JPH10169809A - Pressure-reducing type check valve for cold area - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve an inconvenience of freezing of residual water by providing two operation rods to forcibly open two check valves from the outside of a valve casing when water is discharged, and inclining the non-return valves as large as possible on the downstream side. SOLUTION: In a pressure-reducing type check valve to be used for water supply to higher floors, in particular, a check valve to be used in cold areas, a non-return valve seat 7 is arranged between a primary chamber 5 and an intermediate chamber 6, and a non-return valve seat 9 is arranged between the intermediate chamber 6 and a secondary chamber 8 respectively, and a primary bypass passage 11 is provided between the primary chamber 5 and a relief valve seat chamber 10, and a secondary bypass passage 12 and a secondary relief valve seat 13 are provided between the intermediate chamber 6 and an atmospheric vent 4, respectively. Non-return valves 14, 15 are provided so as to be closely attached to the non-return valves 7, 9, and urged to the closing position by check springs 20, 21. The non-return valves 14, 15 are provided with guide parts 22, 23 on their upper end, and their lower end parts are locked to detachment preventive members 24, 25 mounted on a lower end part of operation rods 18, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-reducing check valve used in cold regions.

[0002]

2. Description of the Related Art In recent years, in Japan, direct water supply to high floors has been increasing, and with this, a highly reliable pressure reducing check valve has been used to maintain the safety of water supply.
This is because a relief valve operated by water pressure and spring is provided between the two check valves, and the pressure difference generated between the primary side and the secondary side due to the strength of the spring of the check valve is controlled by the reverse pressure and the reverse siphon. When the value is reduced to a value, the water on the secondary side is released from the relief valve to make up the space, and its reliability is said to be comparable to the water discharge space.

[0003] However, in winter, there has been no material suitable for use in a cold region where water may freeze, and when it is absolutely necessary to use the device in such an atmosphere, a thermal insulation measure must be taken as a measure to prevent freezing. In practice, they are practically seldom used because of limited use and high costs.

[0004]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a decompression type check valve for a cold district which can be used by performing a drainage operation without taking heat treatment. After draining, residual water freezes when water re-flows, blocking passages, preventing water from leaking out, or eliminating residual water freezing and impairing or damaging valve functions. It is like that.

[0005]

Therefore, according to the present invention, there are provided two operation rods for forcibly opening the two check valves from the outside of the valve box at the time of draining water, and the check valves are disposed on the downstream side. The position of the valve seat is lowered by tilting the valve as much as possible to reduce residual water during drainage.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The two check valves are provided with a 45 ° inclination on the downstream side so as to minimize the head loss and
Although the position of the valve seat is lowered to reduce the amount of water remaining in the valve box, the angle is not limited to this angle.

The check valve and the operating rod are not connected coaxially, but are separated from each other. For example, the operating rod having a tapered tip from the lateral side of the valve box is moved up and down by a screw or lever, or is eccentric. The check valve can be moved upward only by rotating using the operation rod provided with the part, and in any case, the check valve is returned by a spring when the operation rod is made to pass water. Also, the check valve is prevented from impairing its function by the operation rod when the water is flowing.

Attach a commercially available wing nut to the tip of the operating rod,
Although the handle is used, it is needless to say that another handle may be used, or a driver or the like may be used without using the handle.

When the present invention is applied to a type in which a relief valve is operated by a diaphragm, such as a commercially available product,
At the time of draining, it is necessary to adopt a structure that allows the water of the diaphragm part to be drained, and although the labor is increased, a drain valve can be separately provided at that part.

[0010] The valve seat of the check valve and the valve seat on the secondary side of the relief valve are formed integrally with the valve box. However, during repair, the valve seat is damaged and the valve box itself is replaced. In order to avoid this, the valve seat can be detached independently, or a cartridge type can be used so that the valve seat can be inserted and removed together with the check valve and the relief valve.

[0011]

FIG. 1 shows an embodiment of the present invention.
Is a valve box having an inflow port 2 at the left end, an outflow port 3 at the right end, and an atmosphere opening port 4 at the lower end. A first check valve seat 7 inclined 45 ° in the direction of the outlet 3 between the primary chamber 5 and the intermediate chamber 6;
Similarly, a second check valve seat 9 which is also inclined is disposed between the intermediate chamber 6 and the secondary chamber 8, and a primary side bypass passage 11 is provided between the primary chamber 5 and a relief valve chamber 10 below the primary chamber 5, and an intermediate chamber The secondary side bypass passage 12 and the secondary side relief valve seat 13 are provided between 6 and the atmosphere opening port 4.

