Hydraulic Testing Equipment for Pipe Joints

Abstract

To provide a water pressure testing device for a pipe joint that can increase the diameter of a water stopping member smoothly while preventing the water stopping member from hanging down.SOLUTION: The water pressure testing device for a pipe joint includes: a body part 2; a plurality of pressing plates 4 arranged in a circle along the inner surface of the joint part of a connected pipe body 3 and supported movably in a radial direction of the pipe body 3 by the body part 2; a water dropping member 5 made of a circular elastic body hanging on the outer side of the pressing plate 4 and pressed against the inner surface in association with movement of the pressing plate 4 to the outside in a radial direction; and a drawing member 6 for drawing the water stopping member 5 close to the center of the pipe axis.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a hydraulic testing device for pipe joints. [Background technology]

[0002] In pipelines for water supply, sewerage, industrial water, etc. constructed with ductile iron pipes, etc., after the work to connect the pipes is completed, a test is carried out to apply water pressure to the joints in order to check their soundness (watertightness). For small-diameter pipes, the method of applying water pressure is to directly fill the pipeline with water, while for large-diameter pipes with a nominal diameter of 900 or more (also sometimes 800 or 700), the most common method is for a worker to enter the pipeline, press a ring-shaped waterstop against the inner surface of the joint, and fill the gap between the waterstop and the inner surface of the joint with pressurized water (for example, 0.5 MPa).

[0003] For example, in the water pressure testing device disclosed in Patent Document 1, first, a sealant 5 (waterstop member) with a U-shaped circumferential cross section is placed on the inner surface of the pipe joint 1, and a waterstop plate 8 is applied to the inner surface. Next, the waterstop plate 8 is pressed outward by reaction plates 20, 21 which are advanced outward in the pipe radial direction by operating a set screw 22, and this pressing force brings the tongue-shaped portion 7 of the sealant 5 into close contact with the inner surfaces of the socket 2 and the insertion port 3, forming an annular sealed space 33 in the pipe joint 1 for filling with water under pressure (see Figs. 1, 7(b) and the like in Patent Document 1).

[0004] Also, as shown in Fig. 9, a water pressure testing device has been proposed in which rubber ring holding members 52 that hold rubber rings 51 as water-stopping members are fixed to the outer periphery of a pressing plate 50 by welding or the like, and the rubber rings 51 are then hung in advance on each of the rubber ring holding members 52, so that the rubber rings 51 can be brought into contact with the inner surface of the joint more easily. The rubber ring holding members 52 are members with a U-shaped cross section in the circumferential direction, and their circumferential ends overlap with the adjacent rubber ring holding members 52 so as to be able to slide freely. The rubber rings 51 and the rubber ring holding members 52 are also able to slide relative to each other in the circumferential direction.

[0005] When a bolt 54 provided on a main body 53 in the joint is screwed in, the rubber ring holder 52 is pushed outward in the radial direction together with the pressing plate 50. Then, the rubber ring 51 hung on the rubber ring holder 52 is pressed against the inner surface of the joint, forming an annular sealed space for filling with water under pressure. This main body 53 is provided with wheels (see the wheels 12 shown in FIG. 1 and other figures showing an embodiment of the present application), and tests can be performed at each joint while moving it along the pipe axis.

[0006] 9, a rubber ring 51 having an outer diameter about 20 to 40 mm smaller than the inner diameter of the joint is often used so that a gap of about 10 to 20 mm is secured around the entire circumference between the inner surface of the joint and the rubber ring 51. In this way, the hydraulic test device can be freely moved along the pipe axis while preventing contact between the inner surface of the joint and the rubber ring 51. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 63-240 Summary of the Invention [Problem to be solved by the invention]

