JP2009036250A - Back-flow preventive water cutoff valve and check valve unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein disassembling and re-assembling of a valve box constituting a tap body requires much time and labor because it was impossible to check back-flow preventive performance of a check valve in a back-flow preventive water cutoff valve without stopping water supply and the valve box has to be disassembled when exchanging the check valve and cleaning a strainer. <P>SOLUTION: A bypass flow passage 4 communicating from a valve chamber of a main valve to a secondary side rear part of the check valve is set. A strainer installing element 3 capable of switching a water passage passing through the check valve and the bypass flow passage, and detachably installing a filter screen at a tip end on a primary side of the check valve is formed. Therefore, a unit which can be inserted in and pulled out from a water cutoff valve body is constituted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention can check the backflow prevention performance of the built-in check valve without stopping the water supply system, and can set and replace the check valve cartridge, strainer unit, etc. with a structure that allows the stop cock to be disassembled. The present invention relates to a check valve and a check valve unit incorporated therein.

  Conventionally, the check valve has a check valve on the secondary side of the shutoff plug body, and the check valve must be removed for water pressure testing and drainage. For the check, set a check plug that leads to the water channel between the primary shut-off plug and the check valve, and leak water from the check plug when the primary shut-off plug is closed and the check plug is removed. Depending on the presence or absence of this, a shutoff plug body is also set on the secondary side, a water column pipe is erected between the check valve and the secondary shutoff plug body, and both shutoff plug bodies are closed and water pressure is passed through the water column pipe. The method of confirming the presence or absence of water leakage from the check plug when the check plug is removed has been performed.

  Thereafter, when water pressure is applied from the secondary side for water pressure testing or drainage, for example, as shown in Patent Documents 1 and 2, do not operate the check valve set on the secondary side of the shutoff plug body. A bypass channel connecting the primary side and the secondary side of the check valve was provided, and pressurization from the secondary side of the check valve became possible by opening and closing the bypass channel.

  However, in the configurations of Patent Documents 1 and 2, the check valve can be used without stopping the water supply from the primary side of the cutoff main plug body even if the check valve can be removed without removing the check valve at the time of water pressure test or draining. It is currently impossible to check the backflow prevention performance.

In addition, as a strainer for removing dust from the water passage from the primary side to the secondary side, a bag shape as shown in Patent Document 3 or a cylindrical shape as shown in Patent Document 4 is used. However, both have been fixedly set in the valve box as independent members.
JP 2000-329256 A JP 2007-009506 A Japanese Patent No. 3327843 Japanese Patent Laid-Open No. 11-148571

  However, the check for the check valve performance of the check valve, which must be maintained at all times, is based on the premise that the check valve primary side closing plug is closed as described above. Since the water supply has to be stopped, there has been a problem that causes great inconvenience to the consumer every time the backflow prevention performance is checked.

  In addition, since the check valve and strainer are fixedly incorporated in the valve box as independent members, the valve box must be disassembled when replacing the check valve and cleaning the strainer. It took a lot of time and effort to disassemble and reassemble the valve box.

  Furthermore, the strainer that removes dust from the water passage from the primary side to the secondary side employs a method of fitting in the water passage, and the dust that is filtered when the screen faces the water flow is filtered. Since the trap is concentrated in the central portion, the trapped dust prevents water from passing through and requires frequent cleaning.

  The present invention is intended to address the above-described problems. When the ball valve, which is a shutoff plug body, is rotated by a predetermined angle, the secondary water channel is closed and the primary water channel is in a semi-open state. The primary side opening diameter of the valve water passage hole is made larger and the secondary side opening diameter is made smaller, and the water passage secondary side opening part that is off the secondary side water passage by the rotation of the ball valve by a predetermined angle is connected and reversed. A bypass channel communicating with the secondary side rear side of the stop valve was set, and a check plug was set between the ball valve and the check valve.

  With this configuration, water supply on the check valve primary side is stopped, but water supply to the consumer is performed by a bypass flow path communicating with the rear side of the check valve on the secondary side, which causes the worst situation such as water breakage. It is possible to apply a back pressure to the wearing check valve, remove the check plug, and check the backflow prevention performance only by operating the main plug.

  Further, the rear part of the secondary side of the valve box main body that houses the ball valve is configured as an fitting frame that detachably accommodates the check valve unit, and a secondary pipe is joined to the fitting frame. The pipe is detachably connected to cover the fitting frame, and the check valve unit can be cleaned or replaced without removing the valve box body simply by removing the telescopic pipe.

  Next, a checker valve set on the secondary side of the main plug ball valve is replaced with a cylindrical strainer provided with a fitting mechanism and an O-ring fitting part on the inner periphery of the water channel on the primary side of the check valve cartridge. Form a mounting body, attach a strainer screen to the tip of the strainer mounting body in a detachable manner to form a check valve unit, and remove the telescopic tube to pull out the check valve unit from the fitting frame. Valve replacement and strainer cleaning can be performed at once.

