JPH1061800A - Drainage type check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drainage type check valve without a reverse flow even when a piping length in the downstream of the check valve is large in a vertical length. SOLUTION: In the drainage type check valve, between a check valve seat 4 and a bypass port 6 with water flowing out to a bypass path 7, a cylinder 5 is interposed, a drain valve seat 4 provided in the vicinity of the bypass port 6 is formed in a diameter smaller than a cylinder 5, a drain valve 17 closing the drain valve seat 4 and an auxiliary valve 12 fitted to the cylinder 5 at drainage time to give moving force to the drain valve 17 in an opening direction based on a diametric difference between the cylinder 5 and the drain valve seat 4 are received in a valve case 1, and, in any of the drain valve 17 or the auxiliary valve 12, a non-return packing 13 closing the check valve seat 4 is mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain check valve mainly used in cold regions, and more particularly to an improvement of Japanese Utility Model Application No. 63-14391 by the same applicant.

[0002]

2. Description of the Related Art Conventionally, a check valve for cold districts needs to release a check for preventing backflow at the time of drainage. Therefore, a check valve which does not require such a check has been desired. This is a cited example, which does not require an operation for releasing the check valve, and has a feature that water or hot water in the pipe after the check valve is not discharged to the draining device side.

[0003]

However, in the above-mentioned structure, when the vertical length (head) of the piping after the check valve is large, the water pressure (head pressure) acting on the drain valve in the closing direction also increases accordingly. However, there is a problem that the drain valve does not float until a certain head pressure is reached when draining, and backflow is permitted. Therefore, the head must be restricted, which is very inconvenient during actual use. Had become something. This is true for drainage check valves that are used outside of cold regions because they are safer than normal check valves, and in any case, an early solution is desired. Was.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems, and has a cylinder interposed between a check valve seat and a bypass port through which water flows to a bypass passage.
A drain valve seat formed in the vicinity of the bypass port is formed to have a smaller diameter than the cylinder, and a drain valve for closing the drain valve seat is fitted to the cylinder at the time of drainage to move based on a diameter difference between the cylinder and the drain valve seat. An auxiliary valve that applies force to the drain valve is housed in a valve box, and one of the drain valve and the auxiliary valve is provided with a check packing that closes the check valve seat. Regardless, it is intended to achieve its initial purpose.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show an embodiment according to a vertical pipe which occupies most of the installation examples in a cold region. The valve may be positioned at an angle of approximately 45 degrees with respect to the inlet and outlet. The auxiliary valve separates from the cylinder during water flow to secure a flow path, but when draining or negative pressure is generated, a spring,
Moved by buoyancy or water flow and fitted to the cylinder to prevent most of the water in the outflow side piping from flowing back to the inflow side and locked using the area difference with the drain valve seat. The drain valve is moved so that the water in the outlet pipe is discharged from the drain port.

As shown in FIG. 1, an O-ring may be used as a drain valve seat, and conversely, a packing may be attached to the drain valve.
As shown in FIG. 3, the drain valve seat can be made cylindrical. If a drainage device such as an antifreeze water tap is installed upstream of the inlet, an intake valve is provided between the inlet and the check valve seat to allow the water in the inlet-side piping to drain smoothly from the drainer. Although it is possible to do so, if there is no drainage device on the upstream side other than the cold region, it is normal to not provide an intake valve.

After draining, if the auxiliary valve is not separated from the cylinder, water will not come out when re-flowing due to freezing. If the self-weight or self-weight cannot be expected, the auxiliary valve will be completely removed from the cylinder by the force of the spring. Separation, or at least the main channel, needs to be separated. Of course, when a drainage device such as an antifreeze water faucet is not provided upstream of the check valve, and the check valve itself is installed in an atmosphere that does not freeze, it is not necessary.

[0008] Since the drain valve is normally in close contact with the drain valve seat, there is a risk that the drain valve will stick due to aging and will not drain. Therefore, either the drain valve or the drain valve seat is made of tetrafluoroethylene resin (hereinafter referred to as Teflon). It is desirable to use the excellent non-adhesiveness to prevent sticking, but this is not necessarily the case.