Reference numeral 14 denotes a first check valve, and reference numeral 15 denotes a second check valve. A first check packing 16 and a second check valve which are in close contact with the first check valve seat 7 and the second check valve seat 9, respectively. First stop rod 17 is attached to first operation rod 18 and second operation rod 19.
With the check spring 20, the weaker second check spring 21,
Pressed downward. The first check valve 14 and the second check valve 15 have guide portions 22 and 23 at the upper ends, and the lower ends thereof are fixed to the retaining members 24 and 25 attached to the lower ends of the operating rods 18 and 19, respectively. The operation rods 18 and 19 are connected so that they can freely move up and down without greatly shifting the axis.

Although commercially available O-rings are used for the retaining members 24 and 25, a metal elastic ring with the ends cut off may be used, or instead of using rings, the portions may be used instead. There is also a method of protruding the pin, and conversely, protruding the pin from the guide portions 22 and 23,
8 and 19 may be provided with longitudinal grooves, in which case the non-return valves 14 and 15 are restricted from rotating, so that valve wear,
There is also an effect that generation of vibration and the like can be prevented.

O-rings 26 and 27 are mounted on the operation rods 18 and 19, and cylinders 28 and 29 provided on the valve box 1 are slid. An upper cover 30 serving as a stopper is provided at the upper end of the valve box 1. 31 are connected to the upper lids 30, 31
Is extended downward to provide a cylinder inside,
19 may slide on the cylinder. Commercially available wing nuts are attached to the upper ends of the operation rods 18 and 19 to form handles 32 and 33, respectively.

A relief valve box 34 is threadably connected to the relief valve chamber 10 so as to be adjustable. A primary relief valve seat 35 having the same diameter as the secondary relief valve seat 13 is provided therein, and a left end is provided at the left end. A plug 36 is connected, and the primary pressure introducing hole 3 is provided on the right side.
I wear 7. A first valve closing the primary relief valve seat 35 and the secondary relief valve seat 13 inside the relief valve box 34.
The relief valve 40 equipped with the relief packing 38 and the second relief packing 39 is always pressed to the primary side by the relief spring 41.

The figure shows a water-stop state in which the end faucet is stopped. In this state, the pressure P in the primary chamber 5 and the intermediate chamber 6 is reduced.
The first check valve spring and the second check valve are arranged so that the first check valve 19 opens at a pressure of at least 710 mm water column from the upstream side and at a pressure as low as possible so that the relation between P1 and P2 is about 35 to 50 KPa. Determine the strength of the spring. This P1 and P2
The relief valve 40 presses the relief spring 41 due to the pressure difference between the first relief packing 38 and the primary relief valve seat 35.
In the state where the second relief packing 39 is in close contact with the secondary side relief valve seat 13 to prevent water leakage to the atmosphere opening port 4 side, and the valve starts to be opened when P2 is at least 14 KPa lower than P1. Thus, the strength of the relief spring 41 is determined, and the position of the relief valve box 34 is adjusted.

When the faucet is opened from this state, the water in the primary chamber 5 is decompressed by the first check valve 14 and enters the intermediate chamber 6, and the second check valve 19 is further raised to cause the secondary chamber 8 to rise. And reaches the faucet through a downstream pipe (not shown) connected to the outlet 3. If the faucet is closed, the check spring 20,2
1, the check valves 14 and 15 return to the state shown in FIG.

When the pressure at the outlet 3 becomes higher than the pressure at the inlet 2, that is, when a so-called back pressure phenomenon occurs, as long as the second check valve 15 is operating normally, the pressure in the secondary chamber 8 is maintained. Although water does not flow back into the intermediate chamber 6, if foreign matter gets stuck in the second check valve 15 and water leaks, the pressure difference between P1 and P2 becomes small, and at least 14 KPa Is reached, the relief valve 40 is pressed by the relief spring 41, the second relief packing 39 is separated from the secondary relief valve seat 13, and the backflow water is discharged from the atmosphere opening port 4. At this time, since the first relief packing 38 is simultaneously separated from the primary side relief valve seat 35, water in the relief valve chamber 10 is also discharged from the atmosphere opening port 4, but this is a small amount, which actually causes a problem. Not something. At this time, if a commercially available backup ring 42 is attached to the relief valve 40, the leakage amount can be further reduced without increasing the frictional resistance.

