GB2594320A

GB2594320A - Small water heater

Info

Publication number: GB2594320A
Application number: GB2006009.1A
Authority: GB
Inventors: Lin Yongjian; Yang Yingna; Su Xiaoxiang
Original assignee: Xiamen Synbop Tech Co Ltd
Current assignee: Xiamen Synbop Tech Co Ltd
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-10-27
Also published as: GB202006009D0

Abstract

A water heater has an inlet pipe, pressure maintaining valve 2, flow regulating valve, water heating tank and outlet pipe sequentially arranged along a water flow direction. The pressure maintaining valve comprises a body 20 having an upstream and downstream end. The body houses a valve seat 21, a valve core 22 comprising a sleeve 220 having a spring 221 on an inner surface thereof, and a vent member 23. The valve seat abuts an inner wall of the body at the upstream end but is spaced from the inner wall at the downstream end. The valve seat has a water inlet chamber 210 fluidly communicated with the upstream end, and a water through hole 211 fluidly communicated with the water inlet chamber and a side wall of the valve seat that is spaced from the inner wall of the body. The vent member is slidably engaged with the sleeve and includes a vent hole 230 that fluidly communicates an inner cavity of the sleeve with an outside of the body. One end of the sleeve is disposed around the valve seat and is moved by water pressure to adjust the opening size of the water through hole.

Description

SMALL WATER HEATER

FIELD OF THE INVENTION

The invention relates to the technical field of water heaters, and particularly to a small water heater.

BACKGROUND OF THE INVENTION

A water heater refers to a device that heats up cold water into hot water within a certain period of time through various physical principles. According to different principles, water heaters can be divided into electric water heaters, gas water heaters, solar water heaters, magnetic water heaters, air energy water heaters, heating water heaters, etc. A water heating tank of an existing small instantaneous water heater is generally directly communicated with a tap water pipe through a water inlet pipe, the inflowing tap water is immediately heated through the water heating tank and then flows out from a water outlet pipe, and no voltage stabilizing device is arranged. However, the pressure of tap water provided by a water supply system is usually unstable. When the water pressure is too high, the water flow into the water heating tank is fast and the heating time is short, resulting in a low water temperature in the water outlet pipe; and when the water pressure is too low, the water flow into the water heating tank is slow and the heating time is long, resulting in a high water temperature in the water outlet pipe, which easily leads to unstable heating by the water heater and affects the heating effect of the water heater.

SUMMARY OF THE INVENTION

An object of the invention is to provide a small water heater that can adaptively adjust the water flow speed according to the tap water pressure, and stabilize the water pressure provided by external tap water, which can effectively improve the heating stability of the small water heater, so that the temperature of the heated water is relatively stable and the effect is good.

To achieve the above object, the invention employs the following technical solutions.

A small water heater comprises a water inlet pipe, a pressure maintaining valve, a flow regulating valve, a water heating tank and a water outlet pipe which are sequentially arranged along the water flow direction; the pressure maintaining valve comprises a valve body in which a valve seat, a valve core and a vent member are sequentially arranged along the water flow direction; both ends of the valve body are communicated with the water inlet pipe and the flow regulating valve respectively; the valve seat abuts against an inner wall of a water inlet end of the valve body, and a gap is left between the valve seat and an inner wall of a water outlet end of the valve body; the valve seat is internally provided with a water inlet chamber, a water through hole is arranged on a side wall of the water inlet chamber, and water passes sequentially through the water inlet chamber and the water through hole from the water inlet end of the valve body and flows into the water outlet end of the valve body; the valve core comprises a sleeve and a spring sleeved in the sleeve; one end of the sleeve is tightly sleeved outside the valve seat, and the sleeve is driven to move by water pressure to adjust the opening size of the water through hole; one end of the vent member is slidably connected to the sleeve, and the other end of the vent member is fixedly connected to the valve body; the vent member is internally provided with a vent hole; and one end of the vent hole is communicated with an inner cavity of the sleeve, and the other end of the vent hole is communicated with the outside of the valve body.

