Leakage-proof sealing structure of fire valve
By combining the inward-expanding sealing components and the downward-pressing components, the problem of easy wear on the valve stem seal of fire valves is solved, achieving stable sealing under high temperature and high pressure environments and extending the service life of the valves.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-14
- Publication Date
- 2026-03-20
AI Technical Summary
The valve stem sealing parts of fire valves are prone to wear, leading to leakage. Especially under high temperature and high pressure conditions, the sealing surface separates, affecting the fire extinguishing effect. Furthermore, the water hammer effect accelerates the fatigue damage of the sealing structure.
The system employs a combined sealing structure consisting of an inner extrusion seat, an inner shrinkage sealant, an outer expansion seat, and an outer expansion sealant. Combined with a pressing assembly, pressure is applied through fastening bolts, causing the outer expansion sealant to expand radially and the inner shrinkage sealant to contract radially, forming a double sealing barrier. This is further enhanced by the lower bearing for auxiliary sealing.
It significantly improves the sealing performance between the valve stem and the cavity column, prevents media leakage, extends valve service life, and ensures stable sealing under frequent operation and high-pressure environments.
Smart Images
Figure CN224017735U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to fire fighting valve technical field, concretely relates to a fire fighting valve leakproof sealing structure. BACKGROUND
[0002] In prior art, fire fighting system generally adopts butterfly valve as main control valve, it has simple structure, opens and closes rapidly, small volume and other obvious advantages. However, in practical application, since fire fighting valve needs to be frequently operated and tested (according to NFPA25 standard requirement, at least monthly open and close operation), in addition to the characteristics of needing to be quickly opened and closed in emergency state, lead to the sealing part of valve stem bears extremely high mechanical wear. According to statistics, in fire fighting valve failure case, about 68% of leakage problems occur in valve stem sealing area, mainly show that: permanent deformation is generated under frequent axial friction for traditional packing seal, graphite packing is prone to particle drop and form leakage passage, O-ring seal leads to elastic failure due to long-term extrusion. Especially in high temperature and high pressure working condition (such as water pump outlet end), the existing sealing structure is more prone to sealing surface separation problem caused by uneven thermal expansion. In addition, the water hammer effect in fire fighting pipeline system can produce instantaneous high pressure impact (up to 4-6 times of working pressure), further accelerate the fatigue damage of sealing structure. These problems directly lead to the decline of valve sealing performance, not only cause water resource waste, more seriously, when fire occurs, the system pressure may be insufficient due to valve leakage, affect the fire extinguishing effect. For this reason, the utility model provides a fire fighting valve leakproof sealing structure to solve the above problems. SUMMARY
[0003] The utility model aims at providing a fire fighting valve leakproof sealing structure, which can solve the above technical problems.
[0004] The technical scheme adopted by the utility model is as follows:
[0005] The fire fighting valve leakproof sealing structure provided by the utility model comprises a valve body, a valve flap, a cavity column, a valve rod and a sealing assembly, the cavity column is integrally connected with the valve body, the valve rod penetrates the cavity column and the upper side of the valve body and is connected with the valve flap, and the sealing assembly is arranged in the cavity column and connected with the valve rod.
[0006] The sealing assembly comprises an inner extruding seat, an inner retraction sealing material, an outer expansion seat and an outer expansion sealing material, which are arranged in the cavity column, the lower bearing is arranged on the inner bottom surface of the cavity column and is in interference fit with the valve rod, the sealing ring is arranged in the cavity column and is sleeved on the outer periphery of the lower bearing, the inner extruding seat is abutted on the lower bearing and is sleeved on the valve rod in sliding mode, the inner retraction sealing material is arranged in the inner retraction groove which is arranged on the surface of the inner extruding seat, the outer expansion seat is pressed on the inner retraction sealing material and is sleeved on the valve rod in sliding mode, and the outer expansion sealing material is sleeved on the outer expansion taper which is integrally arranged on the outer expansion seat.
