CN116608305A - Valve assembly and water heater - Google Patents

Abstract

The invention provides a valve assembly and a water heater. The valve assembly comprises a shell, wherein the two ends of the shell are respectively provided with a fluid inlet and a fluid outlet; the first valve core and the second valve core are arranged in the shell, the second valve core is limited at a designated position through the limiting part, and when the pressure born by the valve assembly reaches a preset pressure, the first valve core pushes the limiting part to separate from the second valve core, so that the second valve core seals the fluid outlet. Therefore, the part is prevented from cracking, and water supply can be timely interrupted after the part at the water outlet end is frozen and cracked.

Description

Valve assembly and water heater

Technical Field

The invention relates to the field of valves, in particular to a valve assembly and a water heater.

Background

When the household water heater supplies water, the problem that the water flow in the pipeline is unstable is commonly existed. The water flow or water pressure fluctuation generated under the problem is light, so that the water outlet of the water heater is suddenly cold and hot, and the heavy water pressure fluctuation causes the part cracking caused by the overlarge water pressure. In addition to the risk of cracking of the parts, frost cracking of the parts at the water outlet end may occur due to excessively low ambient temperatures. The water heater in the prior art can continue to supply water according to the operation of a user without regard to the leakage risk of the frost crack of the parts at the water outlet end, and lacks a protection mechanism capable of timely interrupting water supply under the condition. Therefore, there is a need in the market for a protection mechanism that can prevent part cracking and that can interrupt the water supply in time after the part at the water outlet end has frozen cracking.

Disclosure of Invention

The invention aims to solve the technical problems that in order to prevent parts from cracking and timely interrupt water supply after the parts at the water outlet end are cracked by freezing, and provides a valve assembly and a water heater.

The invention solves the technical problems by the following technical scheme:

a valve assembly, comprising:

the two ends of the shell are respectively provided with a fluid inlet and a fluid outlet;

the first valve core and the second valve core are arranged in the shell, the second valve core is limited at a designated position through the limiting part, and when the pressure born by the valve assembly reaches a preset pressure, the first valve core pushes the limiting part to separate from the second valve core, so that the second valve core seals the fluid outlet.

In this embodiment, the fluid inlet of the housing is the inlet through which fluid initially passes into the valve assembly and the fluid outlet of the housing is the outlet through which fluid eventually passes out of the valve assembly. When fluid enters the valve assembly from the fluid inlet, the pressure of the fluid acts on the end face of the first valve core, which is close to the fluid inlet, so that the first valve core is pushed to move towards the fluid outlet; when the pressure reaches a preset pressure, namely the maximum value which can be born by the water supply system, the first valve core moves towards the fluid outlet further and pushes the limiting part to release the second valve core from the limitation of the limiting part, and then the end face, close to the fluid inlet, of the second valve core is acted by the pressure of the fluid to enable the second valve core to move towards the fluid outlet, and finally the second valve core closes the fluid outlet to interrupt the water supply of the valve assembly. In this way, when the water flow rate or water pressure flowing into the valve assembly is abnormally increased suddenly, the valve assembly pushes the limiting part through the first valve core to release the second valve core, the second valve core is used for closing the fluid outlet and realizing water supply interruption, and further, part cracking caused by excessive water pressure is prevented. Similarly, when the part at the water outlet end is frozen and cracked due to the too low environmental temperature, the water pressure at the water outlet end is suddenly reduced, so that the water pressure when the part enters the valve assembly is far greater than the water pressure at the water outlet end, and the pressure difference can also enable the first valve core to push the limiting part to release the second valve core, so that the second valve core is utilized to seal the fluid outlet and interrupt water supply.

Preferably, the second valve core surrounds the outside of the first valve core, and when the second valve core is at the designated position, the limiting part penetrates from the outer wall of the housing to the inner wall of the second valve core and protrudes from the inner wall of the second valve core.

In this scheme, spacing portion wears to establish to the inner wall of second case and from the inner wall of second case from the outer wall of casing to make spacingly to the second case that is in the casing inside through setting up at the outside spacing portion of casing, realized a outside-in spacing mode. In this way, an operator can directly operate and adjust the limit relationship between the limit portion and the second valve spool from the outside of the valve assembly, saving the need to disassemble the valve assembly to achieve operation and adjustment.

Preferably, one end of the first valve core facing the fluid inlet is attached to the inner wall of the second valve core, so that the end of the first valve core facing the fluid inlet moves along the inner wall of the second valve core to push the limiting part to be separated from the second valve core.

