JP2018059561A - Pipe joint and backflow preventer unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint which is easy in the removal and attachment of an apparatus having a piping connection flange with respect to piping.SOLUTION: A first pipe joint 6 for connecting a backflow preventer 7 and piping has a pipe part 31, a flange part 32 located at an external peripheral side of the pipe part 31 in a movable state movable to a pipe axial direction X, and a snap ring 33 for fixing the flange part 32 to a fixed position A of the pipe part 31. An end face of the flange part 32 in a second direction X2 is a flange abutment face 32a, and in a state that the flange part 32 is fixed to the fixed position A, the flange abutment face 32a is located ahead of the pipe part 31 by a gap G. The first pipe joint 6 fixes the flange part 32 to the fixed position A, makes the flange part 32 abut on a first piping connection flange 18 of the backflow preventer 7, and is connected to the backflow preventer 7. When moving the flange part 32 by releasing the snap ring 33, the gap G is formed between the first pipe joint 6 and the backflow preventer 7.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pipe joint that connects a valve having a flange for pipe connection and a pipe such as a water pipe. Moreover, it is related with a backflow preventer unit provided with a pipe joint and a backflow preventer.

  Patent Document 1 discloses a backflow preventer that is installed in the middle of a water supply pipe to a building, a condominium, or the like and prevents a backflow of water when the water supply pressure is lowered. The backflow preventer of Patent Document 1 includes a pair of cylindrical portions that communicate with the valve chamber on both sides of the valve chamber that houses the valve body. One cylinder part is connected to the primary side pipe, and the other cylinder part is connected to the secondary side pipe.

  A valve including a flange for pipe connection is described in Patent Document 2. The valve of Patent Document 2 has a valve chamber that houses a valve body, and a pair of pipe connection flanges provided on both sides of the valve chamber. The flange end surfaces of the pipe connection flanges located on the opposite side of the valve chamber are parallel to each other, and each flange end surface is provided with a fluid flow port communicating with the valve chamber. Here, a device such as a valve having a pipe connection flange is connected to the pipe via a pipe joint having a flange portion that comes into contact with the flange end face of the pipe connection flange. The flange portion of the pipe joint and the flange for pipe connection are fastened by fastening bolts or the like.

JP 2003-14147 A JP 05-248562 A

  When a device such as a backflow preventer or a valve is about to be replaced or has failed, it may be necessary to remove the device from the pipe depending on the situation. Here, as in Patent Document 2, when the equipment includes a pipe connection flange, the fastening by the fastening bolt between the pipe connection flange and the flange portion of the pipe joint is released, and the equipment is connected to the pipe of the pipe. By pulling out in the direction orthogonal to the axial direction, the device can be removed from between the pipe joints.

  However, a seal member such as packing is usually inserted between the pipe connection flange of the device and the flange portion of the pipe joint in order to make the space between them liquid-tight. Further, the seal member is in an elastically compressed state between them. Therefore, when the device is moved in the direction orthogonal to the tube axis direction, the seal member acts as a load, and it is difficult to remove the device from between the pipe joints. In addition, when installing a new device between the pipe joints that are fixed at the front and rear, the new device must be inserted between the pipe joints together with a seal member having a compression allowance, which is difficult to insert. is there.

  The subject of this invention is providing the pipe joint which removes an apparatus provided with the flange for piping connection from piping, and is easy to attach to piping in view of such a point. Moreover, it is providing the backflow preventer unit provided with such a pipe joint and a backflow preventer.

In order to solve the above-described problems, the present invention provides a pipe joint disposed between a device having a pipe connection flange and a pipe to connect the device and the pipe. An annular flange portion positioned on the outer peripheral side of the tube portion so as to be movable in the axial direction, and a fixture that is detachably attached to the tube portion and fixes the flange portion at a predetermined fixing position in the tube portion. The pipe portion includes a connection portion that connects the pipe to an end portion in the first direction of the tube axis direction, and the flange portion is in a second direction opposite to the first direction. An end surface is a flange contact surface that can contact the pipe connection flange, and in a state where the flange portion is fixed at the fixed position, the flange contact surface is more than an end of the pipe portion in the second direction. Is also located forward.

  The pipe joint of the present invention connects equipment and piping in a state where the flange portion is fixed to the fixing position of the pipe portion by a fixture. On the other hand, when the device is removed from the pipe, the fixture is removed from the pipe portion, and the flange portion is moved in the first direction (a direction away from the device in the tube axis direction).

  Here, in a state in which the flange portion is fixed at the fixed position, the flange contact surface of the flange portion is located in front of the end in the second direction (end on the device side) in the pipe portion. Therefore, when the pipe joint and the device are connected using the flange portion, the pipe portion and the device do not contact each other, and the flange portion is moved in the first direction so that the flange contact surface is positioned more than the end of the tube portion. When positioned on one side, a gap is formed between the pipe joint and the device. Therefore, when removing the device from the pipe, the device can be moved in the tube axis direction by this gap. Therefore, it becomes easy to remove the device from the pipe. In addition, when a seal member such as packing is inserted between the flange for pipe connection of the equipment and the flange part of the pipe joint, the fixture pipe is removed and the flange part is moved in the first direction to remove the pipe of the equipment. Since a gap is formed between the connecting flange and the flange portion of the pipe joint, the seal member is released from the compressed state. Therefore, the seal member can be prevented or suppressed from acting as a load when the device is moved in a direction orthogonal to the tube axis direction.