[0008] In the configuration shown in FIG. 9, the rubber ring 51 needs to be expanded by the gap between the inner surface of the joint and the rubber ring 51 by screwing in the bolt 54. This expansion resists the elasticity of the rubber ring 51, so the bolt 54 needs to be screwed in with a considerable force, and the screwing work also requires time. In order to reduce this screwing work, the gap between the inner surface of the joint and the rubber ring 51 is reduced, that is, a rubber ring 51 with a large outer diameter is used, thereby reducing the screwing force of the bolt 54 when expanding the rubber ring 51 and shortening the screwing work time. However, by increasing the outer diameter of the rubber ring 51, the rubber ring 51 sags due to its own weight, and there is a problem that the rubber ring 51 rubs against the inner bottom surface B of the pipe when the hydraulic test device is moved in the pipe axial direction (see the rubber ring 51 shown by the dashed line in FIG. 9).

[0009] Therefore, an object of the present invention is to enable the diameter of a water-stopping member to be smoothly expanded while preventing the water-stopping member from sagging. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides: A main body portion, a plurality of presser plates disposed annularly along the inner surface of the joint portion of the connected pipes and supported by the main body so as to be movable in the radial direction of the pipes; a water-stopping member made of an annular elastic body that is hung around the outer periphery of the pressing plate and pressed against the inner surface as the pressing plate moves radially outward; A retracting member that retracts the water-stopping member toward the center of the pipe axis; A water pressure testing device for a pipe joint having the above structure was constructed.

[0011] In this way, by using the retracting member to retract the waterstop member toward the center of the pipe axis, it is possible to prevent the waterstop member from sagging under its own weight, and to prevent the waterstop member from rubbing against the bottom surface of the pipe when the hydraulic test device is moved along the pipe axis. Moreover, since the circumferential length of the waterstop member can be increased, it is possible to reduce the screwing force of the bolt when expanding the diameter of the waterstop member, and also to shorten the screwing work time.

[0012] In the above-mentioned configuration, it is preferable that the pull-in member is provided on the lower end side of the water-stopping member.

[0013] In this way, sagging at the lower end of the water-stopping member can be reliably prevented.

[0014] In each of the above configurations, it is preferable that the device further includes wheels that enable the main body to move along the axial direction of the pipe body.

[0015] In this way, the water pressure testing device can be freely moved along the pipe axial direction, so that watertight tests of each joint can be carried out smoothly.

[0016] In each of the above configurations, it is preferable that some of the multiple pressure plates move radially inward more than the other pressure plates, and that the retraction member can retract the water-stopping member suspended across some of the pressure plates toward the inner diameter side of the arc formed by the other pressure plates.

[0017] In this way, the bridge path of the water-stopping member becomes longer, so that the water-stopping member having a long circumferential length can be reliably prevented from becoming loose. Effect of the Invention

[0018] In this invention, the water-stopping member is pulled toward the center of the pipe axis by the pulling member, which prevents the water-stopping member from sagging under its own weight and causing friction between the bottom surface of the pipe and the water-stopping member, and also reduces the screwing force of the bolt when expanding the water-stopping member, thereby shortening the screwing work time. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a cross-sectional view showing an embodiment of a hydraulic pressure test device for a pipe joint according to the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the operation of the hydraulic test device for the pipe joint shown in FIG. [Diagram 3] Cross-sectional view taken along line III-III in Figure 1. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 2 [Diagram 5] 1 shows a first member in which a pressing plate and a rubber ring holding member are integrated, (a) being a front view, (b) being a side view of (a), and (c) being a view taken in the direction of the arrow A of (a). [Figure 6] 1 shows a second member in which a pressing plate and a rubber ring holding member are integrated, where (a) is a front view, (b) is a side view of (a), and (c) is a view taken in the direction of the arrow A of (a). [Figure 7] FIG. 4 is a cross-sectional view showing a first modified example of FIG. 3; [Figure 8] FIG. 4 is a cross-sectional view showing a second modified example of FIG. 3; [Figure 9] FIG. 1 is a cross-sectional view showing a main part of a hydraulic testing device according to a conventional technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An embodiment of a hydraulic testing device 1 for a pipe joint according to the present invention (hereinafter, abbreviated as hydraulic testing device 1) will be described with reference to Figs. 1 to 6.

