JPH0258984B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is directed to seawater pipelines (water production plants),
This invention relates to a resin lining construction method for butterfly valves installed in water pipes, sewage pipes, chemical plants, etc.

Structure of conventional example and its problems As shown in Fig. 1, a conventional butterfly valve has a cylindrical casing 1 made of iron and a rubber lining 2 made of nitrile butyl rubber, chlorprene rubber, natural rubber, etc. laminated on the inner surface of the casing 1. The intermediate portion of the inner surface is made into a stepped portion, which serves as the valve contact portion 3. A metal valve shaft 4 passes through the casing 1.
The valve shaft 4 is rotatably supported by the casing 1 by a bearing device 5 including a seal structure. A valve body 7 having a valve surface 6 that can freely come into contact with the valve abutting portion 3 is attached to the valve stem 4, and the valve body 7 is made of iron, aluminum bronze alloy (AlBC-3),
Composed of Cu-Ni90/10, etc.

According to this conventional configuration, since the metal valve body 7 opens and closes relative to the rubber lining 2, the casing 1 including the support structure for the valve stem 4 and the valve body 7 have to be processed with high precision, and the rubber lining 2 with high construction precision. When these precisions are low, problems arise with sealing performance (water leakage).

A conventional configuration shown in FIG. 2 is also provided as one in which accuracy can be adjusted. That is, the annular rubber seal 9 is held between the outer end of the valve body 7 and the annular ring 8, and the annular ring 8 is moved closer to the valve body 7 by tightening the plurality of bolts 10, thereby removing the rubber seal 9. The sheet was stretched and deformed in the opposite direction, the sheet surface was corrected, and the sheet was sealed.

According to this conventional configuration, even if the accuracy is somewhat low, it can be adjusted, but on the other hand, since the rubber seal 9 is excessively deformed, there is a problem that it becomes tattered due to fatigue deterioration.

Yet another conventional configuration is provided as shown in FIG. That is, an annular groove 10 is formed on the inner surface of the casing 1, a rubber sealing material 11 is press-fitted into the annular groove 10 and fixed with an adhesive 12, and
Epoxy resin 13 is injected into the annular groove 10 on the back side of the rubber sealing material 11 and hardened.

With this conventional configuration, the rubber lining 2 does not require much construction precision, but the valve body 7 rotates forward and backward from the side relative to the rubber seal material 11, and the desired seal is achieved by elastic deformation of the rubber seal material 11. As a result, a peeling phenomenon occurs in the rubber sealing material 11 due to plucking, which causes cracking and deterioration. In order to reduce this cracking and deterioration, it is necessary to keep the surface pressure low, but lowering it will cause problems with sealing performance.

In order to solve these problems, it is conceivable to make the entire casing 1 made of resin so that no lining is required, but this increases the material cost.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a resin lining construction method for a butterfly valve, which is a resin lining method that is inexpensive in material cost, and which allows the resin lining to be made with high accuracy without any processing.

Structure of the Invention In order to achieve the above object, the resin lining construction method of a butterfly valve according to the present invention includes a casing, a pair of upper and lower valve shafts that penetrate the casing and are located on a common rotation axis, and these valve shafts. A resin lining construction method for a butterfly valve consisting of a valve body attached between the inner ends of the casing and a sealing member attached to the outer periphery, from the inner surface of the casing to the connecting flange contact surface and the vicinity of the valve shaft penetration part. lining with resin, and after lining,
a sealing member contacting portion, a connection flange contacting surface,
Apply a mold to the valve shaft penetration part and harden the resin.
Another method is to line the valve body with resin near the annular groove for attaching the seal member, and then apply a mold to harden the resin.

