane 30 is more firmly formed.

After the above-described process, the valve body 10 of the butterfly valve is lining with the polyurethane 30 for ozone, and when combined with the disk 40, which is the main element of the butterfly valve, the butter for ozone is The fly valve is complete. The disk 40 uses a material that does not corrode even in ozone water, and typically uses stainless steel SSC16, which corresponds to conventional technology, and thus is not included in the gist of the present patent. Figure 6 is a view showing the entire butterfly valve lining the polyurethane for ozone on the inner surface of the body according to the present invention.

7 is a diagram illustrating a flowchart of the present invention. As shown, the present invention comprises the step of having a top mold 20 and the bottom mold 21 to secure a space to be lined with the polyurethane for ozone 30 corresponding to the inner surface of the valve body 10 51, forming one raw material inlet 22, two side outlets 23, and one lower outlet 24 at the upper end of the upper mold 20 ( 52).

The release agent is applied to the inner surface of the upper mold 20 and the lower mold 21, the adhesive is applied to the inner surface of the valve body 10, and then the lower mold 21 and the upper mold 20 are applied to the valve body 10. After seating, the mold assembly step 53 for joining using a bolt and a nut, and the mold preheating step 54 for putting the assembled molds 20 and 21 and the valve body 10 into a furnace and heating to a temperature of 90 to 100 ° C. ).

20 parts by weight of toluene diisocyanate (C ₉ H ₆ O ₂ N ₂ ) and 80 parts by weight of polytetramethylene glycol (C ₄ H ₈ O) are reacted with 100 parts by weight of prepolymer and benzophenone (C ₆₎ H ₅ COC ₆ H ₅ ) step of stirring 55 ~ 2.8 parts by weight at a temperature of 90 ~ 100 ℃ 25 ~ 35 minutes (55), sulfur-containing amine curing agent (C ₉ H ₄ N ₂ S ₂ ) 8 Mixing 56 parts by weight at a temperature of 90-100 ° C. (56).

Assembling the assembled mold (20, 21) and the valve body 10 15 to 45 ° so that the raw material inlet 22 to the top 57, the mixed liquid to the raw material inlet 22 of the upper mold 20 Injecting step 58, blocking each side outlet 23 when the raw material flows from the side outlet 23, 59, the raw material for ozone-resistant polyurethane 30 flows out from the lower outlet 24 Maintaining 60 to flow out at a time;

Remove the injector and put the assembled mold (20, 21) and the valve body (10) in the furnace for the first aging step 61, which is maintained for 2 to 4 hours at a temperature of 90 ~ 100 ℃, the mold in the valve body (10) 20, 21) after removing the ozone-resistant polyurethane 30 is lined in the furnace body 10 is composed of a second aging step 62 for 5 to 6 hours at 60 ~ 70 ℃ temperature.

10 ... valve body 20 ... upper mold
21 Lower mold 22 Raw material inlet
23 ... Side outlet 24 ... Bottom outlet
30.Ozone-resistant polyurethane 40 ... Disc

Claims (3)

In the manufacturing method of the ozone-resistant polyurethane lining butterfly valve is installed in the pipeline for transporting the fluid and composed of a cylindrical body and a disk disk to control the flow of the fluid by the rotation of the disk,
A step 51 having an upper mold 20 and a lower mold 21 for securing a space in which the ozone-resistant polyurethane 30 is lined corresponding to the inner surface of the cylindrical valve body 10;
Forming one raw material inlet 22, two side outlets 23, and one lower outlet 24 at the top edge of the upper mold 20 in the form of four radial vents; );
Apply a release agent to the inner surface of the upper mold 20 and the lower mold 21, apply an adhesive to the inner surface of the valve body 10, and then the lower mold 21 and the upper mold 20 to the valve body 10 After seating on the), a mold assembly step 53 for coupling using a bolt and a nut;
A mold preheating step 54 for putting the assembled molds 20 and 21 and the valve body 10 into a furnace and heating them to a temperature of 90 to 100 ° C .;
20 parts by weight of toluene diisocyanate (C ₉ H ₆ O ₂ N ₂ ) and 80 parts by weight of polytetramethylene glycol (C ₄ H ₈ O) are reacted with 100 parts by weight of prepolymer and benzophenone (C ₆₎ H ₅ COC ₆ H ₅ ) Stirring 0.8 to 2.8 parts by weight for 25 to 35 minutes at a temperature of 90 ~ 100 ℃ (55);
Mixing 56 to 14 parts by weight of a sulfur-containing amine curing agent (C ₉ H ₄ N ₂ S ₂ ) at a temperature of 90 to 100 ° C. to the stirring solution (56);
Inclining the assembled molds 20 and 21 and the valve body 10 by 15 to 45 degrees so that the raw material inlet 22 goes to the top 57;
Injecting (58) the mixture into the raw material inlet (22) of the upper mold (20);
Blocking (59) each side outlet (23) when raw material flows from the side outlet (23) of the upper mold (20);
When the ozone-resistant polyurethane 30 raw material flows out from the lower outlet 24 of the upper mold 20, when air bubbles trapped in the polyurethane exiting through the lower outlet are not visible with the naked eye, Maintaining 60 to flow out;
Putting the assembled mold (20, 21) and the valve body (10) in the furnace for the first aging step 61 for 2 to 4 hours at a temperature of 90 ~ 100 ℃;
After removing the molds (20, 21) from the valve body 10, the second body aging to put the valve body 10 lined with the ozone-resistant polyurethane 30 in the furnace for 5 to 6 hours at 60 ~ 70 ℃ temperature Step 62; Method for producing a ozone-resistant polyurethane lining butterfly valve comprising a. delete delete

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