In this scheme, through laminating on the inner wall of second case with the one end towards the fluid entry on the first case, utilize above-mentioned end to promote the spacing portion that protrudes on the inner wall of second case, the cooperation relationship between the two is simple convenient, easily realizes utilizing first case to promote spacing portion and come the release to the second case.

Preferably, the second valve element has a baffle at an end thereof facing the fluid outlet, the baffle extending between an inner wall of the housing and an outer wall of the first valve element, the second valve element closing the fluid outlet by the baffle.

In this scheme, the baffle extends between the inner wall of casing and the outer wall of first case to when utilizing the second case to seal the fluid outlet, the baffle can fully and completely seal the whole fluid outlet, has improved the closure effect more.

Preferably, an elastic member accommodating cavity is formed between one end of the first valve core facing the fluid inlet and the baffle along the central axis of the shell, a first elastic member is arranged in the elastic member accommodating cavity, and the first elastic member provides force for enabling the second valve core to move towards the fluid outlet.

In the scheme, the first elastic piece is arranged in the elastic piece accommodating cavity, so that in the first aspect, water is normally introduced into the valve assembly before the water pressure reaches the maximum value which can be borne by the water supply system, the second valve core is limited at a designated position, the elastic force provided by the first elastic piece enables the first valve core to actively deflect towards the direction away from the limiting part, and the situation that the second valve core is released due to the fact that the first valve core accidentally contacts the limiting part is avoided; when the water pressure reaches the maximum value, the first valve core overcomes the elasticity of the first elastic piece and pushes the limiting part to release the second valve core, and the second valve core is quickly pushed to the fluid outlet by utilizing the elasticity of the first elastic piece to timely interrupt water supply. When the water pressure reaches the maximum value and returns to normal again, an operator can push the second valve core to be separated from the position for closing the fluid outlet by using the tool, and at the moment, the elastic force of the first elastic piece enables the second valve core to drive the first valve core to return to the initial position together, so that the operation steps in the resetting process are saved.

Preferably, a clamping hook is arranged at one end of the limiting part, which protrudes out of the inner wall of the second valve core, and the second valve core is hooked at a designated position through the clamping hook;

and/or the position on the outer wall of the shell, penetrated by the limiting part, is provided with a limiting accommodating cavity, a second elastic piece is arranged in the limiting accommodating cavity, and the second elastic piece provides a force for enabling the limiting part to deviate away from the second valve core.

In this scheme, the second case is hung in appointed position through the pothook, and the cooperation between pothook and the second case is simple convenient and easy realization. Meanwhile, due to the arrangement of the hooks, the limiting stability and reliability between the limiting part and the second valve core are guaranteed, and the accidental release of the limiting part to the second valve core is prevented. In this scheme, the second elastic component provides the power that makes spacing portion keep away from second case skew to when first case promotes spacing portion release second case, can withdraw from the second case fast with spacing portion, release speed is faster. By providing the spring receiving cavity, unnecessary movement or wobble of the spacing portion and the second spring on the valve assembly is prevented, such that the second spring is able to more effectively provide a force biasing the spacing portion away from the second spool.

Preferably, the valve assembly further comprises a throttle portion located at the fluid outlet and extending along the central axis of the housing towards the interior of the housing.

In the scheme, the valve assembly changes the size of a through-flow space formed by the first valve core and the surface of the throttling part through the change of the position of the first valve core, so that the flow speed of fluid passing through the valve assembly is regulated, the total through-flow is kept unchanged, and the steady flow effect is realized.

Preferably, when the second valve core closes the fluid outlet, the second valve core abuts against the outer edge of the base of the throttling part.

In the scheme, the inner wall of the second valve core is abutted against the base part of the throttling part, so that the inner wall of the valve core and the base part of the throttling part form secondary sealing when the second valve core seals the fluid outlet, and a better sealing effect on fluid is realized.

Preferably, the fluid inlet is provided with a first stop extending towards the interior of the housing;

and/or a second stop extending towards the interior of the housing is provided at the fluid outlet.

In this scheme, first backstop portion and second backstop portion have played the anticreep effect to first case and second case in the casing to avoided the valve assembly to disintegrate in the use by accident.

A water heater comprising a valve assembly as claimed in any one of the preceding claims.

In this scheme, the water heater through being provided with foretell valve assembly, can prevent that the part from rising to split and can in time interrupt the water supply after the part of water outlet takes place to freeze to split.