[0007] The cavity column is provided with the pressing ring which is pressed on the outer expansion sealing material, and the lower pressing assembly is arranged on the upper side of the cavity column and presses the pressing ring along the inner wall of the cavity column.
[0008] Preferably, the lower pressing assembly comprises a lower pressing cylinder, a fixed disc and fastening bolts, the fixed disc is integrally arranged on the outer periphery of the upper side of the cavity column, the fastening disc is arranged on the surface of the fixed disc in abutting mode, the fastening disc is integrally arranged on the upper side of the lower pressing cylinder, the clamping groove disc which is matched with the handle is arranged on the surface of the fastening disc in abutting mode, the clamping groove disc is sleeved on the mounting ring which is fixed on the fastening disc, and the upper bearing is arranged in interference fit on the valve rod and is mounted in the mounting ring.
[0009] Preferably, the fastening bolts are arranged in plurality and are distributed in the circumferential direction of the valve rod at an interval of 90° and penetrate the clamping groove disc, the fastening disc and the fixed disc to press the lower pressing cylinder.
[0010] Preferably, the pressing force of the lower pressing assembly on the outer expansion sealing material and the inner retraction sealing material is not less than 0.8 MPa.
[0011] Preferably, the outer expansion sealing material and the inner retraction sealing material are both made of aramid fiber packing and are wound on the valve rod.
[0012] Preferably, the upper bearing and the lower bearing are both made of sealing bearing.
[0013] The beneficial effects are as follows:
[0014] The utility model discloses a cooperation through sealing assembly and lower pressure subassembly, can make the fastening disc on lower pressure subassembly under the action of fastening bolt, drive lower pressure cylinder and exert lower pressure to sealing assembly and compression ring. The pressure is transmitted to the outer expansion sealing material, makes it produce radial expansion along the inclined surface of outer expansion cone, thereby tightly fits the first seal of cavity column inner wall, simultaneously, the axial pressure of outer expansion sealing material promotes the descending of outer expansion seat, and then extrudes the radial contraction of inner contraction sealing material in the inner contraction groove, realizes the second seal to the surface of valve stem. The double sealing mechanism makes the inside and outside two -way sealing barrier between valve stem and cavity column, cooperates the auxiliary sealing effect of lower bearing, improves the overall sealing performance significantly. The structure not only prevents medium leakage effectively, but also can maintain stable sealing pressure when the valve stem is frequently rotated, thereby prolongs the service life of valve. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is the front structure schematic diagram of the utility model;
[0016] Figure 2 It is the cavity column position section view structure schematic diagram of the utility model's valve body;
[0017] Figure 3 It is the sealing assembly position schematic diagram of the utility model's valve stem;
[0018] Figure 4 It is the sealing assembly explosion state schematic diagram of the utility model.
[0019] In the drawings, the component list of each sign is as follows:
[0020] 1, valve body;2, valve flap;3, cavity column;4, valve stem;5, lower bearing;6, upper bearing;7, inner extrusion seat;7a, inner contraction groove;8, inner contraction sealing material;9, outer expansion seat;9a, outer expansion cone;10, outer expansion sealing material;11, compression ring;12, lower pressure cylinder;12a, fastening disc;13, fixed disc;14, fastening bolt;15, clamping groove disc. DETAILED DESCRIPTION
[0021] In order to make the purpose and the advantage of the utility model more clearly clear, the following specific description of the utility model is combined with example. It should be understood that the following text is only used to describe one or several specific implementation manners of the utility model, and does not strictly limit the protection scope of the utility model specific request.
