JPH0979201A - Water hammer preventing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water hammer preventing device that is capable of absorbing water hammer properly, easy to handle and maintain and capable of being produced in smaller size. SOLUTION: This water hammer preventing device is provided with both inflow and outflow ports 104 and 105, and a small diametral throttle part 109 is formed in space between these inflow and outflow ports 104 and 105, while it is equipped with a jet pump 106 provided with a low pressure chamber 111 interconnected to the small diameter throttle part 109 and a gaseous bag 112 with a gas chamber being varied according to a pressure change in this low pressure chamber 111 and partitioned off from this chamber 111, respectively. At the time of feedwater, the low pressure chamber 111 comes to low pressure due to an action of the jet pump 106, whereby the gas bag 112 is prevented from being crushed, and in the case where pressure in the low pressure chamber 111 rises at the time of a water hammer, the gas bag 112 is forcibly pressed and a gaseous body in the gas chamber is compressed, whereby this water hammer is thus absorbable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water hammer preventer for preventing water hammer of a pipe used in a water supply system or the like.

[0002]

2. Description of the Related Art In water supply systems such as buildings, condominiums, apartments and single-family homes, if the water flow in a water supply pipe is momentarily shut off by a faucet or valve, the closed upstream pressure will rise abnormally. , This rising pressure becomes a pressure wave and reciprocates between that point and the water supply source. Such a pressure rise is called a water hammer, and when this water hammer becomes excessive, it not only vibrates the pipes, joints, valves, and equipment, and generates an impact sound, This may cause water leakage.

To prevent this, a water hammer preventer is generally used. The water hammer prevention device absorbs and reduces water hammer.In the conventional case, the air chamber is branched to communicate with the water supply pipe, and when the pressure in the water supply pipe rises, the air in the air chamber is It was compressed to absorb the increase in water pressure. However, such a water hammer preventer has a drawback that the air in the air chamber is dissolved in the water and gradually decreases because the air chamber is in direct contact with the water in the water supply pipe. Therefore, it is necessary to replenish the air in the air chamber regularly.

In order to prevent such a problem, for example, a water hammer preventer having a structure shown in Japanese Utility Model Publication No. 6-43521 has been used. The water hammer preventer described in the above publication is developed by the present applicant, and the inside of the body connected to the water supply pipe is partitioned by a diaphragm, and one chamber is a liquid chamber connected to the water supply pipe. In addition, the other chamber is an air chamber in which air is enclosed, and this air chamber is configured to accommodate an elastic member. In the water hammer preventer with such a structure, when a water hammer occurs in the water supply pipe and the water pressure rises abnormally, this pressure acts on the diaphragm through the liquid chamber of the water hammer preventer so that the diaphragm is pushed. become. When the diaphragm is pressed, the air and the elastic member are compressed, whereby the pressure increase in the water supply pipe is absorbed and alleviated.

According to this structure, since the inside of the container is partitioned by the diaphragm, the problem that the air in the air chamber is dissolved in water is prevented.

[0006]

However, the water hammer preventer having the conventional structure as described above has the following problems.

Normally, air at atmospheric pressure is sealed in the air chamber, and if this water hammer preventer is connected to the water supply pipe, the water pressure of the water supply pipe is applied to the diaphragm even when no water is flowing, and this water pressure is large. Since the pressure is higher than the atmospheric pressure, the air in the air chamber is compressed and the volume in the air chamber is reduced.

That is, in the water hammer preventer as described above, the water supply pressure is applied to the diaphragm when the water is flowing through the water supply pipe, and this pressure compresses the air in the air chamber to reduce the volume in the air chamber. Therefore, the volume of the air chamber becomes smaller than the initially set volume, which causes a problem that the water hammer absorption capacity is reduced.

Particularly, when the water supply pressure in the water supply pipe fluctuates and the water pressure becomes high, the diaphragm is further pushed and the volume in the air chamber is greatly reduced, and when the water hammer occurs, the absorption capacity thereof is significantly lowered. There is a drawback that it ends up.

In order to prevent this and absorb a large water hammer, it is necessary to form a large volume in the air chamber in advance, which causes a problem that the water hammer preventer becomes large. .

The present invention has been made in view of the above circumstances. An object of the present invention is to secure a sufficiently large volume of a gas chamber to absorb a water hammer satisfactorily and to make it easy to handle and maintain and downsize. It is intended to provide a water hammer protection device.