On the basis of conforming to the common knowledge in the field, the above preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

The invention has the positive progress effects that: the valve component and the water heater can prevent parts from cracking, and can interrupt water supply in time after the parts at the water outlet end are cracked by freezing, so that the invention has remarkable progress.

Drawings

FIG. 1 is a schematic perspective view of a valve assembly according to an embodiment of the present invention;

FIG. 2 is a schematic illustration (one) of the operation of the valve assembly according to the embodiment of the present invention;

FIG. 3 is a schematic view of the valve assembly according to the embodiment of the present invention;

FIG. 4 is a schematic view of the valve assembly according to an embodiment of the present invention;

FIG. 5 is a schematic perspective view of a first valve element of a valve assembly according to an embodiment of the present invention;

fig. 6 is a schematic perspective view of a second valve core of the valve assembly according to the embodiment of the present invention.

Reference numerals illustrate:

valve assembly 1000

Housing 10

Fluid inlet 11

Fluid outlet 12

Throttle part 13

First valve element 21

Second spool 22

Baffle 30

Limit part 40

Hook 41

Spring receiving chamber 50

First elastic member 51

Spacing accommodation chamber 60

Second elastic member 61

First stop portion 71

Second stop portion 72

Detailed Description

The invention is further illustrated by means of examples which follow, without thereby restricting the scope of the invention thereto.

As shown in fig. 1-4, a valve assembly 1000 includes:

a housing 10, both ends of the housing 10 being provided with a fluid inlet 11 and a fluid outlet 12, respectively;

the first valve core 21 and the second valve core 22, the first valve core 21 and the second valve core 22 are disposed inside the housing 10, the second valve core 22 is limited at a designated position by the limiting portion 40, and when the pressure applied to the valve assembly 1000 reaches a predetermined pressure, the first valve core 21 pushes the limiting portion 40 to disengage from the second valve core 22, so that the second valve core 22 closes the fluid outlet 12.

In particular implementations, the fluid inlet 11 of the housing 10 is the inlet through which fluid initially passes into the valve assembly 1000, and the fluid outlet 12 of the housing 10 is the outlet through which fluid eventually passes out of the valve assembly 1000. When fluid enters the valve assembly 1000 from the fluid inlet 11, the pressure of the fluid acts on the end face of the first valve spool 21 adjacent to the fluid inlet 11, thereby pushing the first valve spool 21 to move toward the fluid outlet 12; when the pressure reaches a predetermined pressure, i.e. the maximum value that can be borne by the water supply system, the first valve element 21 moves further towards the fluid outlet 12 and pushes the limiting part 40 to release the second valve element 22 from the limitation of the limiting part 40, and then the end surface of the second valve element 22, which is close to the fluid inlet 11, is also subjected to the pressure of the fluid, so that the second valve element 22 moves towards the fluid outlet 12, and the second valve element 22 finally closes the fluid outlet 12 to interrupt the water supply of the valve assembly 1000. In this way, when the water flow rate or water pressure flowing into the valve assembly 1000 is abnormally increased suddenly, the valve assembly 1000 pushes the limiting part 40 through the first valve core 21 to release the second valve core 22, the fluid outlet 12 is closed by the second valve core 22, and the water supply is interrupted, so that the part crack caused by the excessive water pressure is prevented. Similarly, when the parts at the water outlet end are frozen and cracked due to too low environmental temperature, the water pressure at the water outlet end is suddenly reduced, so that the water pressure when the valve assembly 1000 is introduced is far greater than the water pressure at the water outlet end, and the pressure difference also causes the first valve core 21 to push the limiting part 40 to release the second valve core 22, so that the second valve core 22 is utilized to close the fluid outlet 12 and interrupt water supply. The valve assembly 1000 in the present embodiment is a valve assembly 1000 unit based on a set of the housing 10, the first valve core 21 and the second valve core 22, and in practice, a person skilled in the art may use a plurality of the valve assembly 1000 units according to actual needs, so as to meet the actual needs in the case of multiple pipes or large-area laying, which is not limited in the present embodiment. In this embodiment, the housing 10, the first valve core 21 and the second valve core 22 are all straight cylinders, and as an alternative embodiment, the housing 10, the first valve core 21 and the second valve core 22 may all have a certain arc, so that a state similar to a "C" shape is presented, and under the premise of not affecting the normal operation of the valve assembly 1000, a person skilled in the art can choose whether to set the arc and the specific size of the arc according to the actual requirement, which is not limited in this embodiment. On the other hand, in the present embodiment, the outermost wall surface of the second valve core 22 is attached to the inner wall of the housing 10, so that a good sealing effect is achieved between the housing 10 and the second valve core 22, and further, the pushing effect can be more fully and effectively exerted when the water pressure of the fluid acts on the end surface of the second valve core 22, which is close to the fluid inlet 11. Alternatively, a gap may be formed between the wall surface of the outermost edge of the second valve core 22 and the inner wall of the housing 10, and the hydraulic pressure of the fluid may act on the end surface of the second valve core 22 near the fluid inlet 11 to push the second valve core 22 toward the fluid outlet 12, so that a coating or film that is commonly used in the art and can perform sealing and lubrication functions, such as graphite or vaseline, may be used between the gaps, which is not limited in this embodiment. Further, the fluid channel in the valve assembly 1000 in this embodiment is a flat and smooth surface, however, those skilled in the art may also use a flow stabilizing structure commonly used in the art, such as a protrusion for preventing turbulence or a guide piece for guiding fluid, in the fluid channel according to actual needs, and this embodiment is not limited thereto.