Preferably, the water inlet pipe comprises a cold water pipe, a socket pipe and a connecting pipe; an upper end of the cold water pipe is communicated with the water inlet end of the valve body, and water inlets are respectively arranged on both sides of a lower end of the cold water pipe; one end of the connecting pipe is fixed on the socket pipe in a penetrating manner, and the other end of the connecting pipe is communicated with a tap water pipe; and the socket pipe is tightly sleeved outside the cold water pipe at the water inlet, and the connecting pipe is communicated with one of the water inlets by rotating the socket pipe.

Preferably, the connecting pipe is provided with an impurity removal mechanism for intercepting impurities in water; the impurity removal mechanism comprises an impurity removal pipe and an impurity removal plug; the impurity removal pipe is fixed on a lower side of the connecting pipe in a penetrating manner; a filter screen is fixed at an upper end of the impurity removal plug; the filter screen is inserted into the connecting pipe from bottom to top; and the impurity removal plug is threadably connected to the impurity removal pipe.

Preferably, a spacing is left between the impurity removal plug and the connecting pipe, and impurities intercepted by the filter screen are precipitated in the impurity removal pipe above the impurity removal plug.

Preferably, the cold water pipe is provided with a first sealing groove outside the water inlet; the first sealing groove is provided with a first sealing ring; one side of the first sealing ring is tightly embedded into the first sealing groove, and the other side thereof abuts against an inner wall of the socket pipe; the impurity removal plug is provided with a second sealing groove; the second sealing groove is provided with a second sealing ring; and one side of the second sealing ring is tightly embedded into the second sealing groove, and the other side thereof abuts against the impurity removal pipe.

Preferably, the cold water pipe is internally provided with a water discharge pipe; an upper end of the water discharge pipe is communicated with the water inlet end of the valve body, and a lower end of the water discharge pipe is communicated with an inner cavity of the cold water pipe; and the cold water pipe is provided with a solenoid valve, and water in the cold water pipe is controlled by the solenoid valve to flow from the water discharge pipe to the pressure maintaining valve Preferably, a third sealing ring is arranged at the position where the valve seat contacts an inner wall of the valve body; the valve seat is provided with a third sealing groove; one side of the third sealing ring is tightly embedded into the third sealing groove, and the other side thereof abuts against the inner wall of the valve body; a fourth sealing ring is arranged at the position where the valve seat contacts an inner wall of the sleeve; the valve seat is provided with a fourth sealing groove; one side of the fourth sealing ring is tightly embedded into the fourth sealing groove, and the other side thereof abuts against the inner wall of the sleeve; a fifth sealing ring is arranged at the position where the sleeve contacts the vent member; the sleeve is provided with a fifth sealing groove; and one side of the fifth sealing ring is tightly embedded into the fifth sealing groove, and the other side thereof abuts against the vent member.

Preferably, a plurality of reinforcing ribs are fixed to the inner wall of the valve body at intervals; and the reinforcing ribs are located outside the sleeve.

Preferably, the water heating tank comprises a water storage tank and a heating element disposed on the water storage tank, and water in the water storage tank is heated by the heating element.