[0021] This water pressure testing device 1 has as its main components a main body 2, a plurality of pressure plates 4 arranged in a ring shape along the inner surface of the joint part of the connected pipe bodies 3 (receiving side pipe body 3a and inserting side pipe body 3b) and supported by the main body 2 so as to be movable in the radial direction of the pipe bodies 3, a rubber ring (hereinafter given the same symbol as the water stop member 5) as a water stop member 5 made of a ring-shaped elastic body that is stretched across the outer periphery of the pressure plates 4 and pressed against the inner surface of the joint part as the pressure plates 4 move radially outward, and a coil spring (hereinafter given the same symbol as the retraction member 6) as a retraction member that retracts the rubber ring 5 toward the center of the pipe axis.

[0022] As shown in Fig. 3 etc., the main body 2 is a steel annular member with six through holes formed along its circumferential direction. A nut 8 is fixed in each through hole for screwing a bolt 7 from its inner peripheral surface side. A guide hole (not shown) is formed near each nut 8 into which a guide rod 9 provided on the pressing plate 4, which will be described in detail later, is inserted. Hook holes (not shown) for engaging the hooks of the coil spring 6 are formed at the left and right ends and the bottom end of the outer periphery of the main body 2.

[0023] A base 10 is connected to the bottom of the main body 2, and wheels 12 equipped with brakes 11 are provided on the base 10. The wheels 12 allow the hydraulic test device 1 to be freely moved to any position along the pipe axis, and the brakes 11 can be operated at the joint position to stop the hydraulic test device 1 reliably at that position for testing.

[0024] As shown in Fig. 5 and Fig. 6, the pressing plate 4 is a steel member having a plate-shaped base 13 that is curved in the circumferential direction while keeping a predetermined gap with the main body 2 and has flanges that rise outward in the radial direction at both ends in the pipe axial direction, a substantially X-shaped rib 14 provided on the inner peripheral surface of the base 13 to reinforce the base 13, a bolt holding portion 15 provided on the inner peripheral surface of the base 13 to hold the screw tip of the bolt 7 so that it can rotate relatively and cannot move relatively in the axial direction, and a guide rod 9 that rises inward from the inner peripheral surface of the base 13. In this embodiment, six pressing plates 4 are arranged in a ring shape around the entire circumference of the main body 2. Note that in Fig. 3, Fig. 4, Fig. 5(a) and Fig. 6(a), illustration of some of the ribs 14 near the bolt holding portion 15 is omitted.

[0025] A rubber ring holding member 16 for holding the rubber ring 5 is provided on the outer peripheral surface of the base 13 of the pressing plate 4. The rubber ring holding member 16 is a member having a U-shaped circumferential cross section, with standing portions provided radially outward on both ends in the axial direction of the pipe to prevent the rubber ring 5 from shifting in the axial direction. The pressing plate 4 and the rubber ring holding member 16 are integrated together by a fixing means such as welding or adhesive.

[0026] In this embodiment, two types of members (first member 17a, second member 17b) are used, which have different shapes of the pressing plate 4 and the rubber ring holding member 16 in different ways of integration. As shown in Figs. 5(a), (b), and (c), the first member 17a is configured such that one circumferential end of the rubber ring holding member 16 provided on the pressing plate 4 protrudes toward the one circumferential end side from the pressing plate 4. A semicircular cutout is formed on one circumferential end side of the first member 17a for passing an air vent pipe 18 or a water filling pipe 19, which will be described later. As shown in Figs. 6(a), (b), and (c), the second member 17b is configured such that the circumferential length of the rubber ring holding member 16 is shorter than the pressing plate 4 at both circumferential ends, and the outer circumferential surfaces of both circumferential ends of the pressing plate 4 are exposed.