  In addition, when installing equipment with a pipe connection flange between pipe joints with fixed front and rear, it is assumed that the fixture is removed from the pipe part of the pipe joint and the flange part is moved in the first direction. Insert equipment between fittings. Thereafter, the flange portion is moved in the second direction and fixed at a fixed position by a fixture, and the flange for pipe connection of the device and the flange portion of the pipe joint are brought into contact with each other. Here, in the state where the flange portion is moved in the first direction, the total length of the pipe joint is shorter than in the state where the flange portion is fixed at the fixed position. Thereby, since the space | interval between pipe joints becomes long, it becomes easy to insert an apparatus between pipe joints. Moreover, even when it inserts between an apparatus and a pipe joint with the sealing member provided with a compression allowance, the insertion becomes easy. Therefore, it becomes easy to attach the apparatus provided with the flange for pipe connection to the pipe.

  In the present invention, in order to position the flange contact surface in front of the end of the pipe portion in the second direction, the pipe portion includes a protrusion projecting to the outer peripheral side, and the protrusion in the first direction. A fixing device mounting portion provided at a spaced position, and the flange portion includes a notch recess extending in the first direction from the flange contact surface on an inner peripheral surface thereof, and the fixing device includes the fixing device In a state where the flange portion is fixed to the fixing position by being mounted on the fixing device mounting portion, the protrusion is inserted into the notch recess and comes into contact with the inner wall surface in the first direction in the notch recess, It is desirable that the fixture comes into contact with the flange portion from the first direction side.

  In the present invention, an O-ring may be provided, and the tube portion may include an annular groove between the protrusion and the fixture mounting portion, and the O-ring may be attached to the annular groove at the fixed position. It is desirable to interpose between the flange portion and the pipe portion arranged. If it does in this way, when a flange part is fixed to a fixed position, between a flange part and a pipe part can be made fluid-tight.

In the present invention, the fixture is preferably a metal retaining ring having a C-shaped portion. In this way, it becomes easy to detachably attach the fixing portion to the outer peripheral side of the tube portion.

  In the present invention, an annular packing is provided, the flange portion includes an annular projecting portion that surrounds the tube portion and projects in the second direction, and a distal end surface of the annular projecting portion is the flange contact surface. In addition, the packing may be held by the flange portion in a state where the annular projecting portion is inserted into the center hole. If it does in this way, between the flange for piping connection of an apparatus and the flange part of a pipe joint can be made fluid-tight by packing.

  In this invention, it has a 2nd O-ring, The annular groove surrounding the said pipe part is formed in the said flange contact surface, The said 2nd O-ring is mounted | worn with the said annular groove. Can be. If it does in this way, between the flange for pipe connection of an apparatus and the flange part of a pipe joint can be made fluid-tight with a 2nd O-ring.

  Next, a backflow preventer unit according to the present invention includes the above-described pipe joint, a backflow preventer, and a fastener for fastening the pipe joint and the backflow preventer. A valve chamber that houses the valve body, a first pipe connection flange and a second pipe connection flange provided on both sides of the valve chamber, and the valve chamber of the first pipe connection flange Is opened at the first flange end face located on the opposite side and communicated with the valve chamber, and opened at the second flange end face located on the opposite side of the second pipe connection flange from the valve chamber. A fluid outlet port that communicates with the valve chamber, wherein the first flange end surface and the second flange end surface are parallel to each other, and the fastener is fixed to the fixing position of the flange portion. The flange contact surface and the first flange end surface or the second flange Characterized by detachably fastening the said backflow preventer and the pipe joint being in contact with a di-end face.

  According to the present invention, a gap can be provided between the pipe joint and the backflow preventer by removing the fixture from the pipe part and moving the flange part in the pipe axis direction in a direction away from the device. Therefore, it is easy to remove the backflow preventer from the backflow preventer unit in a state where the backflow preventer unit is installed in the middle of the pipe.

  In the present invention, the pipe joint includes an annular packing, the flange portion includes an annular projecting portion that surrounds the tube portion and projects in the second direction, and a distal end surface of the annular projecting portion It is a flange contact surface, and the packing is held by the flange portion in a state where the annular projecting portion is inserted into the center hole thereof, and the pipe joint and the backflow preventer are fastened by the fastener. In this case, the packing can be elastically deformed between the flange portion and the backflow preventer to make the space between the pipe joint and the backflow preventer liquid-tight. If it does in this way, it can prevent that a fluid leaks from between a pipe joint and a backflow preventer. Even when the packing is interposed between the backflow preventer and the pipe joint, the packing can be released from the compressed state by moving the flange portion of the pipe joint from the fixed position. Therefore, when removing the backflow preventer from the backflow preventer unit, it is possible to prevent or suppress the packing from acting as a load. Moreover, if the flange part of a pipe joint is moved from a fixed position, the full length of a pipe joint will become short compared with the state where the flange part is being fixed to the fixed position. Therefore, it becomes easy to interpose the packing having the compression allowance between the pipe joint and the backflow preventer.

In the present invention, it comprises a second O-ring interposed between the pipe joint and the backflow preventer to make the space between the pipe joint and the backflow preventer liquid-tight, and the first flange end face is A first annular groove surrounding the fluid inlet; and a second flange end surface including a second annular groove surrounding the fluid outlet; the first annular groove or the second annular groove includes A second O-ring can be attached. If it does in this way, it can prevent that a fluid leaks from between a pipe joint and a backflow preventer. Even when the second O-ring is interposed between the backflow preventer and the pipe joint, the second O-ring can be released from the compressed state by moving the flange portion of the pipe joint from the fixed position. Therefore, when removing the backflow preventer from the backflow preventer unit, the second O-ring can be prevented or suppressed from acting as a load. Moreover, if the flange part of a pipe joint is moved from a fixed position, the full length of a pipe joint will become short compared with the state where the flange part is being fixed to the fixed position. Therefore, it becomes easy to interpose the second O-ring having the compression allowance between the pipe joint and the backflow preventer.