As shown in fig. 2 to 4 and fig. 6, the second spool 22 is disposed around the outside of the first spool 21, and when the second spool 22 is at the specified position, the stopper 40 is penetrated from the outer wall of the housing 10 to the inner wall of the second spool 22 and protrudes from the inner wall of the second spool 22.

In the specific implementation, the limiting part 40 penetrates from the outer wall of the housing 10 to the inner wall of the second valve core 22 and protrudes from the inner wall of the second valve core 22, so that the limiting part 40 arranged outside the housing 10 limits the second valve core 22 in the housing 10, and an outside-in limiting mode is realized. In this manner, an operator can directly operate and adjust the spacing relationship between the spacing portion 40 and the second spool 22 from the exterior of the valve assembly 1000, saving the need to disassemble the valve assembly 1000 to effect the operation and adjustment.

As shown in fig. 2 to 4 and 5, the end of the first valve core 21 facing the fluid inlet 11 is attached to the inner wall of the second valve core 22, so that the end of the first valve core 21 facing the fluid inlet 11 moves along the inner wall of the second valve core 22 to push the limiting portion 40 to be separated from the second valve core 22.

In a specific implementation, by attaching the end of the first valve core 21 facing the fluid inlet 11 to the inner wall of the second valve core 22, the end is used to push the limiting portion 40 protruding from the inner wall of the second valve core 22, and the matching relationship between the two is simple and convenient, so that the first valve core 21 is used to push the limiting portion 40 to release the second valve core 22 easily. As an alternative embodiment, a gap may be formed between the end of the first valve core 21 facing the fluid inlet 11 and the inner wall of the second valve core 22, and a coating or film that is commonly used in the art and can perform sealing and lubrication functions, such as graphite or vaseline, may be used between the gaps by those skilled in the art without obstructing the first valve core 21 from pushing the limiting portion 40, which is not limited in this embodiment.

As shown in fig. 2-4, the second spool 22 has a baffle 30 at an end thereof facing the fluid outlet 12, the baffle 30 extending between the inner wall of the housing 10 and the outer wall of the first spool 21, the second spool 22 closing the fluid outlet 12 by the baffle 30.

In particular, the baffle 30 extends between the inner wall of the housing 10 and the outer wall of the first valve element 21, so that when the fluid outlet 12 is closed by the second valve element 22, the baffle 30 can fully and completely seal the entire fluid outlet 12, and the sealing effect is further improved. The baffle 30 in the present embodiment is provided so as to be able to smoothly and completely fit the entire end surface of the housing 10 on which the fluid outlet 12 is provided from the inside of the housing 10, thereby ensuring reliability at the time of closing. As an alternative embodiment, the specific shape of the baffle 30 may be set to match only the shape of the fluid outlet 12, or provided with an engagement protrusion capable of protruding from the fluid outlet 12 toward the outside of the housing 10 in the closed state, thereby achieving a better closing effect, which is not limited by the present embodiment.

As shown in fig. 2 to 4, an elastic member receiving chamber 50 is formed between an end of the first spool 21 facing the fluid inlet 11 and the baffle 30 along the central axis of the housing 10, and a first elastic member 51 is provided in the elastic member receiving chamber 50, the first elastic member 51 providing a force to move the second spool 22 toward the fluid outlet 12.