Preferably, the water heating tank is internally provided with a water level pipe for improving the water heating effect; a lower end of the water level pipe is fixed on the water heating tank, and an upper end of the water level pipe is located above a water outlet end of the flow regulating valve; and the water outlet end of the flow regulating valve is communicated with a lower part of the water storage tank, the water outlet pipe is communicated with the lower end of the water level pipe, and the heated water is discharged from the water outlet pipe through the water level By employing the above technical solutions, the invention has the following beneficial effects: 1. in the small water heater of the invention, when water flows into the water outlet end of the valve body from the water through hole, the water accumulated in the water outlet end of the valve body produces a downward reverse pressure on the sleeve, the pressure of the water flowing into the water outlet end of the valve body increases as the water inlet pressure increases, the water pressure pushes the sleeve downward to overcome the resistance of the spring and move to one side of the water inlet end, and gas inside the sleeve is discharged from the vent hole, so that the sleeve gradually reduces the opening size of the water through hole, thus reducing the water flow to the water outlet end of the valve body; and when the water flow to the water outlet end of the valve body is too low, the sleeve moves away from one side of the water inlet end of the valve body under the action of the restoring force of the spring, so that the sleeve gradually increases the opening size of the water through hole, thus increasing the water flow to the water outlet end of the valve body, and finally achieving a dynamic balance between the water outlet pressure and the restoring force of the spring; therefore, the small water heater can adaptively adjust the water flow speed according to the tap water pressure, and stabilize the water pressure provided by external tap water, which can effectively improve the heating stability of the small water heater, so that the temperature of the heated water is relatively stable and the effect is good; 2. in the small water heater of the invention, the connecting pipe can be mounted on the left or right side by rotating the socket pipe according to the actual mounting needs, and has good versatility, which can not only effectively reduce the number of water pipes, but also simplify the water line, thereby providing convenience in use; 3. in the small water heater of the invention, the filter screen on the impurity removal plug can effectively intercept impurities in water, and the threaded connection between the impurity removal plug and the impurity removal pipe facilitates quick disassembly or mounting, and cleaning; and meanwhile, a spacing is left between the impurity removal plug and the connecting pipe, in which the impurities intercepted by the filter screen can be precipitated, thereby avoiding the blockage of the connecting pipe and facilitating the centralized removal of the impurities; 4. in the small water heater of the invention, the first sealing ring and the second sealing ring can improve the sealing effect of the water inlet pipe, and the third sealing ring, the fourth sealing ring and the fifth sealing ring can improve the sealing effect of the pressure maintaining valve, which can effectively improve the working stability of the small water heater; 5. in the small water heater of the invention, the reinforcing ribs can increase the strength of the valve body, effectively reduce the impact of the water pressure on the inner wall of the valve body, and reduce the deformation or even burst of the valve body due to the water pressure; and 6. in the small water heater of the invention, a water inlet of the water level pipe is located above the water outlet end of the flow regulating valve, so that water can be accumulated in the water storage tank from bottom to top, and can be effectively heated by the heating element, then flows into the water inlet of the water level pipe from the upper end and is finally discharged from the water outlet pipe.

BRIEFDESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective structural view of the invention; FIG. 2 is an exploded structural view of the invention; FIG. 3 is a perspective structural view of a water storage tank of the invention; FIG. 4 is a sectional schematic structural view of a water inlet pipe, a pressure maintaining valve and a flow regulating valve of the invention; FIG. 5 is a partially exploded view of a water inlet pipe of the invention; FIG. 6 is a partially enlarged view of a cold water pipe of the invention; FIG. 7 is a schematic structural view of an impurity removal plug and a filter screen of the invention; FIG. 8 is a sectional schematic structural view of the water inlet pipe of the invention; FIG. 9 is an exploded structural view of the pressure maintaining valve of the invention; FIG. 10 is a sectional schematic structural view of the pressure maintaining valve of the invention; FIG. 11 is a sectional schematic structural view of the pressure maintaining valve of the invention when no reinforcing rib is cut; FIG. 12 is a sectional schematic structural view of the pressure maintaining valve of the invention when no valve core is mounted; and FIG. 13 is a sectional schematic structural view of the pressure maintaining valve of the invention when viewed from the top.

The reference numerals in the Figures are expressed as follows: 1. water inlet pipe; 10. cold water pipe; 100. water inlet; 101. first sealing groove; 102. water discharge pipe; 103. solenoid valve; 11. socket pipe; 12. connecting pipe; 13. impurity removal mechanism; 130. impurity removal pipe; 131 impurity removal plug; 1310. second sealing groove; 132. filter screen; 14. first sealing ring; 15. second sealing ring; 2. pressure maintaining valve; 20. valve body; 21. valve seat; 210. water inlet chamber; 211. water through hole; 212. third sealing groove; 213. fourth sealing groove; 22. valve core; 220. sleeve; 2200. fifth sealing groove; 221. spring; 23. vent member; 230. vent hole; 24. third sealing ring; 25. fourth sealing ring; 26. fifth sealing ring; 27. reinforcing rib; 3. flow regulating valve; 4. water heating tank; 40. water storage tank; 41. heating element; 42. water level pipe; 5. water outlet pipe.