[0022] As Figures 1-4 Shown, a kind of fire-fighting valve leakage prevention sealing structure, including valve body 1, valve flap 2, cavity column 3, valve stem 4 and sealing assembly, cavity column 3 is integrally connected with valve body 1, valve stem 4 is connected with valve flap 2 by being threaded through cavity column 3 and the upper side of valve body 1, sealing assembly is set in cavity column 3, and is connected with valve stem 4;
[0023] The sealing assembly comprises an inner extrusion seat 7, an inner retraction sealing material 8, an outer expansion seat 9 and an outer expansion sealing material 10, which are all arranged in the cavity column 3. The lower bearing 5 is arranged on the bottom surface of the cavity column 3 and is in interference fit with the valve rod 4. A sealing ring is arranged in the cavity column 3 and is sleeved on the outer periphery of the lower bearing 5. The inner extrusion seat 7 is abutted on the lower bearing 5 and is sleeved on the valve rod 4 in sliding mode. The inner retraction sealing material 8 is arranged in the inner retraction groove 7a which is formed on the surface of the inner extrusion seat 7. The outer expansion seat 9 is pressed on the inner retraction sealing material 8 and is sleeved on the valve rod 4 in sliding mode. The outer expansion sealing material 10 is sleeved on the outer expansion cone 9a which is integrally arranged on the outer expansion seat 9.
[0024] The cavity column 3 is provided with a pressing ring 11 which is pressed on the outer expansion sealing material 10. The lower side of the cavity column 3 is provided with a pressing assembly which presses the pressing ring 11 along the inner wall of the cavity column 3.
[0025] As an optional embodiment, the pressing assembly comprises a pressing cylinder 12, a fixing disc 13 and fastening bolts 14. The fastening bolts 14 comprise screws and nuts which are in threaded fit. The fixing disc 13 is integrally arranged on the outer periphery of the upper side of the cavity column 3. The surface of the fixing disc 13 is provided with a fastening disc 12a which is integrally arranged on the upper side of the pressing cylinder 12. The surface of the fastening disc 12a is provided with a clamping groove disc 15 which is in fit with a handle. The clamping groove disc 15 is sleeved on a mounting ring which is fixed on the fastening disc 12a. The valve rod 4 is provided with an upper bearing 6 which is in interference fit and is mounted in the mounting ring. In this way, when the fastening disc 12a is axially displaced, the upper bearing 6 can slide along the valve rod 4, thereby ensuring that the fastening disc 12a can press the sealing assembly.
[0026] Referring to Figs. 1 to 3, Figure 2 The fastening bolts 14 are arranged in multiple numbers and are distributed at intervals of 90° around the valve rod 4 as the center and penetrate the clamping groove disc 15, the fastening disc 12a and the fixing disc 13 to press the pressing cylinder 12. In this way, the fastening bolts 14 can press the clamping groove disc 15 and the fastening disc 12a by means of the nuts on the fastening bolts 14, thereby exerting a pressing force on the pressing ring 11 to press the sealing assembly.
[0027] Referring to Figs. 1 to 3, Figure 3 and Figs. 4 to 6, Figure 4 The pressing force of the outer expansion sealing material 10 and the inner retraction sealing material 8 under the pressing assembly is not less than 0.8 MPa. In this way, the inner retraction sealing material 8 and the outer expansion sealing material 10 can be kept under pressure, thereby improving the sealing strength of the cavity column 3 and the valve rod 4.
[0028] Further, the outer expansion sealing material 10 and the inner contraction sealing material 8 are both wrapped around the valve stem 4 by using a wrapping shape, so that when the pressing assembly is pressed, the wrapping is pressed and changes along the shape of the inner contraction groove 7a and the outer expansion cone 9a, thereby achieving extrusion sealing of the valve stem 4 and the inner wall of the cavity column 3, and improving the sealing effect.
[0029] Further, the upper bearing 6 and the lower bearing 5 are both sealing bearings, thereby improving the rotating sealing effect of the valve stem 4.
[0030] By using the above structure, the valve stem 4 can form a double sealing barrier by the outer expansion sealing material 10 and the inner contraction sealing material 8 of the sealing assembly during rotation, and the auxiliary sealing effect of the lower bearing 5 can significantly improve the overall sealing performance of the valve stem 4. The structure can effectively cope with frequent rotating conditions, maintain stable sealing effect for a long time, thereby prolonging the service life of the valve.