  In this invention, it has a water stop cock which connects the said pipe joint and the said piping between the said pipe joint and the said pipe, and the said water stop cock is connected to the connection part of the pipe part of the said pipe joint. It is desirable. If it does in this way, when removing a backflow preventer from a backflow preventer unit, it is possible to close the stop cock and prevent water from flowing through the backflow preventer unit.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes easy to remove apparatuses, such as a backflow preventer provided with the flange for piping connection, from piping.

It is the top view and front view of a backflow preventer unit to which the present invention is applied. It is the back of a 1st pipe joint, a side view, and a front view. It is a side view of the 1st pipe joint in the state where the flange part was moved. It is explanatory drawing of the removal method which removes a backflow preventer from piping. It is explanatory drawing of the pipe joint of a modification. It is explanatory drawing of the backflow preventer unit of a modification. It is explanatory drawing of the 1st pipe joint of the backflow preventer unit of a modification.

  Below, with reference to drawings, the backflow preventer unit which is embodiment of this invention is demonstrated.

(Backflow prevention unit)
Fig.1 (a) is a top view of the backflow preventer unit connected to piping, and FIG.1 (b) is the front view. The backflow preventer unit 1 is installed between a primary side pipe 2 and a secondary side pipe 3 of a water supply device to a building or a condominium, etc., from the secondary side pipe 3 side to the primary side pipe 2 side. Prevent backflow of water.

  As shown in FIG. 1 (a), the backflow preventer unit 1 includes a first ball stop cock (stop cock) 5, a first stop pipe 5 from the primary pipe 2 side to the secondary pipe 3 side. The pipe joint 6, the backflow preventer 7, the second pipe joint 8, and the second ball stop cock 9 are provided in this order. The backflow preventer unit 1 includes a first fastening bolt 10 that detachably fastens the first pipe joint 6 and the backflow preventer 7 and a second fastening joint 10 that detachably fastens the second pipe joint 8 and the backflow preventer 7. Two fastening bolts 11 are provided. The primary side pipe 2, the secondary side pipe 3, the first ball stop cock 5, the first pipe joint 6, the backflow preventer 7, the second pipe joint 8, and the second ball stop cock 9 are arranged coaxially. . In the following description, the direction along the tube axis L is defined as a tube axis direction X, the direction toward the primary side pipe 2 is defined as a first direction X1, and the opposite direction is defined as a second direction X2.

  The backflow preventer 7 is a decompression type backflow preventer. As shown in FIG. 1B, the backflow preventer 7 includes a first check valve 12, a second check valve 13, a relief valve 14, a differential pressure moving mechanism 15 that moves the relief valve 14, and these A valve chamber 17 is provided. The backflow preventer 7 includes a first pipe connection flange 18 and a second pipe connection flange 19 on both sides of the valve chamber 17 interposed therebetween.

The valve chamber 17 includes a primary side channel 17a, a secondary side channel 17b, a primary side channel 17a, and a secondary side channel 1
The intermediate chamber 17c between 7b and the discharge port 17d for discharging the water of the intermediate chamber 17c are provided. A first check valve 12 is arranged in the primary flow path 17a. The first check valve 12 allows the flow of water from the primary flow path 17a to the intermediate chamber 17c, and blocks the flow of water from the intermediate chamber 17c to the primary flow path 17a. A second check valve 13 is disposed in the secondary flow path 17b. The second check valve 13 allows the flow of water from the intermediate chamber 17c to the secondary flow path 17b and blocks the flow of water from the secondary flow path 17b to the intermediate chamber 17c. The differential pressure moving mechanism 15 moves the relief valve 14 in a direction toward and away from the discharge port 17d according to a pressure difference between the pressure in the primary channel 17a and the pressure in the intermediate chamber 17c. The differential pressure moving mechanism 15 opens and closes the discharge port 17d by the relief valve 14.

  The first pipe connection flange 18 has a square shape with rounded corners when viewed from the pipe axis direction X. Bolt fastening portions 18 a are provided at the four corners of the first pipe connecting flange 18. A fluid inflow port 21 communicating with the valve chamber 17 is opened on the first flange end surface 18 b located on the opposite side of the first pipe connecting flange 18 from the valve chamber 17. The fluid inlet 21 is an upstream end opening of the primary channel 17a. The second pipe connection flange 19 has a square shape with rounded corners when viewed from the pipe axis direction X. Bolt fastening through holes 19 a are provided at four corners of the second pipe connection flange 19. A fluid outlet 22 that communicates with the valve chamber 17 opens at the second flange end surface 19 b located on the opposite side of the second piping connection flange 19 from the valve chamber 17. The fluid outlet 22 is an opening at the downstream end of the secondary channel 17b.

  Here, the first flange end surface 18b and the second flange end surface 19b are each perpendicular to the tube axis L and parallel to each other. The fluid inlet 21 and the fluid outlet 22 are coaxial.

  As shown in FIG. 1B, the first flange end face 18b is provided with a first annular groove 23 surrounding the fluid inflow port 21. An O-ring 24 is detachably attached to the first annular groove 23. A second annular groove 25 surrounding the fluid outlet 22 is provided in the second flange end surface 19b. An O-ring 26 is detachably attached to the second annular groove 25.

  The first pipe joint 6 is disposed between the backflow preventer 7 and the first ball stopcock 5 to connect the backflow preventer 7 and the first ball stopcock 5. The first pipe joint 6 includes a pipe part 31, an annular flange part 32 positioned on the outer peripheral side of the pipe part 31 so as to be movable in the pipe axis direction X, and a detachable attachment to the pipe part 31. There is a retaining ring (fixing tool) 33 for fixing 32 to a predetermined fixing position A in the pipe part 31. The first pipe joint 6 has a connection portion 34 at the end portion of the pipe portion 31 in the first direction X1.

