JP3306371B2 - Piping joint for wafer type butterfly valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint connected to a piping system and attached to both end faces of a wafer type (thin type) butterfly valve having no flange on both sides.

[0002]

2. Description of the Related Art In a conventionally known wafer type butterfly valve, in which a seat ring is formed by bending the entire inner peripheral surface and both end surfaces of a main body, the bent portion slightly protrudes from the valve main body in the pipe axis direction. It is often used that the protrusion serves as a gasket only after the valve body is fastened via a long pipe bolt by a flange attached to the end of the pipe, and prevents external leakage of internal fluid pressure. I have. In addition, on the flange attached to the end of the above piping,
The pipes are integrated in advance by welding, screwing, or the like, and these are manufactured in a factory or on-site (site).

[0003] In a general piping system, a small diameter (50 A
The screw type (see Japanese Utility Model Application Laid-Open No. 4-68267) is often used, while the flange type is often used for those having a medium diameter (200A inside and outside).

[0004] In the case of the screw-in type, the end of the pipe is threaded (male thread) in advance, and an internally threaded flange is screwed into the male thread portion. Weld in advance,
Further, in the ring type, it is necessary to weld a predetermined ring to the end of the pipe, which requires a large number of steps and causes an increase in cost. Also, the prepared pipe length could not be used due to the situation at the site (site), and man-hours such as re-welding after cutting were required. Conversely, if it is too short, it cannot be used.

[0005] In recent piping systems for factories or building equipment, the use of a large amount of wafer type butterfly valves from small to medium and large diameters is due to its high reliability and small and lightweight piping (installation). ) It is thought to be due to advantages such as ease of construction. These methods employ a method in which the flanges are fixed to each other with pipe long bolts. However, there are problems due to a shortage of technicians involved in the welding operation, reliability of the welded portion, painting, and appearance. In particular, in order to make the piping system more convenient, it is said that it is necessary to review the connection joints, that is, the connections between pipes and pipes, pipes and valves, pipes and equipment, and the like.

Another problem in performing welding work on site is that a seat ring inserted into the butterfly valve is formed by joining and fixing a locally high-temperature flange surface after welding to both end surfaces of the butterfly valve. Troubles such as partial deterioration and burnout of the battery occur.

[0007] Also, from the corrosion resistance, durability and aesthetics of the piping system,
In some cases, the inner and outer surfaces of the valves, pipes, and joints are subjected to rust prevention treatment, powder coating, or the like. For this purpose, a single shape including the joints is required and the number of parts must be reduced. (For example, thread parts are a problem for piping bolts.)

Japanese Utility Model Laid-Open Publication No. Sho 54-174021 discloses a means for sealing and connecting a pipe connection end of a wafer type butterfly valve with a separate body such as a tightening band.

Japanese Unexamined Utility Model Publication No. 4-68267 also discloses a means for fixing a pipe connection end to a pipe connection member in advance by screwing or welding.

[0010] In all of these, it is necessary to preliminarily perform secondary processing (ring welding, flange welding, thread cutting, etc.) on the end of the pipe, resulting in a large number of man-hours and an increase in cost.

[0011]

As described above, in the prior art, both ends need to be fastened and fixed by flanges regardless of the diameter of the wafer type butterfly valve, and the joint with the pipe is integrated by welding. In general, man-hours are increased due to local (field) production, causing reliability problems and cost increases.

In addition, the joining of the flange and the pipe as described above requires a high degree of skill as a welding operation such as the right angle / parallelism, the degree of adhesion / airtightness of the end of the pipe, outer diameter / aesthetic appearance, etc. Workability is significantly affected by the working environment, welding position, high and low places, etc.

In consideration of the thermal stress during welding, the dimensional accuracy is strict and it is necessary to provide a relief area for the final welding point in the pipe length. The work is extremely inefficient and the working environment is not always favorable.

Further, when the connection portion of the piping system becomes a flange, the connection is made by bolts and nuts. For example, according to JIS standards, JIS5K, JIS10K, JIS
In the case of 16K, the predetermined size and quantity are different for each diameter, and unless a large number of bolts and nuts are tightened uniformly over the entire circumference of the flange, external leakage of fluid pressure due to single tightening will result.