Embodiment and Operation An embodiment of the present invention will be described below based on FIGS. 4 to 9. In FIGS. 4 to 6, 20 is a cylindrical casing, which is composed of an upper casing 21A and a lower casing 21B each having a half-cylindrical shape. These upper casing 21A and lower casing 21
B has connecting flanges 22A and 22B on both end faces for connection with other piping, and is connected to each other via fixing tools 23 such as bolts and nuts on opposing parts on both sides. It has coupling flange parts 24A, 24B. Further, near the center in the circumferential direction and the longitudinal direction, valve shaft insertion holes 25A, 2 in the direction orthogonal to the casing axis are provided.
5B are formed, and these valve shaft insertion holes 25A, 25
Ring plate portions 26A and 26B are integrally formed at the outer end portion of B. The internal flow path formed by the casing 20 has a small diameter on the upstream side and a large diameter on the downstream side, so that the valve shaft insertion hole 25A,
There is a stepped portion 27A slightly upstream of the internal opening of 25B.
28B is formed. The upper casing 21A and the lower casing 21B are made of metal, in particular iron, and are also symmetrical, allowing for cheap manufacture and compatibility. The valve shaft insertion hole 25A,
25B is formed to have a small diameter on the inside and a large diameter on the outside, and a bearing mechanism or the like (described later) is attached to the large diameter portion. Both casings 21A, 2
Resin linings 28A, 28B are laminated on the inner surface of 1B, and these resin linings 28A, 28
B has a connecting flange portion 22A at the outer end,
22B, and in the valve shaft insertion holes 25A and 25B, it is integrally laminated from the small diameter part to the stepped part formed between the small diameter part and the large diameter part. . Resin lining 28
A, 28B [The same applies to the resin lining of each member described later. ] is made of reinforced resin containing reinforcing fibers (FRP), epoxy resin, acrylic resin, polyester resin, etc., and the same material can be used for each member, or different materials can be used. Further, resin linings 29A and 29B are laminated on the remaining parts of the outer surfaces of both casings 21A and 21B (excluding the large diameter portion of the valve shaft insertion hole). Note that when the two casings 21A, 21B are joined, a sealing member 30 containing a silicone adhesive is interposed between the mutually contacting surfaces of the resin linings 28A, 28B near the joining flanges 24A, 25B. Resin metals 31A, 31B are inserted into the large diameter portions of the valve shaft insertion holes 25A, 25B, respectively, and these resin metals 31A, 31B are inserted into the press-fitted resins 32A, 32.
By curing B, it is attached to both casings 21A and 21B. The resins 32A and 32B (the same applies to the press-fit resin described later) are made of epoxy resin or polyurethane resin, and when epoxy resin is used here and nylon is used as the resin metals 31A and 31B, both are Since the resin metals 31A and 31B can be replaced easily, the resin metals 31A and 31B can be easily replaced. 33A and 33B are valve shafts that can be inserted into and removed from the resin metals 31A and 31B, and a resin lining 34 is provided on the outer peripheral surface except for the inner end.
A and 34B are laminated and are rotatable on a common rotation axis 35. Both valve shafts 33A, 33B
is made of metal, and a mounting portion 36 for mounting a rotation operating tool (not shown) is integrally molded on the upper valve shaft 33A. Reference numerals 37A and 37B are annular sealing bodies made of resin or metal, which can be fitted into and removed from the large diameter portions of the valve shaft insertion holes 25A and 25B from the outside.
O-rings 38A, 38B that can freely come into contact with the outer surface of B
and 0 which can freely come into contact with the outer peripheral surfaces of the valve shafts 33A and 33B.
It has rings 39A and 39B. 40A, 40
B is a ring-shaped rubber seal plate, and seal body 37
It can be freely disposed between the outer surfaces of A, 37B and the annular portions 26A, 26B. Reference numerals 41A and 41B are ring-shaped holding plates made of metal and laminated with resin linings 42A and 42B on the entire surface, and can be fastened and fixed to ring plate parts 26A and 26B with fastening fixtures 43A and 43B. Become. Reference numeral 44 designates a disc-shaped valve body when viewed from the front, in which concave portions 45A and 45B that open outward are formed at two locations displaced by 180 degrees, and a concave portion 46 is provided between the concave portions 45A and 45B with a certain thickness. , approximately C in longitudinal section
It is formed in the shape of a letter. This valve body 44 is made of metal, and the entire surface is lined with resin 47.
are formed in layers. In the recesses 45A and 45B, the resin lining 47 is integrally formed at the entrance portion thereof. The valve shaft 33A,
The inner end of 33B fits into the recesses 45A and 45B,
Then, the press-fitted resins 48A and 48B are cured and integrated with the valve body 44. 49 is a resin press-in passage, 5
0 indicates a plug. A rubber seal member 51 is attached to the outer periphery of the valve body 44. Here, the sealing member 51 is made of NBR, CR, etc. whose rubber hardness is 50 or higher.
Manufactured in a ring shape from Viton, silicone, etc. A seal member 51 is provided on the outer periphery of the valve body 44.
An annular groove 52 for mounting is formed, and the resin lining 47 is integrally formed at the entrance of the annular groove 52. The valve body 44
A resin press-fitting passage 53 communicating with the inner part of the annular groove 52 is formed, and a silicon mold release material 54 is laminated inside the resin press-fitting passage 53 and the inner part of the annular groove 52. ing. 55 indicates a plug. The seal member 51 has both ends of its base, which is the part that fits into the annular groove 52, formed with serrated uneven surfaces 56 that provide a retaining effect. It is formed into two convex curved surfaces 57 that can freely come into contact with the valve abutment part A, which is formed by laminating resin linings 28A and 28B on the parts 27A and 27B. The number of threads (number of ridges) of this convex curved surface 57 is determined by the width D of the sealing member 51. For example, in the case of [D<20mm], there will be one strip,
If [20mm<D<40mm], there will be 2 strips. The seal member 51 can be attached to the valve body 44 by press-fitting a resin 58 into the annular groove 52 from the resin press-fitting passage 53 and hardening the resin 58. At this time, the sealing pressure (contact pressure) of the convex curved surface 57 against the valve abutting portion A is determined by the amount of press-in of the resin 58, but if the sealing pressure is twice the working pressure,
Press-fitting can be easily performed due to the relationship between the width S of the annular groove 52 and the working width d of the convex curved surface 57, and for example, press-fitting can be performed on-site. Note that the silicone mold release material 54 is used to facilitate replacement of the seal member 51.