  The connection portion 34 of the first pipe joint 6 is screwed into the first ball stop cock 5. Further, in the first pipe joint 6, the end surface (flange contact surface 32 a) in the second direction X <b> 2 of the flange portion 32 is the first flange end surface 18 b of the backflow preventer 7 with the flange portion 32 fixed at the fixed position A. It is made to contact. The flange portion 32 is fastened to the backflow preventer 7 (first pipe connecting flange 18) by the first fastening bolt 10. Here, an O-ring 24 is interposed between the flange portion 32 of the first pipe joint 6 and the first pipe connection flange 18 of the backflow preventer 7. Accordingly, the first pipe joint 6 and the backflow preventer 7 are connected in a liquid-tight manner. Details of the first pipe joint 6 will be described later.

  The first ball stop cock 5 includes a lever 41 for driving a valve body 40 that opens and closes the internal flow path 5a. In the state shown to Fig.1 (a), the internal flow path 5a of the 1st ball stop cock 5 is an open state. Further, the ball stop cock has a strainer 42 therein. As for the 1st ball stop cock 5, the connection part 43 provided in the edge part of the 1st direction X1 is screwed in the edge part of the 2nd direction X2 of the primary side piping 2. As shown in FIG.

The second pipe joint 8 is disposed between the backflow preventer 7 and the second ball stop cock 9 so as to prevent the backflow preventer 7.
And the second ball stop cock 9 are connected. The second pipe joint 8 includes a pipe portion 45 and an annular flange portion 46 that protrudes from the end of the pipe portion 45 in the first direction X1 to the outer peripheral side. The tube portion 45 and the flange portion 46 are integral. The flange portion 46 has a square shape with rounded corners when viewed from the tube axis direction X. The contour shape of the flange portion 44 is the same as the contour shape of the second pipe connecting flange 19. In addition, bolt fastening portions 46 a are provided at the four corners of the flange portion 46. The second pipe joint 8 has a connection portion 47 at the end portion of the pipe portion 45 in the second direction X2.

  The connecting portion 47 of the second pipe joint 8 is screwed into the second ball stop cock 9. The second pipe joint 8 is connected to the backflow preventer 7 by the second fastening bolt 11 in a state where the end face 46b of the flange portion 46 in the first direction X1 is in contact with the second flange end face 19b of the backflow preventer 7. It is concluded. The second fastening bolt 11 is screwed into the bolt fastening portion 46a from the first direction X1 side through the bolt fastening through hole 19a of the second pipe connecting flange 19. Here, an O-ring 26 is interposed between the flange portion 46 of the second pipe joint 8 and the second pipe connection flange 19 of the backflow preventer 7. Accordingly, the second pipe joint 8 and the backflow preventer 7 are connected in a liquid-tight manner.

  The second ball stop cock 9 includes a handle 51 for driving a valve body 50 that opens and closes the internal flow path 9a. In the state shown to Fig.1 (a), the internal flow path 9a of the 2nd ball stop cock 9 is an open state. As for the 2nd ball stop cock 9, the connection part 52 provided in the edge part of the 2nd direction X2 is screwed in the edge part of the 1st direction X1 of the secondary side piping 3. As shown in FIG.

(1st pipe joint)
FIG. 2 is an explanatory view of the first pipe joint 6 of the present invention. FIG. 2A is a rear view when the first pipe joint 6 is viewed from the first direction X1, and FIG. 2B is a side view of the first pipe joint 6, and FIG. These are front views at the time of seeing the 1st pipe joint 6 from the 2nd direction X2 side. In FIG. 2B, the upper half of the first pipe joint 6 is a sectional view. FIG. 3 is a side view of the first pipe joint 6 in a state where the flange portion 32 is moved from the fixed position A in the first direction X1. In FIG. 3, the upper half of the first pipe joint 6 is a sectional view.

  As shown in FIG. 2, the first pipe joint 6 includes a pipe part 31, an annular flange part 32 positioned on the outer peripheral side of the pipe part 31 in a state that it can move in the pipe axis direction X of the pipe part 31, A retaining ring 33 is detachably attached to the pipe part 31 and fixes the flange part 32 to a fixing position A in the pipe part 31. FIG. 2 shows a state in which the flange portion 32 is fixed to the fixing position A by the retaining ring 33.

  The pipe part 31 is cylindrical and includes a connection part 34 that connects a pipe (first ball stop cock 5) to an end part in the first direction X <b> 1 in the pipe axis direction X. As shown in FIG. 2A, the connection portion 34 includes a pair of parallel surfaces 61 parallel to each other on both sides of the tube axis L therebetween. The pair of parallel surfaces 61 are connected by a pair of arcuate surfaces 62 with the tube axis L as the center. The pair of parallel surfaces 61 are used for hanging a wrench. The connecting portion 34 may further include a pair of parallel surfaces at an angular position that is 90 ° apart from the pair of parallel surfaces 61. That is, the connecting portion 34 may include two pairs of parallel surfaces for hanging the wrench.

  As shown in FIG. 2B, the pipe portion 31 includes an annular protrusion 64 having a constant width protruding toward the outer peripheral side at the front end edge in the second direction X2. In addition, the pipe portion 31 includes an annular fixture mounting recess (fixing device mounting portion) 65 for fixing the retaining ring 33 at a position away from the annular protrusion 64 in the first direction X1. Two annular O-ring mounting grooves 66 are provided in parallel between the annular projection 64 and the fixture mounting recess 65 in the tube axis direction X. Each O-ring mounting groove 66 is mounted with an O-ring 67.

  As shown in FIG. 2 and FIG. 3, the flange portion 32 includes a tubular portion 71 that surrounds the tubular portion 31 from the outer peripheral side, and an annular plate that extends from the front end portion of the tubular portion 71 in the radial direction perpendicular to the tubular axial direction X. Part 72 is provided. The end surface of the annular plate portion 72 in the second direction X2 is a flange contact surface 32a that can contact the first pipe connection flange 18.