[0015] In order to cope with the above problems, a technique has been disclosed in which the joint between the flange and the pipe is fixed by a method (means) other than welding. That is, in the joint in which the butterfly valve is interposed between the pipes, one of the joint bodies, which is in pressure contact with the end face of the wafer-type butterfly valve via a gasket, has a cylindrical shape in which the pipe is fitted. The outer surface projects a plurality of protrusions formed of a spiral surface, and a plurality of screw holes are obliquely drilled near the outer end surface, and a locking screw to be screwed with the screw hole is provided. The other joint body to be pressed is also cylindrical, and has a ridge provided on the outer periphery of the inner end face, and a plurality of screw holes are obliquely formed near the outer end face thereof and screwed with the screw holes. The engagement ring, which has a locking screw and is commonly engaged with both joint bodies, has a plurality of claws formed by cutting a groove formed by a spiral surface having an inner surface engaged with the spiral surface on the outer periphery of the ring. ,
Furthermore, projecting projections are respectively provided on the outer periphery of the claw,
A joint of a butterfly valve having an inner surface that is pressed against the outer surface of the ridge over the entire circumference of the ring has been disclosed (JP-A-7-833).
No. 41).

However, the joint body abuts on both side surfaces of the wafer-type butterfly valve, and a projection having a spiral surface formed on a peripheral surface of an inner end of one joint body and the other joint body. The protrusion formed on the outer surface of the inner end of the end portion is rotated by an engagement ring having a claw that is screwed with the spiral surface, whereby the protrusion of one joint main body and the engagement ring are rotated. The claw exerts the same action as tightening the screw, the other joint body is crimped on the inner surface of the engagement ring and the entire circumference, and the three members are joined together with the butterfly valve in between. However, the two joint bodies and the outer peripheral surface of the pipe are diagonally connected to the outer peripheral surface of the pipe by diagonally screwing a locking screw near the outer end surface of both joint bodies to generate extreme pressure at the screw tip. It is configured to bite locally and to firmly engage the surface.

According to the present invention, a wafer-type butterfly is formed by fixing a joint between a flange and a pipe by a method (means) other than welding, allowing an eccentric angle (centering) and expansion and contraction with the pipe by a relatively simple structure. It is an object of the present invention to provide a pipe joint that reliably seals both pipe connection surfaces of a valve.

[0018]

In order to solve the above-mentioned problems, a means adopted by the present invention is to fix a seat ring made of an elastic sealing member on the entire inner peripheral surface and a pipe connection surface of a valve body made of a rigid material. Then, in a wafer-type butterfly valve in which a disc-shaped valve body whose outer peripheral surface comes into contact with and separates from the seat ring is rotatably supported in the valve body, the two pipe connection surfaces of the wafer-type butterfly valve body are respectively provided. The end face of the joint body in which a flange-shaped pipe connection part and a cylindrical part having a larger diameter than the pipe are integrally formed at the ends is abutted, and the valve body and the two joint bodies are fastened and fixed with long bolts. At the other end of the main body, an endless packing having a cross-sectional shape having inclined surfaces on both sides is inserted into the outer peripheral surface of the pipe, and the packing is formed on one inclined surface on the valve body side at the other end of the joint body. Abut the slope,
The other inclined surface of the packing is brought into contact with a packing presser having surfaces that respectively contact the outer peripheral surface of the packing and the other inclined surface, and the outer surface of the inclined surface formed at the other end of the joint body and The packing is separated by a split band having an inclined surface which is in contact with the outer surface of the inclined surface of the packing retainer on the inner side, through the inclined surface portion at the other end of the joint body and the inclined surface portion of the packing retainer. In addition, an inner diameter enlarged portion larger than the pipe outer diameter is formed on the inner peripheral surface of the cylindrical portion of the joint main body, and the valve main body inner peripheral surface is formed at the valve body side inner end of the inner diameter enlarged portion. of forming a reduced diameter portion of inner diameter equal to the diameter of the seat ring, the pipe end portion
Is designed so that it does not overload the seat ring end face.
It is characterized in that was.

The inner and outer peripheral surfaces of the pipe joint are made of a rust-proofing or corrosion-resistant material. The pipe joint of the pipe joint with the valve body is formed in a hexagonal shape, and the long bolt is formed. The number is adapted to the shape.

Further, a reduced diameter portion is provided at the base of the inclined surface portion at the other end of the joint body which abuts on the valve body side surface of the endless packing inserted into the outer peripheral surface of the pipe. It is characterized by being formed slightly larger than the outer diameter.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the embodiments shown in the drawings. FIG. 1 is a front view of a pipe joint of a wafer type butterfly valve of the present invention. The left half from the valve stem center line is an outline view, and the right half is a cross-sectional view. FIG. 3 is a view taken on line II of FIG.
II-III line arrow view, FIG. 5 is an enlarged view of a main part of the part A of FIG.
FIG. 7 is an enlarged sectional view of a main part of a portion B in FIG.