Next, we will explain the manufacturing and assembly work. First, resin linings 28A and 28B are laminated on the inner surfaces of both casings 21A and 21B, which are manufactured in a symmetrical structure. At that time, as shown in FIG.
B. The inner open parts of the valve shaft insertion holes 25A and 25B are provided with molds 59, 60, and 6 according to the corresponding shapes, respectively.
These molds 59, 60, 61 are pressed against the resin linings 28A, 28B to mold them into predetermined dimensions and shapes, and the resin is cured. As a result, both casings 21A and 21B are
High accuracy can be obtained at the required locations even if the inner surface is not precisely machined. After that, both casings 2
Resin lining 2 for the outer surfaces of 1A and 21B
Lamination formation of 9A and 29B is performed without using a mold. Furthermore, the resin lining 47 can be laminated over the entire surface of the valve body 44, but in this case, the area near the opening of the annular groove 52 is covered with the mold 6.
Press molding is performed by 2. Valve shaft 33A, 33
Lamination of the resin linings 34A and 34B on B is performed using a bullet mold 63 to a predetermined size. Next, both the casings 21A and 21B are connected by the fixture 23, and the sealing member 30 is interposed at this time. Then, as shown in FIG. 8, the dummy shaft 64 is inserted between the valve shaft insertion holes 25A and 25B. This dummy shaft 64 includes the valve shafts 33A, 33 including the thickness of the resin linings 34A, 34B.
The outer diameter is made equal to B. The resin metals 31A, 31B are fitted onto the dummy shaft 64 inserted as described above, and these resin metals 31A, 31B are fitted into the large diameter portions of the valve shaft insertion holes 25A, 25B.
After adjusting and fixing the position of the dummy shaft 64 to a predetermined position relative to the casing 20,
Resin 32A on the outside of resin metal 31A, 31B,
32B and harden the resin metals 31A, 31B.
can be attached to the casing, 21A, 21B side.
As a result, the resin metals 31A, 31B can be arranged with high precision without machining the valve shaft insertion holes 25A, 25B with high precision. Next, after the dummy shaft 64 is extracted, the valve body 44 is fitted into the casing 20. At this time, the seal member 51 is fitted into the annular groove 52 of the valve body 44 . Recess 45
With the valve body 44 inserted in the position such that A and 45B face the valve stem insertion holes 25A and 25B, insert the valve stem 33 from the outside against the resin metals 31A and 31B.
A, 33B is inserted, and its inner end is inserted into the recess 45A,
45B. Then, while controlling the posture so that the valve body 44 is in the correct position, resins 48A and 48B are press-fitted into the recesses 45A and 45B through the resin press-fitting passage 49, and the resins 48A and 48B are
is cured to integrate both valve shafts 33A, 33B and the valve body 44. As a result, the recesses 45A and 45B
Even if the valve stems 33A and 33B are not machined with high precision,
and the valve body 44 can be coupled with high precision. Next, resin 58 is press-fitted into the annular groove 52 through the resin press-fitting passage 53, and when a predetermined sealing pressure is reached, the resin 58 is cured while the press-fitting is stopped, and the seal member 51 is attached to the valve body 44. Thereby, the sealing member 51 can be attached with a predetermined sealing pressure without machining the annular groove 52 with high precision. Note that the sealing member 51 can be fixed at the site as described above. Next, seal bodies 37A, 37B and rubber seal plate 40 are attached to both valve shafts 33A, 33B from the outside.
A, 40B and the holding plates 41A, 41B are fitted in this order, and the holding plates 41A, 41B are attached to the ring plate parts 26A, 26 using the tightening fixtures 43A, 43B.
Tighten and fix to B. The assembly is completed through the above steps, and the butterfly valve thus obtained is installed at a predetermined location in the pipeline and becomes operable.