  As shown in FIGS. 2A and 2C, the contour shape when the annular plate portion 72 is viewed from the tube axis direction X is a square having rounded corners. The contour shape of the annular plate portion 72 and the contour shape of the first pipe connection flange 18 are the same. Bolt fastening through holes 74 are provided at four corners of the annular plate portion 72.

  Further, as shown in FIG. 2B, the flange portion 32 includes a notch recess 75 extending in the first direction X1 from the end edge in the second direction X2 on the inner peripheral surface thereof. The notch recess 75 has an annular shape, and can accommodate the annular protrusion 64 of the pipe portion 31 on the inner peripheral side thereof.

  The retaining ring 33 is made of a metal such as stainless steel or phosphor bronze. As shown in FIG. 2A, the retaining ring 33 includes a C-shaped portion 78, a bent portion 79 that bends outward from each of the two open ends of the C-shaped portion 78, and an outward from the bent portion 79. An extending knob 80 is provided. The retaining ring 33 has a C-shaped portion 78 mounted on the fixing device mounting recess 65 from the outer peripheral side, and fixes the flange portion 32 to the fixed position A.

  Here, when the flange portion 32 is fixed at the fixing position A, the annular protrusion 64 of the tube portion 31 is accommodated in the notch recess 75, and the retaining ring 33 is mounted in the fixing device mounting recess 65. As a result, the annular protrusion 64 of the tube portion 31 contacts the inner wall surface 75a of the cutout recess 75 in the first direction X1, and the retaining ring 33 contacts the flange portion 32 from the first direction X1 side. Accordingly, the flange portion 32 is positioned and fixed at the fixed position A.

  In a state where the flange portion 32 is fixed at the fixing position A, the flange contact surface 32a is positioned forward by the gap G from the end (opening edge of the tube portion 31) 31a of the tube portion 31 in the second direction X2. Further, in a state where the flange portion 32 is fixed at the fixing position A, two O-rings 67 are interposed between the pipe portion 31 and the flange portion 32. Therefore, the space between the pipe portion 31 and the flange portion 32 is liquid-tight. The first pipe joint 6 is fastened to the backflow preventer 7 by the first fastening bolt 10 in a state where the flange portion 32 is fixed at the fixing position A. The first fastening bolt 10 is screwed into the bolt fastening portion 18a of the first pipe connecting flange 18 through the bolt fastening through hole 74 of the first pipe joint 6 from the first direction X1 side.

(Removal operation of backflow preventer to backflow preventer unit)
With reference to FIG. 1 and FIG. 4, the attachment / detachment operation | movement with respect to the backflow preventer unit 1 of the backflow preventer 7 is demonstrated. FIG. 4 is an explanatory view of the removing operation for removing the backflow preventer 7 from the backflow preventer unit 1 installed in the middle of the pipe. First, as shown in FIG. 1, the backflow preventer unit 1 is assumed to be installed between the primary side pipe 2 and the secondary side pipe 3 constituting the water supply mechanism. The flange portion 32 of the first pipe joint 6 is fixed at the fixed position A. The flange portion 32 is fastened to the first pipe connecting flange 18 of the backflow preventer 7 by the fastening bolt 10.

The backflow preventer 7 normally performs maintenance management by exchanging built-in components without being removed from the backflow preventer unit 1. However, when the casing of the backflow preventer 7 comes to be replaced or when the backflow preventer 7 breaks down, the backflow preventer 7 is removed from the backflow preventer unit 1 and a new backflow preventer 7 or the like. Replace with. When removing the backflow preventer 7, as shown in FIG. 4A, the lever 41 of the first ball stopcock 5 is operated to close the first ball stopcock 5 and the second ball stopwater. The second ball stop cock 9 is closed by operating the handle 51 of the stopper 9. And the 1st fastening bolt 10 which fastens the backflow preventer 7 and the 1st pipe joint 6
Remove. Thereafter, the retaining ring 33 is removed from the pipe portion 31 (the fixing tool mounting recess 65) of the first pipe joint 6.

  Here, the retaining ring 33 includes a knob 80 at each of the two open ends of the C-shaped portion 78. Therefore, the retaining ring 33 can be easily removed from the pipe portion 31 by using the knob portion 80 to widen the gap between the two open ends of the C-shaped portion 78.

  When the retaining ring 33 is removed from the tube portion 31, the flange portion 32 can move in the tube axis direction X in the first direction X1. Therefore, the flange portion 32 is moved from the fixed position A in the first direction X1. Thereby, the compressed state of the O-ring 24 compressed between the flange portion 32 and the first pipe connecting flange 18 is released. Further, since the flange portion 32 and the first pipe connecting flange 18 are separated from each other, the O-ring 24 is removed from the first annular groove 23 of the first pipe connecting flange 18.

  When the flange portion 32 is moved in the first direction X1 and the flange contact surface 32a is positioned on the first direction X1 side with respect to the end 31a of the pipe portion 31, the first pipe joint 6 and the backflow preventer 7 A gap H is formed between them. That is, since the gap G exists between the flange contact surface 32a and the end 31a of the tube portion 31 in the second direction X2 in a state where the flange portion 32 is fixed at the fixing position A of the tube portion 31, the flange contact surface 32a. Is positioned closer to the first direction X1 than the end 31a of the pipe part 31, a gap H having the same interval as the gap G is formed between the pipe part 31 and the backflow preventer 7.

  Next, the second fastening bolt 11 that fastens the backflow preventer 7 and the second pipe joint 8 is removed. Thereafter, the backflow preventer 7 is moved in the first direction X1 using the gap H (gap G). Thus, a gap I is provided between the second pipe connection flange 19 of the backflow preventer 7 and the flange portion 46 of the second pipe joint 8. Here, when the clearance I is provided, the compressed state of the O-ring 26 compressed between the second pipe connecting flange 19 and the flange portion 46 of the second pipe joint 8 is released.