DETAILED DESCRIPTION OF THE INVENTION

In order to make the objects, technical solutions and advantages of the invention clearer, the invention will be further described below in detail with reference to the drawings and embodiments. It should be understood that the particular embodiments described herein are only used to explain the invention and not intended to limit the invention.

Referring to FIGS. 1 to 13, a small water heater comprises a water inlet pipe 1, a pressure maintaining valve 2, a flow regulating valve 3, a water heating tank 4 and a water outlet pipe 5 which are sequentially arranged along the water flow direction, wherein the water flow path in the water inlet pipe 1, the pressure maintaining valve 2 and the flow regulating valve 3 is shown as line B in FIG. 4; the pressure maintaining valve 2 comprises a valve body 20 in which a valve seat 21, a valve core 22 and a vent member 23 are sequentially arranged along the water flow direction; both ends of the valve body 20 are communicated with the water inlet pipe 1 and the flow regulating valve 3 respectively; the valve seat 21 abuts against an inner wall of a water inlet end of the valve body 20, and a gap is left between the valve seat 21 and an inner wall of a water outlet end of the valve body 20; the valve seat 21 is internally provided with a water inlet chamber 210, a water through hole 211 is arranged on a side wall of the water inlet chamber 210, and water passes sequentially through the water inlet chamber 210 and the water through hole 211 from the water inlet end of the valve body 20 and flows into the water outlet end of the valve body 20; the valve core 22 comprises a sleeve 220 and a spring 221 sleeved in the sleeve 220; one end of the sleeve 220 is tightly sleeved outside the valve seat 21, and the sleeve 220 is driven to move by water pressure to adjust the opening size of the water through hole 211; one end of the vent member 23 is slidably connected to the sleeve 220, and the other end of the vent member 23 is fixedly connected to the valve body 20; the vent member 23 is internally provided with a vent hole 230; and one end of the vent hole 230 is communicated with an inner cavity of the sleeve 220, and the other end of the vent hole 230 is communicated with the outside of the valve body 20.

As shown in FIGS. 2, 4, 5 and 8, the water inlet pipe 1 comprises a cold water pipe 10, a socket pipe 11 and a connecting pipe 12; an upper end of the cold water pipe 10 is communicated with the water inlet end of the valve body 20, and water inlets 100 are respectively arranged on both sides of a lower end of the cold water pipe 10; one end of the connecting pipe 12 is fixed on the socket pipe 11 in a penetrating manner, and the other end of the connecting pipe 12 is communicated with a tap water pipe; and the socket pipe 11 is tightly sleeved outside the cold water pipe 10 at the water inlet 100, and the connecting pipe 12 is communicated with one of the water inlets 100 by rotating the socket pipe 11.

As shown in FIGS. 2, 4, 5, 7 and 8, the connecting pipe 12 is provided with an impurity removal mechanism 13 for intercepting impurities in water; the impurity removal mechanism 13 comprises an impurity removal pipe 130 and an impurity removal plug 131; the impurity removal pipe 130 is fixed on a lower side of the connecting pipe 12 in a penetrating manner; a filter screen 132 is fixed at an upper end of the impurity removal plug 131; the filter screen 132 is inserted into the connecting pipe 12 from bottom to top; and the impurity removal plug 131 is threadably connected to the impurity removal pipe 130.

As shown in FIGS. 6, 7 and 8, a spacing is left between the impurity removal plug 131 and the connecting pipe 12, and impurities intercepted by the filter screen 132 are precipitated in the impurity removal pipe 130 above the impurity removal plug 131.