[0009]

Embodiments will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a valve box, which has an inflow port 2 and an outflow port 3 on the same axis, and a check valve seat 4, a cylinder 5, and a bypass port 6 which are directed downward from the upstream side to the downstream side of the flow. , Bypass paths 7 are provided. A guide cylinder 8 having the same diameter as the cylinder 5 is provided below the bypass port 6, and a drain plug 9 is further connected below the guide cylinder 8. Drain plug 9
Has a drain port 10 at the lower end and an O-ring at the upper end to form a drain valve seat 11.

Reference numeral 12 denotes an auxiliary valve formed of a resin having a specific gravity of less than 1, such as polyethylene or polypropylene.
The check action is also performed. Inside, a storage chamber 14 having a closed upper end is bored, and a lateral hole 15 is formed laterally and a step 16 is formed at the lower end.

Reference numeral 17 denotes a drain valve made of Teflon, which is provided with a projection 18 and a split portion 19 at the upper end, and is connected to the accommodation chamber 14 so as not to be separated from the accommodation chamber 14 by being narrowed at the projection. A guide portion 20 is provided at the lower end, and a conical spring 21 presses the tip of the guide portion 20 upward. In addition,
Reference numeral 22 denotes an intake valve installed in the upper 45-degree direction.

The figure shows a state in which the faucet at the end of the pipe is closed and water is not flowing, that is, a water stop state. When the faucet is opened, water from the inflow port 1 passes through the check valve seat 4. The auxiliary valve 11 is pushed down, and flows out from the outflow port 3 into the downstream pipe through the bypass port 6 and the bypass path 7. At this time, due to the water pressure, the drain valve 17 overcomes the pressing force of the spring 21 and is in close contact with the drain valve seat 11, so that there is no leakage from the drain port 10.

When water is drained by operating the antifreeze water tap in this state, the auxiliary valve 12 immediately rises due to the buoyancy and the flow of water, and is fitted into the cylinder 5 to be in the state shown in FIG. At this time, the flow of the water on the side of the outlet 3 to the check valve seat 4 is largely blocked, and the cylinder 5 has a larger diameter than the drain valve seat 11, so that the difference in the area between the outlet 5 and the secondary The auxiliary valve 12 and the step 16 receive the protrusion 1 by receiving the force multiplied by the head pressure of the pipe.
The drain valve 17 with the lock 8 is also raised, and the check packing 13 is in close contact with the check valve seat 4 to prevent the water in the outlet pipe from flowing back to the inlet 1 side, The water in the pipe is discharged from the drain 10. In addition, before the auxiliary valve 12 is lifted from the guide cylinder 8 while being lifted,
Since the auxiliary valve 12 is fitted to the cylinder 5, the auxiliary valve 12 can smoothly rise along the axis.

That is, since the upward water pressure acting on the auxiliary valve 12 is larger than the downward water pressure acting on the drain valve 17, when the head becomes high as in the cited example, the water level becomes constant. There is no occurrence of an accident that the water is not discharged from the drain port 10 until it lowers and flows backward to the inlet side.
When the water level further decreases and the auxiliary valve 12 cannot maintain the rise due to buoyancy, the auxiliary valve 12 falls by its own weight until it comes into contact with the drain plug 9.
1 does not adhere to the water, water flows from the side hole 15 through the auxiliary valve 12
7 are all discharged from the drain port 10 through the gap 7.

After draining, the auxiliary valve 12 is completely separated from the cylinder 5. Therefore, when water is re-flowed, there is no accident that the passage is closed due to freezing and water does not flow. In addition, the water in the inflow-side pipe is discharged into the ground from the drain port of the antifreeze faucet while sucking in air from the intake valve 22.

The above description has been made on the case where the antifreeze water tap is operated to drain the water. However, even when a negative pressure is generated at the inlet side due to the interruption of the main pipe or the like during the passage of water, the outflow side piping is similarly operated. The backflow of the water inside is prevented, and the water is discharged from the drain port 10.

FIG. 2 shows another embodiment of the present invention. In this figure, the check valve 13 is provided at the upper end of the drain valve 17 instead of attaching the check packing 13 to the auxiliary valve 12, and the lower end is provided at the lower end. Is fitted with an O-ring 23 and is seated on a drain valve seat 11 made of Teflon fixed by a drain plug 9. Since the guide portion 20 is provided with a horizontal hole 15 and a vertical hole 24, and the guide portion 20 is made sufficiently long so as to be guided firmly, the guide cylinder 8 in FIG. 1 when the auxiliary valve 12 moves up and down is omitted. And drain valve 17
It moves up and down as a guide. Auxiliary valve 12
1 is formed of a resin having a specific gravity smaller than 1, and the drain valve 17 is pressed upward by a spring 21 as in FIG.