  Thereafter, the backflow preventer 7 is moved in a direction orthogonal to the tube axis direction X, and the backflow preventer 7 is removed from the backflow preventer unit 1. Thereafter, the O-ring 24 is also removed from the backflow preventer unit 1.

  According to this example, when the retaining ring 33 is removed from the pipe portion 31 and the flange portion 32 at the fixed position A is moved in the first direction X1, a gap H is formed between the first pipe joint 6 and the backflow preventer 7. It is formed. Thereby, since the backflow preventer 7 can be moved in the tube axis direction X by the gap H (gap G), it is easy to remove the backflow preventer 7.

  When the flange portion 32 is moved in the first direction X1 and the backflow preventer 7 is moved in the first direction X1 using the gap H, the compressed state of the O-ring 26 is released. Accordingly, when the backflow preventer 7 is moved in the direction orthogonal to the tube axis direction X, the O-ring 24 does not act as a load between the backflow preventer 7 and the first pipe joint 6, and the backflow preventer 7 The O-ring 26 does not act as a load between the second pipe joint 8 and the second pipe joint 8. Further, when the backflow preventer 7 is moved in the direction orthogonal to the tube axis direction X, the O-ring 24 and the O-ring 26 are not damaged.

Next, when installing a new backflow preventer 7 between the first pipe joint 6 and the second pipe joint 8, the installation work can be performed by a procedure reverse to the above. That is, when a new backflow preventer 7 is installed between the first pipe joint 6 and the second pipe joint 8 together with the O-ring 24 and the O-ring 26, the retaining ring 33 extends from the pipe portion 31 of the first pipe joint 6. Is removed and the flange portion 32 is moved in the first direction X1, and the backflow preventer 7 is inserted between the first pipe joint 6 and the second pipe joint 8. Thereafter, the flange portion 32 is moved in the second direction X <b> 2 and fixed to the fixed position A by the retaining ring 33. Thereby, the flange 18 for 1st pipe connection of the backflow preventer 7 and the flange part 32 of the 1st pipe joint 6 are made to contact | abut. Further, the second pipe connection flange 19 of the backflow preventer 7 and the flange portion 46 of the second pipe joint 8 are brought into contact with each other. Then, the first pipe connection flange 18 of the backflow preventer 7 and the flange portion 32 of the first pipe joint 6 are fastened by the first fastening bolt 10. Further, the second pipe connecting flange 19 of the backflow preventer 7 and the flange portion 46 of the second pipe joint 8 are fastened by the second fastening bolt 11.

  Here, in the state where the flange portion 32 of the first pipe joint 6 is moved in the first direction X1, the total length of the first pipe joint 6 (as compared to the state where the flange portion 32 is fixed at the fixing position A). The length dimension in the tube axis direction X is shortened by the gap G. In other words, the gap between the first pipe joint 6 and the second pipe joint 8 is widened by the gap G with respect to the length dimension of the backflow preventer 7 in the pipe axis direction X. Therefore, it becomes easy to insert the backflow preventer 7 between the first pipe joint 6 and the second pipe joint 8 together with the O-ring 24 and the O-ring 26 having the compression allowance. Therefore, it is easy to install the backflow preventer 7 between the first pipe joint 6 and the second pipe joint 8.

(Modification)
In the above example, the O-rings 24 and 26 are held on the backflow preventer 7 side. However, the O-ring 24 may be held by the first pipe joint 6 and the O-ring 26 may be held by the second pipe joint 8. Good. That is, the first pipe joint 6 can include the O-ring 24, and the second pipe joint 8 can include the O-ring 26. In this case, the first flange end face 18 b of the first pipe connection flange 18 is a flat surface, and an annular groove is provided in the flange portion 32 of the first pipe joint 6 to mount the O-ring 24. Further, the second flange end face 19b of the second pipe connection flange 19 is a flat surface, the flange portion 46 of the second pipe joint 8 is provided with an annular groove, and the O-ring 26 is mounted.

  FIG. 5A is a side view of a first pipe joint 6A of a modified example in which an annular groove is provided in the flange portion 32 of the first pipe joint 6 and an O-ring 24 is attached, and FIG. It is a front view at the time of seeing 6A of 1 pipe joints from the 2nd direction X2. 5A is a cross-sectional view of the upper half of the first pipe joint 6A. Since the first pipe joint 6A of the modification has the same configuration as the first pipe joint 6 described above, the corresponding parts are denoted by the same reference numerals, and description thereof is omitted.

  The first pipe joint 6 </ b> A of this example includes an annular groove 81 that surrounds the pipe portion 31 on the flange contact surface 32 a of the flange portion 32. An O-ring 82 is detachably attached to the annular groove 81. Even if it does in this way, the effect similar to the case where an O-ring is hold | maintained at the backflow preventer 7 side can be acquired.

  In the above example, the pipe joint (first pipe joint 6) including the flange portion 32 that moves in the pipe axis direction X is disposed on the primary pipe 2 side of the backflow preventer 7. A pipe joint provided with a flange portion 32 that moves in the pipe axis direction X may be disposed on the secondary side pipe 3 side of 7. Further, pipe joints (first pipe joints 6) having flange portions 32 that move in the pipe axis direction X are arranged on both the primary pipe 2 side and the secondary pipe 3 side of the backflow preventer 7. Also good.

  Moreover, the outline shape at the time of seeing the annular plate part 72 of the flange part 32 from the pipe-axis direction X is not restricted to a square, For example, a circle may be sufficient.