As shown in FIGS. 9, 10, 11, 12 and 13, the cold water pipe 10 is provided with a first sealing groove 101 outside the water inlet 100; the first sealing groove 101 is provided with a first sealing ring 14; one side of the first sealing ring 14 is tightly embedded into the first sealing groove 101, and the other side thereof abuts against an inner wall of the socket pipe 11; the impurity removal plug 131 is provided with a second sealing groove 1310; the second sealing groove 1310 is provided with a second sealing ring 15; and one side of the second sealing ring 15 is tightly embedded into the second sealing groove 1310, and the other side thereof abuts against the impurity removal pipe 130.

As shown in FIGS. 2, 4, 5, 6 and 8, the cold water pipe 10 is internally provided with a water discharge pipe 102; an upper end of the water discharge pipe 102 is communicated with the water inlet end of the valve body 20, and a lower end of the water discharge pipe 102 is communicated with an inner cavity of the cold water pipe 10; and the cold water pipe 10 is provided with a solenoid valve 103, and water in the cold water pipe 10 is controlled by the solenoid valve 103 to flow from the water discharge pipe 102 to the pressure maintaining valve 2. FIG. 8 is a structural view when the solenoid valve 103 is closed, in which line A is a water flow path.

As shown in FIGS. 9, 10, 11, 12 and 13, a third sealing ring 24 is arranged at the position where the valve seat 21 contacts an inner wall of the valve body 20; the valve seat 21 is provided with a third sealing groove 212; one side of the third sealing ring 24 is tightly embedded into the third sealing groove 212, and the other side thereof abuts against the inner wall of the valve body 20; a fourth sealing ring is arranged at the position where the valve seat 21 contacts an inner wall of the sleeve 220; the valve seat 21 is provided with a fourth sealing groove 213; one side of the fourth sealing ring 25 is tightly embedded into the fourth sealing groove 213, and the other side thereof abuts against the inner wall of the sleeve 220; a fifth sealing ring 26 is arranged at the position where the sleeve 220 contacts the vent member 23; the sleeve 220 is provided with a fifth sealing groove 2200; and one side of the fifth sealing ring 26 is tightly embedded into the fifth sealing groove 2200, and the other side thereof abuts against the vent member 23.

As shown in FIGS. 11, 12 and 13, a plurality of reinforcing ribs 27 are fixed to the inner wall of the valve body 20 at intervals; and the reinforcing ribs 27 are located outside the sleeve 220.

As shown in FIGS. 1, 2 and 5, the water heating tank 4 comprises a water storage tank 40 and a heating element 41 disposed on the water storage tank 40, and water in the water storage tank 40 is heated by the heating element 41.

As shown in FIGS. 1, 2 and 3, the water heating tank 4 is internally provided with a water level pipe 42 for improving the water heating effect; a lower end of the water level pipe 42 is fixed on the water heating tank 4, and an upper end of the water level pipe 42 is located above a water outlet end of the flow regulating valve 3; and the water outlet end of the flow regulating valve 3 is communicated with a lower part of the water storage tank 40, the water outlet pipe 5 is communicated with the lower end of the water level pipe 42, and the heated water is discharged from the water outlet pipe 5 through the water level pipe 42.