At the lower end of the drain plug 9, a water stop valve 25 is provided to be drilled around the drain port 10, and at the upper end, a water stop O-ring 26 is attached. In such a case, water is stopped. Reference numeral 27 denotes a stopper O-ring, which is mounted after the water stop valve 25 is screwed.

The figure shows a state after the drainage is completed. The drainage valve 17 is separated from the drainage valve seat 11 by being pressed by the spring 21, but the auxiliary valve 12 does not receive buoyancy. She is sitting on seat 11. When the water stops, the auxiliary valve 12 is fitted to the cylinder 5 with the upper end of the auxiliary valve 12 in contact with the projection 18 formed on the drain valve 17 as shown in FIG.

FIG. 3 shows an embodiment of the present invention in which the check valve is installed at a place where it does not freeze. The inlet 2 and the taper at the end of the check valve seat 28 screwed to the inlet are screwed. Since the check valve seat 4, the cylinder 5, and the cylindrical drain valve seat 11 and the outlet 3 having a smaller diameter than the cylinder 5 are provided on the same axis, the loss resistance can be reduced accordingly. It should be noted that two bypass paths 7 may be provided in the direction perpendicular to the plane of the paper, so that the loss resistance can be further reduced.

An O-ring check packing 13 is mounted on the auxiliary valve 12, and several guide blades 29 are provided downstream thereof so as not to be separated from the cylinder 5. A one-way sealing Y packing 30 for closing the drain valve seat 11 is attached to the drain valve 17 locked to the auxiliary valve 12 by the projection 18 via the spring 21 so as to minimize sliding resistance. ing.

The figure shows the state when a negative pressure is generated. The check packing 13 contacts the check valve seat 4 to prevent back flow,
The drain valve 17 is separated from the drain valve seat 11, and the water in the outflow-side pipe is discharged from the drain port 10. When a negative pressure is generated in the water-flowing state, the cylindrical portion downstream of the guide vanes 29 is fitted into the cylinder 5 by being pressed by the spring 21, and the drain valve 17 is moved by the area difference between the cylinder 5 and the check valve seat 11. Although it is made to separate from the drain valve seat 11, the spring 21 can be omitted and the auxiliary valve 12 can be moved by the flow of water. Since it falls, the spring 21 may be omitted.

When the embodiment of FIG. 3 is installed in a freezing atmosphere, similarly to the embodiments of FIGS. 1 and 2, the spring 21 is omitted, and instead, the check valve seat body 28 and the auxiliary valve 12 are connected. The auxiliary valve 12 may be moved downstream by the spring after the drainage is completed.

[0024]

As described above, in the present invention, when the size of the piping head after the check valve becomes large, the water is not discharged from the drain port but flows backward to the main pipe side. It is possible to provide a drain check valve that can be prevented beforehand, and the water in the outflow pipe is discharged from the check valve.
Compared to a normal check valve, it is safer to mix sewage into the main pipe.If combined with a vacuum breaker installed at a high location on the pipe downstream of the check valve, the effect will be even greater. Can be expected.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a water stop state according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a main part of another embodiment of the present invention in a state where drainage is completed.

FIG. 3 is a longitudinal sectional view showing another embodiment of the present invention when a negative pressure is generated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 2 Inlet 3 Outlet 4 Check valve seat 5 Cylinder 6 Bypass port 7 Bypass path 10 Drain port 11 Drain valve seat 12 Auxiliary valve 13 Check packing 17 Drain valve 21 Spring 22 Intake valve

Claims (1)

[Claims] (1) From the upstream side of the flow to the downstream side,
In the valve box, which has an inlet, a check valve seat, a cylinder, a bypass port, a bypass passage, and an outlet, and a drain valve seat smaller in diameter than the cylinder near the bypass port,
A drain valve that seals the drain valve seat, and an auxiliary valve that fits into the cylinder during drainage and provides the drain valve with an opening-direction moving force based on a diameter difference between the cylinder and the drain valve seat; A drainage check valve in which a check packing for closing the check valve seat is mounted on one of the auxiliary valves.