Furthermore, it is good also as liquid-tight between the 1st pipe joint 6 and the backflow preventer 7, and between the 2nd pipe joint 8 and the backflow preventer 7 using packing instead of the O-rings 24 and 26. FIG. 6 is a front view of a backflow preventer unit 1A of a modified example in the case where the backflow preventer unit 1 includes a packing. FIG. 7 is an explanatory view of the first pipe joint 6 of the backflow preventer unit 1A of FIG. 6 and 7, the first pipe joint 6 is a cross-sectional view of the upper part of the pipe axis L. Further, in FIG. 6, the second pipe joint 8 is a cross-sectional view of the upper part of the pipe axis L. In FIG. 6 and FIG. 7, the flange portion 32 of the first pipe joint 6 is fixed at a fixed position A by a retaining ring 33. Since the backflow preventer unit 1A of the present example has a configuration corresponding to that of the backflow preventer unit 1, the corresponding portions are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 6, in the backflow preventer unit 1 </ b> A, the first pipe joint 6 includes a packing 91. Further, the second pipe joint 8 includes a packing 92. More specifically, as shown in FIG. 7, the first pipe joint 6 of the backflow preventer unit 1 </ b> A has an annular projecting portion projecting in the second direction X <b> 2 at the inner peripheral edge portion of the annular plate portion 72 of the flange portion 32. 93. The front end surface of the annular projecting portion 93 (the annular end surface of the annular projecting portion 93 in the second direction X2) is a plane orthogonal to the pipe axis L, and can be in contact with the first pipe connecting flange 18. It is the surface 32a.

  The packing 91 is made of an elastic member such as rubber. Further, the packing 91 is annular and has a flat shape with a thin tube axis direction X. The packing 91 is held by the flange portion 32 in a state where the annular protrusion 93 is inserted into the center hole. The thickness dimension of the packing 91 in the tube axis direction X is longer than the projecting dimension of the annular protrusion 93 in the tube axis direction X. Further, the thickness dimension of the packing 91 in the tube axis direction X is such that the flange portion 32 of the first pipe joint 6 is fixed at the fixing position A at the tip end (flange contact surface 32a) of the annular protrusion 93. It is 1/2 or less of the gap G with the end (opening edge of the pipe part 31) 31a of the pipe part 31 in the second direction X2. In addition, the 1st flange end surface 18b of the backflow preventer 7 is a plane. That is, in the backflow preventer unit 1A of this example, the first groove end surface 18b of the backflow preventer 7 is not provided with the annular groove 23 for holding the O-ring.

  Moreover, the 2nd pipe joint 8 of the backflow preventer unit 1A is provided with the annular | circular shaped protrusion 95 which protrudes in the 1st direction X1 in the inner peripheral part of the flange part 46, as shown in FIG. The front end surface of the annular projection 95 (the annular end surface of the annular projection 95 in the first direction X1) is a plane orthogonal to the tube axis L, and is an end surface 46b that can come into contact with the second pipe connection flange 19. is there. The packing 92 is made of an elastic member such as rubber. The packing 92 has an annular shape and has a flat shape with a thin tube axis direction X. The packing 92 is held by the flange portion 46 in a state where the annular protrusion 95 is inserted into the center hole. Here, the thickness dimension of the packing 92 in the tube axis direction X is longer than the projecting dimension of the annular projection 95 in the tube axis direction X. Further, the thickness dimension of the packing 91 in the tube axis direction X is ½ or less of the gap G. In addition, the 2nd flange end surface 19b of the backflow preventer 7 is a plane. That is, in this example, the annular groove 25 for holding the O-ring is not provided on the second flange end surface 19b of the backflow preventer 7.

  As shown in FIG. 6, the flange portion 32 of the first pipe joint 6 and the first pipe connection flange 18 of the backflow preventer 7 are fastened, and the flange portion 46 of the second pipe joint 8 and the first backflow preventer 7 In a state where the two pipe connection flanges 19 are fastened, the packing 91 is elastically deformed between the first pipe joint 6 and the backflow preventer 7 to prevent backflow prevention with the flange contact surface 32a of the first pipe joint 6. The first flange end surface 18b of the container 7 comes into contact. As a result, the packing 91 is interposed between the first pipe joint 6 and the backflow preventer 7 so that the space between the first pipe joint 6 and the backflow preventer 7 is liquid-tight. Further, the packing 92 is elastically deformed between the second pipe joint 8 and the backflow preventer 7 so that the end face 46 b of the second pipe joint 8 and the second flange end face 19 b of the backflow preventer 7 come into contact with each other. As a result, the packing 92 is interposed between the second pipe joint 8 and the backflow preventer 7 so that the space between the first pipe joint 8 and the backflow preventer 7 is liquid-tight.

Also in this example, when the retaining ring 33 is removed from the pipe part 31 of the first pipe joint 6 and the flange part 32 at the fixed position A is moved in the first direction X1, the first pipe joint 6 and the backflow preventer 7 A gap corresponding to the gap G is formed between them. Therefore, using this gap, the compressed state of the packing 91 can be released and the packing 91 can be removed from the backflow preventer unit 1A. Moreover, since the backflow preventer 7 can be moved in the tube axis direction X using the formed gap, it is easy to remove the backflow preventer 7.

  Further, in the state where the flange portion 32 of the first pipe joint 6 is moved in the first direction X1, the total length (pipe of the first pipe joint 6 is compared with the state where the flange portion 32 is fixed at the fixing position A. (Length dimension in the axial direction X) is shortened by the gap G. In other words, the gap between the first pipe joint 6 and the second pipe joint 8 is widened by the gap G with respect to the length dimension of the backflow preventer 7 in the pipe axis direction X. Therefore, it becomes easy to interpose the backflow preventer 7 between the first pipe joint 6 having the packing 91 having the compression allowance and the second pipe joint 8 having the packing 92 having the compression allowance. Therefore, it is easy to install the backflow preventer 7 between the first pipe joint 6 and the second pipe joint 8.