In FIG. 1, a seat ring 2 made of an elastic material is mounted on an inner peripheral surface of a main body (valve main body) 1 of a wafer type butterfly valve, and a disc whose outer peripheral surface comes into contact with and separates from the seat ring 2 when opened and closed. A valve body 3 is attached to a valve stem 5 by a tapered bolt 4. As shown in FIG. 8, the seat ring 2 is mounted so that the compression allowance C protrudes from both ends of the main body 1. The amount of protrusion of the compression allowance C varies depending on the valve diameter, the material and hardness of the seat ring, etc., but is generally about 1 to 3 m / m. In this type of butterfly valve, it is not necessary to use a gasket packing, and it is possible to reduce the inconvenience of inserting the gasket packing in the installation work and to save materials.

In the present invention, as a connecting means between the valve body 1 and the pipe 6 described above, the valve body 1 is connected via the joint body 7.
The joint body 7 has a flange-like pipe connection portion 7a for clamping the valve body 1 to both ends of the valve body from both sides and integrally fixing the valve body 1 with long bolts 8. And an intermediate cylindrical portion 7b having a larger diameter than the pipe 6 at an intermediate portion, and a contact portion 7c at the other end with an endless packing 9 inserted into the outer peripheral surface of the pipe.

FIG. 7 shows one end of the joint body 7 on the valve body side.
As shown in the figure, the outer surface of the flange-shaped piping connection portion 7a has a piping connection surface 10 with the valve body 1 and presses against the compression allowance C of the seat ring 2 to perform a sealing action. Is formed with a reduced diameter 11 smaller than the pipe 6, and the intermediate cylindrical body 7 b forms an inner diameter enlarged portion 12 larger than the pipe 6. The end 13 is formed in a direction perpendicular to the central axis of the pipe 6,
The end of the pipe 6 is in contact with the inner end 13.

On the other hand, the other end 7c of the joint body 7 is
As shown in the figure, an endless (annular) packing 9 having inclined surfaces on both sides is inserted into the outer peripheral surface of the pipe 6.

FIG. 6 shows a state before the packing 9 is inserted into the pipe 6. In FIG.
Has a smaller diameter in the radial direction than the outer diameter of the pipe, so that the inner peripheral surface D of the packing and the outer peripheral surface D of the pipe come into close contact by being inserted.

The inclined surface E of the packing and the end inclined surface E of the joint body 7, the other inclined surface G of the packing and the inclined surface G of the packing presser fitting 14, and the outer peripheral surface F of the packing and the packing presser fitting 14 Under the condition that the inner peripheral surface F is in close contact, the inner peripheral inclined surface of the split band 15 is joined to the outer peripheral surface of the inclined surface, and is screwed to a predetermined position by a fastening bolt 16 (shown in FIG. The packing 9 is press-fitted to the outer peripheral surface of the pipe via the presser fitting 14, and external leakage of fluid pressure from the portion can be reliably prevented.
Also, the inner peripheral surface (14-1) of the packing retainer 14 is pressed against the outer peripheral surface of the pipe, thereby preventing the pipe 6 from being pulled out (to the right in FIG. 5). Inner circumference (14
By making -1) uneven and comb-shaped, the effect of preventing extraction can be obtained.

In FIG. 2 (view taken along the line II-II in FIG. 1), the pipe connecting portion 7a corresponding to the pipe flange is square when the valve diameter is small or medium (about 40 to 200 A). Also, the pipe mounting long bolts 8 are formed in a hexagonal or circular shape, and similarly, the number of the pipe mounting long bolts 8 is correspondingly large, and there is no external leakage of fluid pressure from the portion with sufficient strength to tighten the protruding portion of the seat ring. 1 and 2, 1a is a mounting flange of an actuator (not shown), 1b is a bottom plug, 1c is a gland packing, and 5a is an implantation key.

Next, the function and effect of the above embodiment will be described. As shown in FIG. 5, the inner diameter 7-1 of the joint body 7 is formed to have a slightly larger diameter than the outer diameter of the pipe 6, thereby stabilizing the pipe in the diametric direction and noise due to vibration of the piping system. Prevention can be performed.

Further, as shown in FIG. 7, by forming the inner diameter enlarged portion 12 in the cylindrical portion 7b of the joint main body 7, the eccentric tolerance at the time of piping of the pipe 6 is absorbed.
Also, although there is a difference in the valve diameter, the eccentric angle can be absorbed up to about ± 3 °.