[0027] 3 and other figures, the various components are arranged in the following order from the tube top side to the tube bottom side of the main body 2: first component 17a (tube top side), second component 17b, and first component 17a (tube bottom side). At this time, the protruding ends of the rubber ring holder 16 of the first component 17a on the tube top side and tube bottom side cover the exposed parts of the outer circumferential surface of the pressing plate 4 of the second component 17b from both directions, so that the components 17a, 17b are continuous with no gaps in the circumferential direction.

[0028] The rubber ring 5 is an annular rubber member with a U-shaped circumferential cross section that has no breaks in the circumferential direction. The rubber ring 5 is hung over the outer circumferential surface of a rubber ring holding member 16 (first member 17a, second member 17b) that is integrated with the pressing plate 4. As shown in FIG. 1 etc., a pair of annular seal parts 20 are formed at both ends in the tube axial direction of the rubber ring 5, and a space that is open radially outward is formed between the two seal parts 20. An air vent pipe 18 that communicates with the space is provided at the tube top of the rubber ring 5, and a water filling pipe 19 that communicates with the space is provided at the tube bottom. Two hook holes (not shown) are formed at the bottom and both sides of the seal parts 20 of the rubber ring 5 at positions that do not affect the watertightness.

[0029] Protective covers 21 are provided on the tube top side and tube bottom side of the rubber ring 5. The protective cover 21 is a plate-like member that is curved in the circumferential direction and has flanges that rise outward in the radial direction at both ends in the tube axial direction. A through hole (not shown) is formed in the protective cover 21 for inserting the air vent pipe 18 or the water filling pipe 19. When the air vent pipe 18 and the water filling pipe 19, each having a threaded portion, are inserted into the through hole and a nut (not shown) is tightened, the protective cover 21 is fixed to the rubber ring 5. By fixing the protective cover 21 to the rubber ring 5, the vertical position of the rubber ring 5 is determined, and damage caused by the rubber ring 5 being shifted in the circumferential direction can be prevented.

[0030] The coil spring 6 has hooks formed on both ends, one hook being engaged with a hook hole formed in the main body 2, and the other hook being engaged with a hook hole formed in the rubber ring 5. A coil spring 6 having the minimum spring constant required for retracting the rubber ring 5 is selected so as to prevent excessive load when the rubber ring 5 is expanded by screwing in a bolt 7, which will be described later.

[0031] When moving the hydraulic test device 1 within the pipe, as shown in Figures 1 and 3, the two upper and lower bolts 7 are loosened to move the first member 17a to a predetermined position, and the two left and right bolts 7 are loosened further than the two upper and lower bolts 7 to move the second member 17b further toward the inner diameter side from the predetermined position of the first member 17a.

[0032] At this time, the left and right sides of the rubber ring 5 are pulled toward the center of the pipe axis to lengthen the bridge path of the rubber ring 5, preventing the rubber ring 5, which has a long circumference, from loosening. At the same time, the lower part of the rubber ring 5 is pulled toward the center of the pipe axis by the coil spring 6, ensuring a gap (e.g., 10 to 20 mm) between the rubber ring 5 and the inner wall of the pipe that does not interfere with the movement of the hydraulic test device 1. This ensures that the rubber ring 5 is prevented from sagging under its own weight and rubbing against the bottom surface of the pipe. Moreover, since the circumference of the rubber ring 5 can be lengthened, the screwing force of the bolt 7 when expanding the diameter of the rubber ring 5 can be reduced and the screwing work time can be shortened.

[0033] In this embodiment, a coil spring 6 is used as the retracting member 6 for retracting the rubber ring 5, but other members such as elastic rubber or a cylinder (jack) can be widely used as long as they have the function of retracting the rubber ring 5.

[0034] When the hydraulic test device 1 reaches the joint where the watertightness test is to be performed, the first member 17a and the second member 17b are moved radially outward by alternately tightening the two bolts 7 on the top and bottom and the two bolts 7 on the left and right in a balanced manner, as shown in Figures 2 and 4. At this time, the rubber ring 5 stretched across the first member 17a and the second member 17b expands in diameter and is pressed against the inner surface of the joint, forming an airtight space between the rubber ring 5 and the inner surface of the joint.