[0012]

In order to solve the above problems, the invention of claim 1 has an inflow port and an outflow port, and a small-diameter throttle portion is formed between the inflow port and the outflow port. At the same time, a jet pump provided with a low-pressure chamber communicating with the small-diameter throttle portion and having a low pressure when the liquid is sucked into the small-diameter throttle portion when the liquid flows from the inflow port to the outflow port; It is characterized in that it is installed and has a gas chamber formed therein, and a gas bag that is elastically deformable according to the pressure change of the low pressure chamber.

According to the structure of claim 1, the velocity of the fluid flowing from the inflow port toward the outflow port is accelerated when passing through the small diameter throttle portion, and the pressure in the small diameter throttle portion becomes low. For this reason,
The liquid in the low-pressure chamber is sucked into the small-diameter throttle portion, and the pressure in the low-pressure chamber drops.

Since an elastically deformable gas bag having a gas chamber formed therein is provided in such a low pressure chamber, when a water hammer occurs on the side of the water supply pipe to which the jet pump is connected,
The increase in the water supply pressure is added to the gas bag, which is pushed and the gas in the gas chamber is compressed. Therefore, the water hammer can be absorbed. When water is being supplied from the water supply piping side, the jet pump prevents the supply pressure from being applied to the low-pressure chamber, so the gas chamber is not pushed and the volume does not decrease. Can be secured to a large extent, and a large absorption capacity can be obtained.

According to a second aspect of the present invention, there is an inflow port and an outflow port, and a small-diameter throttle part is formed between the inflow port and the outflow port, and the small-diameter throttle part communicates with the small-diameter throttle part. A jet pump provided with a low pressure chamber whose pressure is reduced by the liquid being sucked into the small-diameter throttle portion when the liquid flows through the outlet; an absorption case connected to the low pressure chamber; And a movable wall which is divided into a liquid chamber and a gas chamber which are continuous with each other and which fluctuates in accordance with a change in pressure of the liquid chamber;

The term "movable wall" as used herein refers to a partition wall that deforms or fluctuates according to a change in pressure.
It is represented by diaphragms and bellows.

According to the structure of the second aspect, since the absorption case is connected to the low pressure chamber of the jet pump and the movable wall is provided in this absorption case, the volume of the gas chamber can be made large and water can be supplied to the movable wall. Pressure can be prevented from being applied, the volume of the gas chamber can be kept large, and the ability to absorb water hammer can be increased.

According to a third aspect of the present invention, air is contained in the gas chamber, and air supply means is provided for automatically supplying air to the gas chamber when the pressure in the gas chamber becomes lower than atmospheric pressure. The water hammer preventer according to claim 2, wherein the water hammer preventer is provided.

According to the third aspect of the invention, when the pressure in the gas chamber becomes lower than the atmospheric pressure, the air is automatically replenished, the volume of the gas chamber can be secured large, and the gas chamber can be secured. Can be kept above atmospheric pressure. Moreover, since it is not necessary to replenish air, it is easy to handle.

A fourth aspect of the invention is the water hammer preventer according to the third aspect, wherein the air supply means is an orifice.

According to the structure of claim 4, since the orifice is used as the air replenishing means, the flow resistance of the air can be changed depending on the diameter of the orifice.
It is possible to adjust the behavior of the movable wall when a water hammer occurs.

According to a fifth aspect of the present invention, the air replenishing means is provided with a check valve for preventing the gas in the gas chamber from flowing out.
It is a water hammer prevention device described in.

According to the structure of the fifth aspect, since the check valve is provided in the orifice, the check valve is closed and the gas in the gas chamber is not released to the outside when a water hammer occurs. Therefore, the volume of the gas chamber can be reliably ensured, the pressure can be maintained at a predetermined level, and the water hammer can be well absorbed.

The invention according to claim 6 is characterized in that an elastic member for pressing the movable wall is provided in the gas chamber, and the water hammer prevention according to any one of claims 2 to 5 is characterized. It is a vessel.

According to the structure of claim 6, since the elastic member is provided in the gas chamber, the volume of the gas chamber for absorbing the water hammer can be secured, and depending on the material and size of the elastic member, the elastic member can be secured. The spring constant of can be arbitrarily set, and various pressures can be dealt with.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a water hammer preventer of the present invention will be described based on each embodiment.

(First Embodiment) FIG. 1 is a view showing a water supply system to which a water hammer preventer is attached, and FIG. 2 is a sectional view of the water hammer preventer according to this embodiment.