The operating principle of the invention is as follows: when the small water heater of the invention is used, firstly, the first sealing ring 14 is placed in the first sealing groove 101, then the socket pipe 11 is sleeved outside the cold water pipe 10, and the connecting pipe 12 is mounted on one side that is conveniently connected to the tap water pipe by rotating the socket pipe 11 Ii according to the position of the tap water pipe (not shown) reserved in an actual application place; next, the impurity removal plug 131 is mounted on the impurity removal pipe 130 by rotation, so that the filter screen 132 extends into the connecting pipe 12 and can effectively intercept impurities in water, and the impurities are deposited together ill the impurity removal pipe 130 for centralized disassembly and cleanup; secondly, the filtered tap water flows into the cold water pipe 10 through the water inlet 100, and the water in the cold water pipe 10 flows to the water inlet end of the valve body 20 through the water discharge pipe 102 by opening the solenoid valve 103; subsequently, the water in the water inlet end of the valve body 20 flows into the water outlet end of the valve body 20 from the water inlet chamber 210 and the water through hole 211, the water accumulated in the water outlet end of the valve body 20 produces a downward reverse pressure on the sleeve 220, the pressure of the water flowing into the water outlet end of the valve body 20 increases as the water inlet pressure increases, the water pressure pushes the sleeve 220 downward to overcome the resistance of the spring 221 and move to one side of the water inlet end, and gas inside the sleeve 220 is discharged from the vent hole 230, so that the sleeve 220 gradually reduces the opening size of the water through hole 211, thus reducing the water flow to the water outlet end of the valve body 20; when the water flow to the water outlet end of the valve body 20 is too low, the sleeve 220 moves away from one side of the water inlet end of the valve body 20 under the action of the restoring force of the spring 221, so that the sleeve 220 gradually increases the opening size of the water through hole 211, thus increasing the water flow to the water outlet end of the valve body 20, and finally achieving a dynamic balance between the water outlet pressure and the restoring force of the spring 221 (the water flow speed can be adjusted adaptively according to the tap water pressure); and finally, the water stream at the water outlet end of the valve body 20 flows into the water storage tank 40 through the flow regulating valve 3, and when water is accumulated in the water storage tank 40 from bottom to top, the heating element 41 can effectively heat the water, and the heated water flows into a water inlet of the water level pipe 42 from the upper end and is finally discharged from the water outlet pipe 5; therefore, the small water heater can adaptively adjust the water flow speed according to the tap water pressure, and stabilize the water pressure provided by external tap water, which can effectively improve the heating stability of the small water heater, so that the temperature of the heated water is relatively stable, and the effect is good due to strong versatility of the water inlet pipe 1.

The above description only refers to preferred specific embodiments of the invention, but the protection scope of the invention is not limited thereto, and all changes or replacements which are readily contemplated by any one skilled in the art within the technical scope disclosed by the invention shall be covered within the protection scope of the invention. Accordingly, the protection scope of the invention should be based on the protection scope of the claims.