  In addition, the pipe joint (first pipe joint 6) including the flange portion 32 moving in the pipe axis direction X is not limited to the backflow preventer 7, and a device such as a valve having a pipe connection flange is connected to the pipe. Can be used. Here, as a device having a pipe connection flange, there is a valve including a gate valve, a globe valve, a butterfly valve, and the like. Examples of equipment having a flange for pipe connection include a strainer, a flow meter, and a water meter.

  In the above example, the retaining ring (fixing tool) 33 includes the C-shaped portion 78, the bent portion 79, and the knob portion 80, but the retaining ring is a C-ring including only the C-shaped portion 78. May be.

1 ・ 1A ・ ・ Backflow preventer unit 5 ・ ・ ・ 1st ball stopcock (stopcock)
6 ... 1st pipe joint (pipe joint)
7 ... Backflow preventer (equipment)
10 ... 1st fastening bolt (fastener)
12.13.14 ... Valve 17 ... Valve 18 ... First pipe connection flange (Pipe connection flange)
18b ... 1st flange end surface 19 ... 2nd pipe connection flange 19b ... 2nd flange end surface 21 ... Fluid inlet 22 ... Fluid outlet 24 ... O-ring 31 ... Pipe 32 ... Flange 32a ... Flange contact surface 32 ... Flange 32a ... Flange contact surface 33 ... Retaining ring (fixing tool)
34... Connection portion 64... Projection 65...
66 ... O-ring mounting groove (annular groove)
67 ... O-ring (second O-ring)
75 ... Notch recess 75a ... Inner wall surface 78 ... C-shaped part 79 ... Bent part 80 ... Knob part 81 ... Annular groove 82 ... O-ring (second O ring)
91 ... packing 93 ... annular projection (annular projection)
A ... fixed position G ... gap X ... tube axis direction X1 ... first direction X2 ... second direction

Claims (10)

In the pipe joint that is arranged between the pipe having the flange for pipe connection and the pipe and connects the equipment and the pipe,
A pipe section;
An annular flange portion located on the outer peripheral side of the tube portion in a state movable in the tube axis direction of the tube portion;
A fixing tool that is detachably attached to the pipe part and fixes the flange part to a predetermined fixing position in the pipe part,
The pipe portion includes a connection portion that connects the pipe to an end portion in the first direction of the pipe axis direction,
The flange portion is a flange contact surface in which an end surface in a second direction opposite to the first direction can contact the flange for pipe connection,
In the state in which the flange portion is fixed at the fixed position, the flange contact surface is positioned in front of an end of the pipe portion in the second direction. In claim 1,
The tube portion has a protrusion protruding to the outer peripheral side, and a fixture mounting portion provided at a position spaced apart in the first direction of the protrusion,
The flange portion includes a notch recess extending in the first direction from the flange contact surface on an inner peripheral surface thereof,
In a state where the fixing device is mounted on the fixing device mounting portion and the flange portion is fixed at the fixing position, the protrusion is inserted into the notch recess, and the inside of the notch recess in the first direction. A pipe joint that abuts against a wall surface and that the fixture abuts against the flange portion from the side in the first direction. In claim 2,
Having an O-ring,
The tube portion includes an annular groove between the protrusion and the fixture mounting portion,
The O-ring is attached to the annular groove, and is interposed between the flange portion and the pipe portion arranged at the fixed position. In claim 2,
The fitting is a metal retaining ring having a C-shaped portion. In any one of claims 1 to 4,
Having an annular packing,
The flange portion includes an annular projecting portion that surrounds the tube portion and projects in the second direction,
The front end surface of the annular protrusion is the flange contact surface,
The packing is characterized in that the packing is held by the flange portion in a state where the annular projecting portion is inserted into a center hole thereof. In any one of claims 1 to 4,
Having a second O-ring,
An annular groove surrounding the pipe portion is formed on the flange contact surface,
The pipe joint, wherein the second O-ring is mounted in the annular groove. A pipe joint according to any one of claims 1 to 4,
A backflow preventer,
A fastener for fastening the pipe joint and the backflow preventer,
The backflow preventer includes a valve chamber that accommodates a valve body, first and second pipe connection flanges provided on both sides of the valve chamber, and the first pipe connection flange. A fluid inflow port that opens at the end face of the first flange located on the opposite side of the valve chamber and communicates with the valve chamber, and a second location of the second pipe connection flange located on the opposite side of the valve chamber. A fluid outlet opening at the end face of the flange and communicating with the valve chamber,
The first flange end surface and the second flange end surface are parallel,
The fastener includes the pipe joint and the backflow preventer in a state where the flange contact surface of the flange portion fixed at the fixed position is in contact with the first flange end surface or the second flange end surface. A backflow preventer unit characterized in that it is detachably fastened. In claim 7,
The pipe joint includes an annular packing,
The flange portion includes an annular projecting portion that surrounds the tube portion and projects in the second direction,
The front end surface of the annular protrusion is the flange contact surface,
The packing is held by the flange portion in a state where the annular protrusion is inserted into the center hole thereof,
When the pipe joint and the backflow preventer are fastened by the fastener, the packing is elastically deformed between the flange portion and the backflow preventer, and between the pipe joint and the backflow preventer. A backflow preventer unit characterized by being liquid-tight. In claim 7,
Comprising a second O-ring interposed between the pipe joint and the backflow preventer to make the space between the pipe joint and the backflow preventer liquid-tight;
The first flange end surface includes a first annular groove surrounding the fluid inlet,
The second flange end surface includes a second annular groove surrounding the fluid outlet;
The backflow preventer unit, wherein the second O-ring is attached to the first annular groove or the second annular groove. In any one of claims 7 to 9,
A water stopcock for connecting the pipe joint and the pipe between the pipe joint and the pipe;
The said water stop cock is connected to the connection part of the pipe part of the said pipe joint, The backflow preventer unit characterized by the above-mentioned.

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