When water is cut off due to main pipe work and the pressure on the primary chamber 5 side drops below the atmospheric pressure, water in the pipe downstream of the outlet 3 tries to flow back to the primary chamber 5 side due to the reverse siphon phenomenon. Again, backflow is prevented by the first check valve 14 and the second check valve 15, and at the same time, the relief valve 40 moves to the left as much as possible by the relief spring 41 and the negative pressure, and contacts the right end of the relief valve box 34. Stop. At this time, if there is a leak due to the failure of the first check valve 14, air is sucked from the atmosphere opening port 4 to reduce the negative pressure in the piping.

In winter, when it is desired to drain water, an antifreeze feed cock or a drain valve installed in the upstream pipe is operated to drain the water in the upstream pipe of the pressure-reducing check valve. 33, the first and second operation rods 18 and 19 are rotated.
The first and second check valves 14 and 15 are also raised by being locked by the retaining members 24 and 25, and the first and second check packings 16 and 17 are moved up and down by the screws. (2) The valve is released from the check valve seats 7 and 9, and at this time, since the relief valve 40 is also released from the relief valve seats 13 and 35, all the water in the intermediate chamber 6 is discharged from the atmosphere opening port 4 and flows simultaneously. The water in the outlet 3 side pipe is also discharged from the atmosphere opening port 4 to a position below the second check valve seat 9.

The relief spring 41 is provided with the relief valve 4 in a natural state.
0 is so strong that it does not contact the right end of the relief valve box 34, so that the primary side bypass passage 11 and the relief valve chamber 1
The water in 0 is also discharged from the atmosphere opening 4 little by little to the position below the primary relief valve seat 35.

In other words, there is no water residue such that the residual water freezes and damages the valve box, and the check valve seats 7 and 9 are sealed with ice and water does not come out when water is re-flowed. Does not occur.

When the operating rods 18 and 19 are lowered by rotating the handles 32 and 33 in the reverse direction, the check valves 14 and 15 are also lowered by the check springs 20 and 21 to return to the former position.

[0024]

As described above, in the present invention, at the time of drainage, the two check valves are forcibly opened from the outside of the valve box, so that the check valve seat is largely inclined in the direction of the outlet. In combination with the fact that the space between the relief valve chamber provided at the lower part and the atmosphere opening port provided at the lowermost part is opened,
The residual water in the valve box is small, and there is no water when re-watering, and the valve box and other parts will not be damaged or lose their function due to freezing of residual water, so heat insulation measures There is an effect that it can be used in cold regions without taking any measures.

[Brief description of the drawings]

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

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Valve box 2 Inlet 3 Outlet 4 Atmospheric opening 5 Primary room 6 Intermediate room 7 First check valve seat 8 Secondary room 9 Second check valve seat 10 Relief room 11 Primary side bypass passage 12 Secondary side bypass Road 13 Secondary-side relief valve seat 14 First check valve 15 Second check valve 16 First check packing 17 Second check packing 18 First operation rod 19 Second operation rod 20 First check spring 21 First 2 Check spring 22, 23 Guide part 24, 25 Retaining member 26, 27 O
Ring 28, 29 Cylinder 30, 31 Upper lid 32, 33 Handle 34 Relief valve box 35 Primary relief valve seat 36 Plug 37 Primary pressure introducing hole 38 First relief packing 39 Second relief packing 40 Relief valve 41 Relief spring 42 Backup ring

Claims (3)

[Claims] A first check valve on the primary side and a second check valve on the secondary side, which operate independently, are provided inside the valve box, and the pressure in the primary chamber on the upstream side of the first check valve is controlled. A check valve having a relief valve which operates by receiving a pressure of the intermediate chamber lower than a pressure of the primary chamber by a first check spring for pressing the first check valve, and which can shut off a passage to the atmosphere opening port; In the apparatus, the first and second check valves are installed obliquely to the downstream side and first and second operation rods for forcibly opening the respective check valves from outside the valve box are provided. Features a decompression type check valve for cold districts. 2. The first and second check valves are first and second check valves, respectively.
2. The pressure-reducing type backflow prevention valve for a cold district according to claim 1, wherein the second operation rod is vertically movably connected to each other, and both operation rods are moved up and down in the valve box by screws. 3. The relief valve has a first relief packing which abuts a pressure from a primary chamber on a primary relief valve seat to stop water, and a pressure from the intermediate chamber which has the same diameter as the primary relief valve seat. 3. The pressure reducing check valve for a cold district according to claim 1, further comprising a second relief packing which comes into contact with the secondary relief valve seat to stop water and is constantly pressed toward the primary chamber by a relief spring.