In particular implementation, the first elastic member 51 is disposed in the elastic member accommodating cavity 50, so that, in the first aspect, before the water pressure reaches the maximum value that can be borne by the water supply system, the valve assembly 1000 is normally opened, the second valve core 22 is limited at a designated position, the elastic force provided by the first elastic member 51 enables the first valve core 21 to be actively biased towards a direction away from the limiting portion 40, and the first valve core 21 is prevented from accidentally contacting the limiting portion 40 to cause the second valve core 22 to be released; when the water pressure reaches the maximum value, the first valve core 21 overcomes the elastic force of the first elastic member 51 and pushes the limiting part 40 to release the second valve core 22, and the second valve core 22 is rapidly pushed to the fluid outlet 12 by the elastic force of the first elastic member 51, so that the water supply is timely interrupted. When the water pressure reaches the maximum value and returns to normal again, the operator can push the second valve core 22 by using the tool to separate from the position of the closed fluid outlet 12, and at this time, the elastic force of the first elastic member 51 makes the second valve core 22 drive the first valve core 21 to return to the initial position together, so that the operation steps during the return are saved. In addition, the first elastic member 51 in the present embodiment is a compression spring, and the compression spring provides a preloaded elastic force. Alternatively, a spring or elastomeric ring, as is commonly known in the art, may be employed by those skilled in the art to provide the force to move the second valve spool 22 toward the fluid outlet 12, as this example is not limiting. As a further embodiment, a step or a slot for fixing the first elastic member 51 may be provided in the elastic member receiving chamber 50 by a person skilled in the art, so as to prevent the first elastic member 51 from moving or swaying in the elastic member receiving chamber 50, which is not limited in this embodiment.

As shown in fig. 2-4, a hook 41 is provided at one end of the limiting portion 40 protruding from the inner wall of the second valve core 22, and the second valve core 22 is hooked at a designated position by the hook 41;

and, a position on the outer wall of the housing 10 penetrated by the limiting part 40 is provided with a limiting accommodating cavity 60, a second elastic member 61 is arranged in the limiting accommodating cavity 60, and the second elastic member 61 provides a force for biasing the limiting part 40 away from the second spool 22.

In specific implementation, the second valve core 22 is hooked at a designated position through the hook 41, and the cooperation between the hook and the second valve core 22 is simple, convenient and easy to realize. Meanwhile, the arrangement of the hooks also ensures the stable and reliable limiting between the limiting part 40 and the second valve core 22, and prevents the accidental release of the limiting part 40 to the second valve core 22. In this embodiment, the second elastic member 61 provides a force for biasing the limiting portion 40 away from the second spool 22, so that when the first spool 21 pushes the limiting portion 40 to release the second spool 22, the limiting portion 40 can be quickly withdrawn from the second spool 22, and the release speed is faster. By providing the elastic member receiving chamber 50, unnecessary movement or shake of the stopper 40 and the second elastic member 61 on the valve assembly 1000 is prevented, so that the second elastic member 61 can more effectively provide a force to bias the stopper 40 away from the second spool 22. Meanwhile, the limiting portion 40 in the present embodiment is disposed to partially protrude out of the limiting accommodating cavity 60, so that an operator can manually adjust the limiting portion 40. The second elastic member 61 in the present embodiment is a compression spring, and the compression spring provides a preloaded elastic force. As an alternative embodiment, a person skilled in the art may also use an elastic member such as a tension spring or an elastic rubber ring, which is commonly known in the art, to provide the force for biasing the retainer 40 away from the second spool 22, which is not limited in this embodiment. In addition, the valve assembly 1000 in the present embodiment uses two sets of the stopper units constituted by the stopper accommodation chamber 60, the stopper portion 40, and the second elastic member 61, which are disposed on the same axis perpendicular to the central axis of the housing 10, thereby bidirectionally restricting the second spool 22 at a specified position. As an alternative embodiment, other numbers of limiting units than two sets may be used, for example, only one set or three sets, four sets of limiting units, etc., which is not limited in this embodiment.

As shown in fig. 2-4, the valve assembly 1000 further includes a throttle portion 13, the throttle portion 13 being located at the fluid outlet 12 and extending along the central axis of the housing 10 toward the interior of the housing 10.

In a specific implementation, the valve assembly 1000 changes the size of the through-flow space formed by the first valve core 21 and the surface of the throttling part 13 through the change of the position of the first valve core 21, so as to adjust the flow rate of the fluid passing through the valve assembly 1000, so that the total through-flow is kept unchanged, and the steady flow effect is realized. Further, the throttle 13 in the present embodiment cooperates with the first valve core 21 and the first elastic member 51, and the first valve core 21 can perform autonomous adjustment and realize reciprocating movement by elastic force provided by the first elasticity, so as to make specific adjustment of the through-flow space according to the change of the water pressure.