Claims

CLAIMS1. A small water heater, comprising a water inlet pipe (1), a pressure maintaining valve (2), a flow regulating valve (3), a water heating tank (4) and a water outlet pipe (5) which are sequentially arranged along the water flow direction; the pressure maintaining valve (2) comprising a valve body (20) in which a valve seat (21), a valve core (22) and a vent member (23) are sequentially arranged along the water flow direction; both ends of the valve body (20) being communicated with the water inlet pipe (1) and the flow regulating valve (3) respectively; the valve seat (21) abutting against an inner wall of a water inlet end of the valve body (20), and a gap being left between the valve seat (21) and an inner wall of a water outlet end of the valve body (20); the valve seat (21) being internally provided with a water inlet chamber (210), a water through hole (211) being arranged on a side wall of the water inlet chamber (210), and water passing sequentially through the water inlet chamber (210) and the water through hole (211) from the water inlet end of the valve body (20) and flowing into the water outlet end of the valve body (20); the valve core (22) comprising a sleeve (220) and a spring (221) sleeved in the sleeve (220); one end of the sleeve (220) being tightly sleeved outside the valve seat (21), and the sleeve (220) is driven to move by water pressure to adjust the opening size of the water through hole (211); one end of the vent member (23) being slidably connected to the sleeve (220), and the other end of the vent member (23) being fixedly connected to the valve body (20); the vent member (23) being internally provided with a vent hole (230); and one end of the vent hole (230) being communicated with an inner cavity of the sleeve (220), and the other end of the vent hole (230) being communicated with the outside of the valve body (20).
2. The small water heater according to claim 1, wherein the water inlet pipe (1) comprises a cold water pipe (10), a socket pipe (11) and a connecting pipe (12); an 14 upper end of the cold water pipe (10) is communicated with the water inlet end of the valve body (20), and water inlets (100) are respectively arranged on both sides of a lower end of the cold water pipe (10); one end of the connecting pipe (12) is fixed on the socket pipe (11) in a penetrating manner, and the other end of the connecting pipe (12) is communicated with a tap water pipe; and the socket pipe (11) is tightly sleeved outside the cold water pipe (10) at the water inlet (100), and the connecting pipe (12) is communicated with one of the water inlets (100) by rotating the socket pipe (11).
3. The small water heater according to claim 2, wherein the connecting pipe (12) is provided with an impurity removal mechanism (13) for intercepting impurities in water; the impurity removal mechanism (13) comprises an impurity removal pipe (130) and an impurity removal plug (131); the impurity removal pipe (130) is fixed on a lower side of the connecting pipe (12) in a penetrating manner; a filter screen (132) is fixed at an upper end of the impurity removal plug (131); the filter screen (132) is inserted into the connecting pipe (12) from bottom to top; and the impurity removal plug (131) is threadably connected to the impurity removal pipe (130).
4. The small water heater according to claim 3, wherein a spacing is left between the impurity removal plug (131) and the connecting pipe (12), and impurities intercepted by the filter screen (132) are precipitated in the impurity removal pipe (130) above the impurity removal plug (131).
5. The small water heater according to claim 4, wherein the cold water pipe (10) is provided with a first sealing groove (101) outside the water inlet (100); the first sealing groove (101) is provided with a first sealing ring (14); one side of the first sealing ring (14) is tightly embedded into the first sealing groove (101), and the other side thereof abuts against an inner wall of the socket pipe (11); the impurity removal plug (131) is provided with a second sealing groove (1310); the second sealing groove (1310) is provided with a second sealing ring (15); and one side of the second sealing ring (15) is tightly embedded into the second sealing groove (1310), and the other side thereof abuts against the impurity removal pipe (130).
6. The small water heater according to claim 2, wherein the cold water pipe (10) is internally provided with a water discharge pipe (102); an upper end of the water discharge pipe (102) is communicated with the water inlet end of the valve body (20), and a lower end of the water discharge pipe (102) is communicated with an inner cavity of the cold water pipe (10); and the cold water pipe (10) is provided with a solenoid valve (103), and water in the cold water pipe (10) is controlled by the solenoid valve (103) to flow from the water discharge pipe (102) to the pressure maintaining valve (2).
7. The small water heater according to claim 1, wherein a third sealing ring (24) is arranged at the position where the valve seat (21) contacts an inner wall of the valve body (20); the valve seat (21) is provided with a third sealing groove (212); one side of the third sealing ring (24) is tightly embedded into the third sealing groove (212), and the other side thereof abuts against the inner wall of the valve body (20); a fourth sealing ring (25) is arranged at the position where the valve seat (21) contacts an inner wall of the sleeve (220); the valve seat (21) is provided with a fourth sealing groove (213); one side of the fourth sealing ring (25) is tightly embedded into the fourth sealing groove (213), and the other side thereof abuts against the inner wall of the sleeve (220); a fifth sealing ring (26) is arranged at the position where the sleeve (220) contacts the vent member (23); the sleeve (220) is provided with a fifth sealing groove (2200); and one side of the fifth sealing ring (26) is tightly embedded into the fifth sealing groove (2200), and the other side thereof abuts against the vent member (23).
8. The small water heater according to claim 1, wherein a plurality of reinforcing ribs (27) are fixed to the inner wall of the valve body (20) at intervals; and the reinforcing ribs (27) are located outside the sleeve (220).
9. The small water heater according to claim 1, wherein the water heating tank (4) comprises a water storage tank (40) and a heating element (41) disposed on the water storage tank (40), and water in the water storage tank (40) is heated by the heating element (41).
10. The small water heater according to claim 9, wherein the water heating tank (4) is internally provided with a water level pipe (42) for improving the water heating effect; a lower end of the water level pipe (42) is fixed on the water heating tank (4), and an upper end of the water level pipe (42) is located above a water outlet end of the flow regulating valve (3); and the water outlet end of the flow regulating valve (3) is communicated with a lower part of the water storage tank (40), the water outlet pipe (5) is communicated with the lower end of the water level pipe (42), and the heated water is discharged from the water outlet pipe (5) through the water level pipe (42).