Generally, in a water supply system in a building or a condominium, tap water is guided to and stored in a water receiving tank 10 installed in a basement of the building as shown in FIG. The water in the water receiving tank 10 is pumped by the pumping pump 11 through the pumping pipe 12 to the elevated tank 13 temporarily installed on the roof. The water pumped up to the elevated tank 13 is guided to each floor by the water supply conduit 14, and is branched to the kitchen, washroom, bathroom, toilet faucet and water tap 16 by the branch pipes 15 ... Is led.

The water hammer preventer 100 of the present invention is attached to each of the branch pipes 15 ...

The structure of the water hammer preventer 100 is shown in FIG.
It will be explained based on the following. In FIG. 2, reference numeral 101 denotes a casing, and this casing 101 is configured by connecting a body 102 and a cap 103. Cap 103
An inflow port 104 is formed in the body 102, and an outflow port 105 is formed in the body 102.

A jet pump 106 is formed between the inflow port 104 and the outflow port 105. Jet pump 10
6 is an introduction nozzle 107 that is connected to the inflow port 104.
And a spreading nozzle 108 connected to the outflow port 105. The inner end of the introduction nozzle 107 forms a small-diameter throttle portion 109 that has a small diameter. The spreading nozzle 1
08 is provided on the same axis as the introduction nozzle 107, and the inner end of the expansion nozzle 108 is narrowed to a small diameter so as to face the inner end of the introduction nozzle 107.

The inner end of the introduction nozzle 107 and the inner end of the spreading nozzle 108 are separated from each other, and a communication portion 110 is formed between them. In the casing 101, a low pressure chamber 111 is formed around the introduction nozzle 107 and the spreading nozzle 108. The low pressure chamber 111 is connected to the introduction nozzle 10 via the communication part 110.
7 to the small-diameter throttle portion 109.

An air bag 112 is provided in the low pressure chamber 104. The air bag 112 is a cylindrical bag made of rubber or the like and having elasticity capable of expanding and contracting, and air at atmospheric pressure is hermetically sealed therein. One end of the air bag 112 is sandwiched by a tube stopper 113, and the tube stopper 113 is fixed to the cap bottom portion 116 via a nut 114 and a washer 115.

The water hammer preventer 100 having the above structure is
The inflow port 104 and the outflow port 105 are used by being connected to the branch pipe 15. And when water flows in the branch pipe 15,
This water flows from the inlet 104 of the jet pump 106 to the outlet 1
It flows toward 05. In the jet pump 106, the flow velocity becomes faster in the small-diameter throttle portion 109, so that the pressure drops. Therefore, the water in the low pressure chamber 111 is tried to be sucked from the communication portion 110, and the pressure in the low pressure chamber 111 becomes low.
Therefore, no water supply pressure is applied to the air bag 112 installed in the low pressure chamber 111, and the atmosphere is kept at a pressure lower than the water supply pressure, so that the air bag 112 is not crushed.

When the faucet or the water tap 16 is closed, the water pressure on the upstream side of the tap increases and a so-called water hammer occurs. This increase in pressure is transmitted to the low pressure chamber 111 through the communication portion 110 of the jet pump 106, and the pressure in the low pressure chamber 111 rises.
However, since the air bag 112 is housed in the low pressure chamber 111, the air bag 112 is pushed and the internal air is compressed, so that the above pressure increase is absorbed. Therefore, the water hammer will be absorbed and mitigated.

Since the air bladder 112 is provided in the low pressure chamber 111 of the jet pump 106, the air bladder 112 is not crushed during the water supply as described above.
It is possible to secure a large volume inside 2, so that when the water hammer occurs, the increased water pressure can be favorably absorbed by the air in the gas chamber. In addition, the air bag 112 is placed in the low pressure chamber 111.
Since the water hammer prevention device 100 is provided, the shape of the water hammer preventer 100 can be made compact.

(Second Embodiment) FIG. 3 is a sectional view of a water hammer preventer according to the second embodiment.

The water hammer preventer 200 shown in FIG. 3 is constructed by attaching an absorption case 201 to the casing 101 of the jet pump 106 shown in the first embodiment. A diaphragm 202 as a movable wall is provided in the absorption case 201, and the diaphragm 202 divides the inside of the absorption case 201 into a liquid chamber 203 and a gas chamber 204. The liquid chamber 203 is the low pressure chamber 1 in the casing 101.
It is formed so as to communicate with the low pressure chamber 111 and to have a pressure equal to that of the low pressure chamber 111, and atmospheric air is sealed in the gas chamber 204. The upper end of the absorption case 201 is closed by the upper cap 205, and the diaphragm 20
2 has an upper end thereof sandwiched between the upper end of the absorption case 201 and the upper cap 205 to seal the liquid chamber 203 and the gas chamber 204. In the gas chamber 204, a cushioning material 206, which is an elastic member such as foamed synthetic resin formed in a cylindrical shape, is housed as an elastic member.