Further, by providing the inner end portion 13 (FIG. 7) of the joint body, the deepest (rear) portion when the pipe 6 is inserted is determined. Irrelevant, and there is no strong pressure on the end face of the seat ring 2, and the safety and ease of piping work can be improved.

The eccentric angle of the pipe and the expansion and contraction (length) of the pipe as described above are suitable for preventing vibration of the piping system or shaking due to an earthquake or the like, and preventing stress concentration and breakage of the piping system. it can.

FIG. 4 shows another embodiment of FIG.
One end of the split type band 15 is a ring (hinge type) 16a, and the same operation and effect as those shown in FIG.
Mainly suitable for small diameter valves.

Next, rust prevention or powder coating of the inner and outer surfaces of valves, joints, pipes, etc. is increasing due to corrosion resistance, durability, aesthetics, etc. of the piping system. Have come.

In the piping system, corrosion resistance must be ensured so that fluid does not come into contact with metal parts on the inner peripheral surface of the pipe.
Nylon powder coating may be applied to the inside and outside of the pipe in consideration of the weather resistance to the environment. This powder coat has excellent chemical properties, has excellent adhesion to metal, and can be used up to 80 ° C in fluid specification temperature. It is often used, so that painting work after piping is unnecessary, and total cost can be reduced. Another method is an epoxy resin powder coating.

Note that, as a precautionary point in piping (installation) work, chamfering the corner of the pipe tip and removing impurities and the like near the packing insertion portion leads to leakage prevention after insertion. .

[0037]

As described above, according to the present invention,
A seat ring made of an elastic sealing member is fixed on the entire inner peripheral surface and the pipe connection surface of the valve body made of a rigid material, and a disc-shaped valve body whose outer peripheral surface comes into contact with and separates from the seat ring is rotatable. A joint in which a flanged pipe connection portion and a cylindrical portion having a larger diameter than the pipe are integrally formed at both ends of the pipe connection surfaces of the wafer type butterfly valve body, respectively. The end face of the main body is abutted, the valve main body and both joint main bodies are fastened and fixed by long bolts, and endless packing having a cross-sectional shape having inclined surfaces on both sides is inserted into the outer peripheral surface of the pipe at the other end of each of the joint main bodies. Attachment, one inclined surface on the valve body side of the packing is brought into contact with the inclined surface formed at the other end of the joint main body, and the outer peripheral surface of the packing and the other inclined surface are formed on the other inclined surface of the packing. A pad that has a surface that contacts each The split type band in which the kin presser fitting is abutted and the inclined surface formed on the inner surface of the inclined surface formed on the other end of the joint main body and the outer surface of the inclined surface of the packing retainer is formed on the inner side. The packing is fastened to the pipe peripheral surface via the inclined surface portion of the other end of the joint body and the inclined surface portion of the packing presser, and further, the inner diameter enlarged by making the inner peripheral surface of the cylindrical portion of the joint body larger than the pipe outer diameter. A reduced diameter portion having the same diameter as the inner diameter of the seat ring on the inner peripheral surface of the valve body is formed at the inner end of the valve body side of the enlarged inner diameter portion, and the end of the pipe is the end surface of the seat ring. Strong
The following effects can be provided by the configuration in which no pressure is applied .

[0038] (i) by fastening fixed by each of the two pipe connecting surface of the wafer-shaped butterfly valve body end face of the fitting body 4-6 pieces of long bolts, working by attaching fastening parts without requiring skilled workers Can be completed. In addition, by fixing the joint body integrated with the cylindrical portion to both end surfaces of the wafer-type butterfly valve body by bolting before the piping work, the mounting work at the site (site) is remarkably improved.

(Ii) An endless packing is inserted into the outer peripheral surface of the pipe, and a split type trapezoidal band is fastened through a packing retainer to prevent fluid leakage from the pipe without damaging the outer peripheral surface of the pipe. can do. At this time,
By pressing the inner peripheral end of the packing retainer against the outer peripheral surface of the pipe, the pipe can be prevented from coming off.

(Iii) By providing the inner diameter enlarged portion on the inner surface of the cylindrical portion of the joint main body, it is possible to absorb the eccentric tolerance during piping.

(Iv) By providing a reduced diameter portion on the inner diameter end face of the joint main body, it is possible to push the pipe into the pipe at the time of inserting the pipe, thereby preventing pressure from being strongly applied to the seat ring end face. There is no abnormality in the rotation of.