As shown in fig. 4, when the second valve element 22 closes the fluid outlet 12, the second valve element 22 abuts against the outer edge of the base portion of the throttle portion 13.

In specific implementation, the inner wall of the second valve core 22 abuts against the base of the throttling part 13, so that the inner wall of the valve core and the base of the throttling part 13 form secondary sealing while the second valve core 22 seals the fluid outlet 12, and a better sealing effect on fluid is achieved.

As shown in fig. 2-4, a first stop 71 is provided at the fluid inlet 11 extending towards the interior of the housing 10;

and, a second stopper 72 extending toward the inside of the housing 10 is provided at the fluid outlet 12.

In particular implementations, the first stop 71 and the second stop 72 provide an anti-disengagement effect on the first spool 21 and the second spool 22 within the housing 10, thereby avoiding accidental disassembly of the valve assembly 1000 during use. In the present embodiment, the second stop portion 72 is also a connection portion for connecting the throttle portion 13 to the housing 10, and the second stop portion 72 has a bar-shaped barrier structure, so that the fluid outlet 12 is divided into a plurality of openings. In the present embodiment, the first stop portion 71 is an annular structure, and the annular structure is formed by turning the housing 10 directly toward the inside of the housing 10. However, in the specific implementation, those skilled in the art may also use a conventional stop structure in the art to make modifications or substitutions on the first stop portion 71 and the second stop portion 72 according to actual needs, for example, using a grid structure stop portion, which is not limited in this embodiment.

Not shown in the figures, a water heater includes a valve assembly 1000 of any of the above.

In a specific implementation, the water heater can prevent the parts from cracking by the valve assembly 1000, and can interrupt water supply in time after the parts at the water outlet end are frozen and cracked.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.

Claims (10)

1. A valve assembly, the valve assembly comprising:

the two ends of the shell are respectively provided with a fluid inlet and a fluid outlet;

the first valve core and the second valve core are arranged in the shell, the second valve core is limited at a designated position through the limiting part, and when the pressure born by the valve assembly reaches a preset pressure, the first valve core pushes the limiting part to separate from the second valve core, so that the second valve core seals the fluid outlet.

2. The valve assembly of claim 1, wherein the second valve spool is disposed about an exterior of the first valve spool, and wherein the limit portion extends from an exterior wall of the housing to an interior wall of the second valve spool and protrudes from the interior wall of the second valve spool when the second valve spool is in the designated position.

3. The valve assembly of claim 2, wherein an end of the first valve spool facing the fluid inlet is attached to an inner wall of the second valve spool such that an end of the first valve spool facing the fluid inlet moves along the inner wall of the second valve spool to urge the retainer portion away from the second valve spool.

4. The valve assembly of claim 3, wherein the second valve spool has a baffle at an end thereof facing the fluid outlet, the baffle extending between an inner wall of the housing and an outer wall of the first valve spool, the second valve spool closing the fluid outlet by the baffle.

5. The valve assembly of claim 4, wherein a spring receiving chamber is formed between an end of the first valve spool facing the fluid inlet and the baffle along a central axis of the housing, a first spring being disposed in the spring receiving chamber, the first spring providing a force to move the second valve spool toward the fluid outlet.

6. The valve assembly according to claim 2, wherein a hook is provided on one end of the limit portion protruding from the inner wall of the second valve element, and the second valve element is hooked at a designated position by the hook;

and/or a limiting accommodating cavity is formed in the outer wall of the shell at a position penetrated by the limiting part, a second elastic piece is arranged in the limiting accommodating cavity, and the second elastic piece provides a force for enabling the limiting part to deviate away from the second valve core.

7. The valve assembly of claim 1, further comprising a throttling portion located at the fluid outlet and extending along a central axis of the housing toward the housing interior.

8. The valve assembly of claim 7, wherein the second valve spool abuts against the outer edge of the base of the restriction when the second valve spool closes the fluid outlet.

9. The valve assembly of any one of claims 1-8, wherein the fluid inlet is provided with a first stop extending toward the interior of the housing;

and/or a second stop extending towards the interior of the housing is provided at the fluid outlet.

10. A water heater comprising a valve assembly as claimed in any one of claims 1 to 9.