The water hammer preventer 200 having the above structure is
When water flows in the branch pipe 15, the pressure in the low pressure chamber 111 decreases, and the liquid chamber 203 communicating with the low pressure chamber 111.
The internal pressure also drops. Therefore, the diaphragm 202 moves to the liquid chamber 203 side, and the volume in the gas chamber 204 can be secured.

When a water hammer occurs in the branch pipe 15, this water pressure is applied to the liquid chamber 203 through the communicating portion 110 and the low pressure chamber 111, and the diaphragm 202 is pushed, so that the air in the gas chamber 204 and the cushioning material. Press 206. Therefore, the increase in water pressure can be absorbed by the compressive deformation of the air and the cushioning material 206.

In the case of this embodiment, the diaphragm 2 is attached to the movable wall.
Since 02 is used, it can be easily attached, the structure of the movable wall is simplified, and the volume occupied by the movable wall can be reduced. Further, by adjusting the material of the cushioning material 206 accommodated in the gas chamber 204 and the thickness of the cylindrical shape in the radial direction, the spring constant indicating the hardness can be arbitrarily determined. Therefore, it is possible to deal with various pressures that vary depending on the position where the pipe is attached.

When the diaphragm 202 as described above is used, the buffer material 206 does not necessarily have to be used, and the use of the buffer material 206 may be omitted.

Alternatively, a coil spring or the like may be used.

(Third Embodiment) FIG. 4 is a sectional view of a water hammer preventer according to the third embodiment.

In the water hammer preventer 300 shown in FIG. 4, a cylinder 301 as an absorption case is connected to the casing 101 of the jet pump 106, and a piston 302 as a movable wall is slidably provided in the cylinder 301. . Due to this piston 302, the inside of the cylinder 301 is a liquid chamber 303.
And a gas chamber 304, and the liquid chamber 303 communicates with the low pressure chamber 111 of the jet pump 106. An O-ring 305 is attached to the piston 302 to seal the liquid chamber 303 so that water does not leak toward the gas chamber 304.

A projecting rod 306 projecting upward is formed at the center of the piston 302 on the gas chamber 304 side. The height of the protruding rod 306 is higher than that of any other portion of the piston 302, and a rubber stopper 307 is attached to the upper portion thereof.

The upper end of the cylinder 301 is the upper cap 20.
The upper cap 205 is closed by an orifice 308 that connects the gas chamber 304 to the outside.

The rubber stopper 307 contacts the lower end of the orifice 308 to close the lower end of the orifice 308 when the piston 302 moves up to a predetermined position.

In the case of the above structure, when the water is supplied through the piping system, the pressure in the low pressure chamber 111 decreases and the pressure in the liquid chamber 303 also decreases, so that the piston 302 is pulled and the volume of the gas chamber 304 increases. . Since the gas chamber 304 communicates with the outside air through the orifice 308, the outside air is sucked into the gas chamber 304 through the orifice 308. Therefore, the volume of the gas chamber 304 increases during the supply of water, and the inside of the gas chamber 304 is maintained at a pressure equal to the atmospheric pressure.

When a water hammer occurs, the air in the low pressure chamber 111 rises, and this pressure is transmitted to the liquid chamber 303 and pushes up the piston 302. Therefore, the air in the gas chamber 304 is compressed. The compressed air is discharged to the outside air through the orifice 308. At this time, since the volume of the gas chamber 304 is sufficiently large and the escape of air is regulated by the flow rate limiting action of the orifice 308, a large amount of air can absorb the pressure applied to the piston 302.

In the case of the above embodiment, since the piston 302 is used as the movable wall, the degree of freedom for moving inside the cylinder 301 is increased, and therefore a large volume for absorbing pressure due to water hammer should be secured. Is possible.