  Furthermore, the strainer screen is attached to the strainer-attached body by a retaining ring that is fitted with the strainer screen and the tip of the strainer-attached body sandwiched from both sides, and the strainer screen is attached to and detached from the attached body independently. Only the strainer screen can be replaced, and the central portion of the strainer screen is bulged to the primary side.

  With this configuration, the strainer screen that has been exchanged and discarded together with the frame can be replaced as a single screen, making it possible to employ a variety of screens in terms of materials and mesh, and a significant increase in material. Added savings.

  Further, by causing the central portion of the strainer screen to bulge to the primary side, the dust to be filtered collides with the central bulge portion of the screen and is swept away by the peripheral area of the bulge by water pressure and concentrated on the central portion of the screen. It is possible to reduce the number of times the strainer is cleaned.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a stopper main body of a water stop valve, which is provided with a ball valve 2 having a water passage hole 21 in which a primary side opening 21a has a large opening diameter and a secondary side opening 21b has a small opening diameter. In the water state, the opening 21a of the water passage hole 21 is joined to the primary side water supply path 11, and 21b is joined to the water supply path 12 of the fitting frame 13 that accommodates the check valve unit 3 in a removable manner. It is in the state connected with the outflow port 23 of the chamber 22a as a flow path.

  When the ball valve 2 is rotated approximately 45 degrees by the turning operation of the operation handle 25 provided at the upper part of the stopper body 1, the secondary side opening 21b having a small opening diameter is detached from the water supply channel 12 and the ball valve chamber. 22b and the water channel to the check valve chamber 22a is closed, but the primary side opening 21a having a large opening diameter is in a semi-open state, and the water supply from the primary side water supply channel 11 is continued and the ball is It flows into the bypass channel 4 through the valve chamber 22b.

  When the ball valve 2 is rotated 90 degrees, the opening 21a of the water passage hole 21 is removed from the primary water supply passage 11 and is closed by the side abdomen of the ball valve body 2 to stop water supply. In this state, the check valve unit 3 fitted in the fitting frame 13 can be easily removed by removing the cap nut 42 that is screwed into the fitting frame 13 and fastened to the expansion tube 41. Cleaning and replacement can be performed.

  The check valve unit 3 is formed with a cylindrical strainer mounting body 32 on the primary side of the check valve cartridge 31, and a male screw 13 a screwed on the outer periphery of the checker unit 3. A screw 13b and an O-ring fitting portion 13c are provided, and a strainer screen 32a is detachably attached to a distal end of the strainer attachment body 32 by a retaining ring 33.

  The retaining ring 33 is formed by dividing a ring formed of synthetic resin into two parts, and an engagement protrusion 33a that fits into a concave groove 32b provided at the tip of the strainer mounting body 32 on the back side of each ring. A fitting groove 33b for fitting the circumferential end of the strainer screen 32a is provided on the circumference.

  For mounting on the strainer mounting body 32, the engagement protrusion 33a of one of the two retaining rings 33A is fitted into the concave groove 32b of the mounting body 32, and the half peripheral edge of the strainer screen 32a is inserted into the insertion groove 33b. The other retaining ring 33B is pressed against the fitting groove 33b so that the other half-circumferential end of the strainer screen 32a is fitted, and at the same time, the engaging protrusion 33a is fitted into the concave groove 32b of the mounting body 32 and fitted together with the mounting body 32. The fitting body 32 is inserted into the frame 13 and screwed into the fitting frame 13. Thereby, the outer periphery of 33A and B is regulated and fixed to the inner periphery of the fitting frame.

  The strainer screen 32a may have a flat plate shape, but when the central part bulges out in a straw hat shape and bulges to the primary side, the filtered dust does not stop at the center of the screen that closes the water channel by the flow pressure. Is pressed and accumulated. The material of the screen may be a metal such as a wire mesh, but if it is a synthetic resin, the molding surface is easy and the above effects can be exhibited better.

  By turning the ball valve 2 approximately 45 degrees, the water passage to the check valve chamber 22a is closed, and the water supply from the primary side water supply passage 11 flows into the bypass flow passage 4 through the ball valve chamber 22b to the secondary side. The check valve check performance is checked by passing water and opening the check plug 5 set as a check performance check mechanism between the ball valve 2 and the check valve unit 3.

  That is, since the flow path is not closed in the check valve chamber 22a by closing the water passage to the check valve chamber 22a, there is no overflow from the check plug opening if the check performance is perfect. If the performance is incomplete, a backflow pressure is applied to the residual pressure in the check valve chamber 22a and overflow occurs from the check plug opening, so that a check performance failure can be immediately detected.