[0035] By injecting water into the sealed space through the water filling pipe 19 (see arrow w in FIG. 4) while venting air from the sealed space through the air vent pipe 18 (see arrow a in FIG. 4), the sealed space can be filled with water pressurized to a specified pressure (e.g., 0.5 MPa). After pressurization to the specified pressure, the pressure is maintained for a specified time (e.g., 5 minutes), and the watertightness is judged based on whether the specified test water pressure (e.g., 0.4 MPa or higher) can be maintained.

[0036] When the first member 17a and the second member 17b are displaced radially outward as the bolt 7 is screwed in, the gap between the adjacent presser plates 4 widens, but because the rubber ring holder 16 fixed to one of the adjacent presser plates 4 is arranged to cover the other adjacent presser plate 4, at least one of the presser plate 4 or the rubber ring holder 16 is always present on the inner diameter side of the rubber ring 5. Therefore, the rubber ring 5 is stably supported from its inner diameter side over the entire circumferential direction, and this rubber ring 5 can be reliably pressed against the inner surface of the joint portion.

[0037] In the above, a configuration in which the coil spring 6 is provided on the bottom and the left and right sides of the rubber ring 5 has been described, but as shown in Fig. 7, a configuration in which the coil spring 6 is provided only on the bottom of the rubber ring 5 and the left and right coil springs 6 are omitted, or as shown in Fig. 8, a configuration in which the coil spring 6 is provided only on the left and right sides of the rubber ring 5 and the lower coil spring 6 is omitted, can also be used. In these configurations, as in the above, it is possible to prevent the rubber ring 5 from sagging under its own weight and causing friction between the rubber ring 5 and the bottom surface of the pipe, and it is possible to reduce the screwing force of the bolt 7 when expanding the diameter of the rubber ring 5, thereby shortening the screwing work time.

[0038] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. Therefore, the scope of the present invention is defined by the claims, not by the above description, and is intended to include the meaning equivalent to the claims and all modifications. [Explanation of symbols]

[0039] 1. Hydraulic pressure testing equipment for pipe joints 2 Main unit 3. Body 3a Receiving tube 3b Insertion tube 4 Retaining plate 5. Water-stopping material (rubber ring) 6 Retraction member (coil spring) 7 Volts 8 Nuts 9 Guide rod 10 Base 11. Brakes 12 wheels 13 Base 14 Ribs 15 Bolt holder 16 Rubber ring retaining member 17a First member 17b Second member 18 Air vent pipe 19 Water filling pipe 20 Seal part 21 Protective cover

Claims

1. A main body portion (2); a plurality of pressing plates (4) arranged in an annular shape along the inner surface of the joint portion of the connected pipe body (3) and supported by the main body portion (2) so as to be movable in the radial direction of the pipe body (3); a water-stopping member (5) made of an annular elastic body that is hung across the outer periphery of the pressing plate (4) and pressed against the inner surface as the pressing plate (4) moves radially outward; A retracting member (6) that retracts the water-stopping member (5) toward the center of the pipe axis; wherein the pull-in member (6) is directly connected to the water-stopping member (5).

2. 2. The water pressure testing device for a pipe joint according to claim 1, wherein the pull-in member (6) is provided below the water-stopping member (5) where sagging occurs due to its own weight.

3. 3. The hydraulic testing device for a pipe joint according to claim 1, further comprising wheels (12) for enabling the main body (2) to move along the axial direction of the pipe body (3).

4. 4. A water pressure testing device for a pipe fitting as claimed in any one of claims 1 to 3, wherein some of the multiple pressure plates (4) can move radially inward relative to the other pressure plates (4), and the water-stopping member (5) suspended across some of the pressure plates (4) can be pulled inwardly by the retraction member (6) relative to the arc formed by the other pressure plates (4).

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