Further, since the orifice 308 communicating with the gas chamber 304 is provided, air can be freely replenished from the outside through the orifice 308 even when the piston 302 descends due to the pressure drop in the liquid chamber 303.
The gas chamber 304 does not become negative pressure. Further, by changing the size of the diameter of the orifice 308, the gas chamber 3
The amount of air released from 04 to the outside can be adjusted, and the moving speed of the piston 302 when a water hammer occurs can be adjusted. For example, when the diameter is formed small, the moving speed of the piston 302 can be reduced,
Further, when the diameter is formed large, the moving speed of the piston 302 can be increased. Therefore, by setting the size of the diameter, the piston 3 can be adjusted according to the size of the water hammer.
02 behavior can be adjusted.

The rubber stopper 307 formed on the projecting rod 306 of the piston 302 hits the lower end of the orifice 308 when the piston 302 moves up to a predetermined position to prevent the piston 302 from further moving up and close the orifice 308. . Therefore, the following effects are achieved. That is, when water is not supplied in the water supply system, the pump action of the jet pump 106 does not occur. At this time, a head pressure due to the difference in height from the high tank 13 acts on the branch pipe 15, and this head pressure acts on the piston 302. If the stopper 307 is not provided here, the piston 302 is pushed up until it abuts the upper cap 205, and air does not exist in the gas chamber 304.

On the other hand, since the rubber stopper 307 is provided, the rubber stopper 307 contacts the lower end of the orifice 308 to regulate the upward movement position of the piston 302. Therefore, a space is secured above the piston 302, that is, air can be kept in the gas chamber 304. When the water supply starts, the piston 302 is pulled down by the pump action of the jet pump 106, so that the gas chamber 304
The volume of the air is increased, and outside air can be sucked in through the orifice 308.

Further, since the rubber stopper 307 closes the orifice 308, the water in the liquid chamber 303 is prevented from leaking from the orifice 308 through the gas chamber 304 when the sealing function is lost due to damage of the O-ring 305 or the like. can do.

When the piston 302 as described above is used, the orifice 308 is not necessarily used, and the orifice 308 may be omitted.

(Fourth Embodiment) FIG. 5 is a sectional view of a water hammer preventer according to a fourth embodiment.

The water hammer preventer 400 shown in FIG. 5 has a piston 302 that is different from that of the third embodiment shown in FIG.
The difference lies in that the protruding rod 306 and the rubber stopper 307 are eliminated and the check valve 401 is provided in the upper cap 205.

With this structure, when the piston 302 is pulled down during the water supply and the pressure in the gas chamber 304 drops, the check valve 401 opens the orifice 308 to allow the intake of air from the outside. Since the inside of the chamber 304 can be maintained at the same level as the atmospheric pressure, the gas chamber 304 does not become a negative pressure. When a water hammer occurs, the check valve 401 closes the orifice 308 so that the air in the gas chamber 304 is not released to the outside, and the gas chamber 304 for absorbing the water hammer is generated.
The volume can be easily secured, and the water hammer can be absorbed by the air inside the gas chamber.

Further, the check valve 401 regulates the upward movement of the piston 302 even if the water head pressure is applied to the piston 302 when the water supply is stopped, like the operation of the rubber stopper 307 of the third embodiment. However, the air in the gas chamber 304 is prevented from running out.

(Fifth Embodiment) FIG. 6 is a sectional view of a water hammer preventer according to a fifth embodiment.

The water hammer preventer 500 shown in FIG. 6 is different from the third embodiment shown in FIG.
1 has a structure in which a bellows 501 is provided instead of the piston 302, and the other structures are common.

The bellows 501 may be made of rubber or metal, and is formed in a bellows shape which is expandable and contractible and has elasticity. An upper end of the bellows 501 is attached to the upper cap 205, and an orifice 308 is attached to the upper cap 205 so that outside air can freely flow in and out.

According to the above construction, the water hammer can be absorbed by the elasticity of the bellows 501, and the spring constant can be variously changed.

Further, due to the pressure drop in the liquid chamber 303, air can be freely replenished through the orifice 308 when the bellows 501 expands, and the gas chamber 304 does not become negative pressure. Therefore, the gas chamber 30 for absorbing the water hammer
The volume of 4 can be easily secured.

Also in this case, the amount of air discharged from the gas chamber 304 to the outside can be adjusted by changing the diameter of the orifice 308. Therefore, the bellows 501 contracts when a water hammer occurs depending on the size of the diameter. The amount can be adjusted.

The bellows 501 can have elasticity to such an extent that it is not crushed even if a head pressure is applied when the water supply is stopped.

In the above description, the first to fifth embodiments have been described, but in addition to these embodiments, various combinations of movable walls, orifices, check valves, internal elastic members, etc. can be selected. Therefore, various modifications can be made to the embodiments other than those described above within the scope of the claims.