  In addition, if water pressure is applied through the check plug 5 in the above state, a water pressure test for checking the leakage of the plug main body can be performed without water interruption. Note that the check performance check mechanism set between the ball valve 2 and the check valve unit 3 may be a pressure relief hole and a simple plug or the like, but various ball plugs incorporating a ball valve as shown in FIG. It can also be used for checking operations.

  The ball stopper used as the check performance check mechanism 5 is provided with a joining mechanism 52 for joining a hydraulic pressure tester or the like to one of the stopper bodies 51, and an operation mechanism 54 for a ball valve 53 built in the other, and the lower part is a body stopper valve. It becomes the junction part 55 with.

  Since the present invention is configured as described above, it is possible to check the backflow prevention performance by applying a back pressure to the wearing check valve only by operating the main plug without stopping the water supply. Since the mechanical part of the plug barrel can be disassembled simply by unscrewing, the strainer and check valve unit can be easily replaced and maintained.

1 shows a backflow prevention water stop cock according to an embodiment of the present invention, and is a side view in which the main part of the structure is a longitudinal section. Similarly, a cross-sectional plan view showing the state in which the main valve ball valve of the backflow prevention stop cock is turned halfway to switch the water supply to the bypass flow path. Similarly, a cross-sectional plan view showing a state in which water supply is stopped by fully turning the main valve ball valve of the backflow prevention water stop cock Similarly, a longitudinal side view showing the structure of a ball plug used as a check plug for a backflow prevention water stop cock 1 is a longitudinal side view showing the structure of a check valve unit according to an embodiment of the present invention. Similarly, an exploded view of the strainer screen and retaining ring showing the fitting relationship between the strainer screen and retaining ring attached to the tip of the check valve unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stop cock main body 11 Primary side water supply path 12 Secondary side water flow path 13 Fitting frame 13a which accommodates a non-return valve unit Female screw 13b of inner periphery of fitting frame Male screw 13c of outer periphery of strainer mounting body Strainer mounting Body O-ring fitting 2 Ball valve 21 Ball valve water hole 21a Ball valve water hole primary side opening 21b Ball valve water hole secondary side opening 22a Check valve unit valve chamber 22b Ball valve chamber 23 Ball valve valve outlet 24 Ball valve operation handle 3 Check valve unit 31 Check valve cartridge 32 Strainer mounting body 32a Strainer screen 32b Groove 33 provided at the tip of the strainer mounting body Strainer Screen retaining ring 33A One split ring 33B One split ring 33B The other retaining ring 33a Engagement protrusion that fits with the strainer mounting body 3b Insertion groove 4 into which the peripheral end of the strainer screen is inserted 4 Bypass flow path 41 Telescopic pipe 42 for connecting the secondary side pipe 42 Cap nut 5 for fastening the telescopic pipe 5 Check plug 51 for checking the non-return performance 51 Ball stopper device joint mechanism 53 Ball stopper ball valve 54 Ball stopper ball valve operation mechanism 55 Joint with main body stop cock

Claims (7)

  The primary side opening diameter of the ball valve water passage hole is made large and the secondary side opening diameter is made small so that when the ball valve is rotated by a predetermined angle, the secondary side water passage is closed and the primary side water passage becomes a semi-open state. In addition, a bypass passage is established in which the water passage secondary side opening that is removed from the secondary side water passage by rotation of the ball valve by a predetermined angle communicates with the secondary side rear side of the check valve, and the ball valve Check valve, which has a check performance check mechanism between the check valve and the check valve   The rear part of the secondary side of the valve box body that houses the ball valve is configured as a fitting frame that detachably accommodates the check valve unit, and an expansion tube that joins the secondary pipe to the fitting frame. The backflow prevention water stop cock according to claim 1, wherein the fitting frame is detachably coupled to cover the fitting frame.   The backflow prevention water stop valve according to claim 1 or 2, wherein a strainer mounting body for detachably mounting a strainer screen is set at a primary end of the check valve unit.   4. The backflow prevention device according to claim 3, wherein the strainer screen is attached to the strainer-attached body by a retaining ring that is fitted with the strainer screen and the tip of the strainer-attached body sandwiched from both sides. Water faucet   The backflow prevention water stop cock according to claim 3 or 4, wherein a central portion of the strainer screen is bulged to the primary side.   6. The check valve according to claim 3, wherein the check performance check mechanism set between the ball valve and the check valve is a ball plug.   Formed on the primary side of the check valve cartridge is a cylindrical strainer mounting body with a fitting mechanism for the inner periphery of the water channel and an O-ring fitting, and a strainer screen is detachably mounted at the tip of the strainer mounting body. Check valve unit

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