During operation, the valve body 44 is opened and closed around the rotation axis 35 by operation via the mounting portion 36, thereby controlling the flow rate. When the valve body 44 is opened to the maximum as shown by the imaginary line in FIG. 4, the recessed portion 46 also becomes a flow path as shown in FIG. 5, thereby increasing the maximum flow rate. Fluid that tends to leak from the valve shaft insertion holes 25A, 25B during operation is prevented from leaking by the double seal structure of the seal bodies 37A, 37B and the rubber seal plates 40A, 40B. Seal body 37A, 37B
To replace the rubber seal plates 40A, 40B, loosen the tightening fixtures 43A, 43B and replace the holding plates 41A, 40B.
This can be done by removing the valve stems 33A and 33B from the resin metal 31.
Since it is supported by A and 31B, replacement can be performed even during operation. For repairs and inspections after stopping operation, remove the holding plates 41A, 41B, etc., remove the fixture 23, and then pull out each casing 21A, 22B from the valve stems 33A, 33B. This is made possible by This allows easy maintenance even though the valve shafts 33A, 33B and the valve body 44 are integrated.

Effects of the Invention According to the resin lining construction method for butterfly valves of the present invention, although the resin lining method is low in material cost, it requires precision at the seal member abutting portion, connecting flange facing surface, and valve shaft penetrating portion. In the annular groove for attaching the seal member, after lining with resin, a mold is applied and the resin is cured while molding (regulating) each surface.
High precision can be achieved without any machining in the necessary areas.

[Brief explanation of the drawing]

Figures 1 to 3 show conventional examples, and Figure 1 is the first example.
FIG. 2 is a vertical side view of the main part of the second conventional example, FIG. 3 is a vertical side view of the main part of the third conventional example, and FIGS. 4 to 9 are the main parts of the present invention. One embodiment is shown, FIG. 4 is a vertical side view, FIG. 5 is a vertical front view,
FIG. 6 is a longitudinal sectional view of the main part, and FIGS. 7 to 9 are longitudinal sectional views showing the state of manufacture and assembly. 20...Casing, 22A, 22B...Connection flange portion, 25A, 25B...Valve shaft insertion hole,
28A, 28B...Resin lining, 31A, 3
1B... Resin metal, 33A, 33B... Valve stem,
35...Rotation axis center, 37A, 37B...Seal body, 40A, 40B...Rubber seal plate, 44...
Valve body, 47... Resin lining, 51... Seal member, 52... Annular groove, 59, 60, 61, 62
... Molding mold, 63 ... Cylindrical mold, A ... Seal member contact portion.

Claims (1)

[Claims] 1. A casing, a pair of upper and lower valve shafts that pass through the casing and are located on a common rotation axis,
A resin lining construction method for a butterfly valve consisting of a valve body attached between the inner ends of these valve stems and a sealing member attached to the outer periphery, from the inner surface of the casing to the connecting flange contact surface and the valve stem penetrating part. The periphery is lined with resin, and after lining, a mold is applied to the seal member contact area, the connection flange contact surface, and the valve shaft penetration part to harden the resin, and the valve body is sealed. A resin lining construction method for butterfly valves in which the vicinity of the annular groove for attaching parts is lined with resin, and then a mold is applied to harden the resin.