(V) Since secondary processing such as ring welding, flange welding, and thread cutting at the pipe end is not required, equipment for a welding machine and a thread cutting machine is not required, and a great number of man-hours can be reduced. Since welding work on site (site) is not required, burnout of the seat ring, packing, and the like due to spatter can be prevented, and contamination of impurities into the pipe can be prevented.

Further, since the inner and outer peripheral surfaces of the joint main body are made of a rust-proofing or corrosion-resistant material, it can be used stably for a long period of time, and painting and the like are not required, so that the cost can be reduced.

Further, a reduced diameter portion is provided at the base of the inclined surface portion at the other end of the joint body which abuts on the valve body side surface of the endless packing inserted into the outer peripheral surface of the pipe, and the inner diameter of the reduced diameter portion is determined by the packing. By being formed slightly larger than the outer diameter, it is possible to stabilize the pipe in the diameter direction and to prevent noise due to vibration of the piping system.

[Brief description of the drawings]

FIG. 1 is a front view of a pipe joint of a wafer type butterfly valve showing one embodiment (example) of the present invention, wherein a left half of a valve stem center line is an outline view and a right half is a cross-sectional view.

FIG. 2 is a view taken along the line II-II in FIG.

FIG. 3 is a view taken along the line III-III in FIG. 1;

FIG. 4 is a view showing another embodiment of FIG. 3;

FIG. 5 is an enlarged sectional view of a main part of a portion A in FIG. 1;

FIG. 6 is an exploded view of FIG. 5 showing sealing of the packing.

FIG. 7 is an enlarged sectional view of a main part of a portion B in FIG. 1;

FIG. 8 is an explanatory view of sealing a seat ring.

────────────────────────────────────────────────── ─── Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 1/16-1/226 F16K 27/00-27/12 F16L 21/00-23/04

Claims (4)

(57) [Claims] A seat ring made of an elastic sealing member is fixed on the entire inner peripheral surface and a pipe connection surface of a valve body made of a rigid material, and a disk-shaped valve body whose outer peripheral surface comes into contact with and separates from the seat ring is rotated. In a wafer type butterfly valve movably pivotally supported in a valve body, a flange-like pipe connection portion and a cylindrical portion having a larger diameter than a pipe are provided at both ends on both pipe connection surfaces of the wafer type butterfly valve body. The end faces of the integrally formed joint body are abutted, the valve body and both joint bodies are fastened and fixed by long bolts, and the other end of each of the joint bodies is provided with an endless packing having a cross-sectional shape having inclined surfaces on both sides. The packing is inserted into the outer peripheral surface, and one inclined surface of the packing on the valve body side is brought into contact with the inclined surface formed at the other end of the joint body, and the other inclined surface of the packing is attached to the outer peripheral surface of the packing. Surface and the other inclined surface respectively A split type band in which an inclined surface formed on the inner surface of the inclined surface formed at the other end of the joint body and an outer surface of the inclined surface of the gasket retainer are formed on the inner side of the joint body. By
The packing is fastened to the pipe peripheral surface via the inclined surface portion of the other end of the joint body and the inclined surface portion of the packing presser, and further, the inner diameter of the inner peripheral surface of the cylindrical portion of the joint body is made larger than the outer diameter of the pipe. An enlarged portion is formed, and the inner diameter of the seat ring on the inner peripheral surface of the valve body is provided at the inner end of the valve body on the inner side of the valve body.
The diameter of the pipe is equal to the diameter of the pipe.
A piping joint for a wafer-type butterfly valve, wherein the piping joint is configured so as not to be strongly pressed to the end face . 2. A pipe joint for a wafer type butterfly valve according to claim 1, wherein the inner and outer peripheral surfaces of the pipe joint are made of a rust-proof or corrosion-resistant material. 3. The pipe connection part of the pipe joint with the valve body is 4 to
The piping joint of a wafer type butterfly valve according to claim 1 or 2, wherein the pipe has a hexagonal shape, and the number of long bolts matches the shape. 4. A reduced diameter portion is provided at the base of an inclined surface portion at the other end of the joint body which abuts on the valve body side surface of the endless packing inserted into the outer peripheral surface of the pipe, and the inner diameter of the reduced diameter portion is determined by the pipe diameter. 2. The structure according to claim 1, wherein the outer diameter is slightly larger than the outer diameter.
4. A piping joint for a wafer-type butterfly valve according to any one of claims 3 to 3.