[0069]

As described above, according to the invention of claim 1, since the air bag is provided in the low pressure chamber of the jet pump, the gas in the air bag does not dissolve in the water supply, and the air is supplied during the water supply. The bag is not crushed, so that a large volume for absorbing pressure when a water hammer occurs can be secured.

Moreover, since the air bag is provided directly in the low pressure chamber,
It is possible to provide a water hammer preventer having a compact overall shape.

According to the second aspect of the present invention, since the movable wall is provided in the cylinder chamber, it is possible to prevent the gas from dissolving in the water supply and being reduced, and to secure a large volume of the gas chamber. Therefore, it is possible to replenish the gas regularly,
It is not necessary to provide a gas chamber having a large volume in advance, maintenance is easy, and a small water hammer preventer can be provided.

According to the invention of claim 3, since the air supply means for automatically supplying air to the gas chamber is provided, it is possible to provide a water hammer preventer which can save the labor of supplying air and can be easily handled. it can.

According to the invention of claim 4, the behavior of the movable wall when a water hammer occurs can be adjusted by the size of the diameter of the orifice, and a water hammer preventer according to the magnitude of the water hammer is provided. You can

According to the invention of claim 5, since the check valve is provided in the orifice, when the pressure of the gas chamber is lowered, air is sucked from the outside, and when the water hammer occurs, the check valve is closed to close the gas chamber. It is possible to provide a water hammer preventer which does not discharge the gas of the above and can easily secure the volume of the gas chamber for absorbing the water hammer. Further, air can be secured in the gas chamber even when the water supply is stopped.

According to the sixth aspect of the invention, since the elastic member is provided in the gas chamber, the volume of the gas chamber for absorbing the water hammer can be secured, and the spring constant of the elastic member can be set arbitrarily. Therefore, it is possible to provide a water hammer preventer having an absorption capacity according to the size of the water hammer.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a water supply system to which a water hammer preventer of the present invention is attached.

FIG. 2 is a sectional view of a water hammer preventer according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a water hammer preventer according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a water hammer preventer according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a water hammer preventer according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a water hammer preventer according to a fifth embodiment of the present invention.

[Explanation of symbols]

 101 ... Casing 102 ... Body 103 ... Cap 104 ... Inflow port 105 ... Outflow port 106 ... Jet pump 107 ... Introduction nozzle 108 ... Spreading nozzle 109 ... Small-diameter throttle part 110 ... Communication part 111 ... Low pressure chamber 112 ... Air bag 201 ... Absorption case 202 ... Diaphragm 203, 303 ... Liquid chamber 204, 304 ... Gas chamber 206 ... Buffer material 301 ... Cylinder 302 ... Piston 307 ... Rubber stopper 308 ... Orifice 401 ... Check valve 501 ... Bellows

Claims (6)

[Claims] 1. An inflow port and an outflow port, wherein a small-diameter throttle portion is formed between the inflow port and the outflow port, and
A jet pump having a low-pressure chamber communicating with the small-diameter throttle portion and having a low pressure due to the liquid being sucked into the small-diameter throttle portion when the liquid flows from the inlet to the outlet.
A water hammer prevention device, comprising: a gas bag installed in the low pressure chamber, having a gas chamber formed therein, and elastically deformable according to a change in pressure of the low pressure chamber. 2. An inflow port and an outflow port, wherein a small-diameter throttle portion is formed between the inflow port and the outflow port, and
A jet pump having a low-pressure chamber communicating with the small-diameter throttle portion and having a low pressure due to the liquid being sucked into the small-diameter throttle portion when the liquid flows from the inlet to the outlet.
An absorption case connected to the low-pressure chamber; a movable wall that divides the absorption case into a liquid chamber and a gas chamber connected to the low-pressure chamber and that moves according to a change in pressure of the liquid chamber. Water hammer prevention device. 3. The gas chamber contains air, and air replenishing means is provided to automatically replenish the gas chamber with air when the pressure in the gas chamber becomes lower than atmospheric pressure. The water hammer preventer according to claim 2. 4. The water hammer preventer according to claim 3, wherein the air supply means is an orifice. 5. The water hammer according to claim 3 or 4, wherein the air supply means is provided with a check valve for preventing the air in the gas chamber from flowing out. Preventer. 6. The water hammer preventer according to claim 2, wherein an elastic member for pressing the movable wall is provided in the gas chamber.