[0031] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application. The standard parts used in the present application can be purchased from the market, and can be customized according to the description and drawings. The specific connection mode of each part adopts the conventional means such as bolt, rivet and welding in the prior art. The mechanical parts and equipment adopt the conventional type in the prior art, and the present application mainly protects the mechanical device. The structures, devices and operation methods not specifically described and explained in the present application are implemented according to the conventional means in the art, unless otherwise specified and limited.
Claims
1. A leak-proof sealing structure for fire-fighting valves, characterized in that: It includes a valve body (1), a valve disc (2), a cavity column (3), a valve stem (4), and a sealing assembly. The cavity column (3) is integrally connected to the valve body (1). The valve stem (4) passes through the cavity column (3) and the upper side of the valve body (1) and is connected to the valve disc (2). The sealing assembly is disposed in the cavity column (3) and is connected to the valve stem (4). The sealing assembly includes an inner extrusion seat (7), an inner sealing material (8), an outer expansion seat (9), and an outer expansion sealing material (10). The inner extrusion seat (7), inner sealing material (8), outer expansion seat (9), and outer expansion sealing material (10) are all disposed within a cavity column (3). A lower bearing (5) is disposed on the bottom surface of the cavity column (3), and the lower bearing (5) is interference-fitted with the valve stem (4). A sealing ring is disposed within the cavity column (3), and the sealing ring is fitted onto the lower bearing (7). 5) On the outer periphery, the inner extrusion seat (7) abuts against the lower bearing (5) and is slidably sleeved on the valve stem (4). The inner sealing material (8) is set in the inner groove (7a), and the inner groove (7a) is opened on the surface of the inner extrusion seat (7). The outer expansion seat (9) presses on the inner sealing material (8) and is slidably sleeved on the valve stem (4). The outer expansion sealing material (10) is sleeved on the outer expansion cone (9a), and the outer expansion cone (9a) is integrally set on the outer expansion seat (9). A pressure ring (11) is provided inside the cavity column (3), and the pressure ring (11) presses on the outer sealing material (10). A pressing assembly is provided on the upper side of the cavity column (3) and presses the pressure ring (11) down along the inner wall of the cavity column (3).
2. The fire valve anti-leakage sealing structure according to claim 1, characterized in that: The pressing assembly includes a pressing cylinder (12), a fixed plate (13), and a fastening bolt (14). The fixed plate (13) is integrally fixed on the outer periphery of the upper side of the cavity column (3). A fastening plate (12a) is attached to the surface of the fixed plate (13). The fastening plate (12a) is integrally set on the upper side of the pressing cylinder (12). A slotted plate (15) that mates with the handle is attached to the surface of the fastening plate (12a). The slotted plate (15) is fitted onto the mounting ring, and the mounting ring is fixed on the fastening plate (12a). An upper bearing (6) is interference-fitted onto the valve stem (4), and the upper bearing (6) is installed inside the mounting ring.
3. The fire valve anti-leakage sealing structure according to claim 2, characterized in that: The fastening bolts (14) are arranged in multiples and distributed at 90° intervals around the valve stem (4) in the circumferential direction. They pass through the slot plate (15), the fastening plate (12a) and the fixing plate (13) to press down the pressure cylinder (12).
4. The fire valve anti-leakage sealing structure according to claim 3, characterized in that: The externally expanding sealant (10) and the internally contracting sealant (8) are subjected to a clamping force of not less than 0.8 MPa by the pressing component.
5. The anti-leakage sealing structure for a fire valve according to claim 4, characterized in that: Both the outward-expanding sealant (10) and the inward-retracting sealant (8) are made of aramid fiber packing and are wound around the valve stem (4).
6. The anti-leakage sealing structure for a fire valve according to claim 5, characterized in that: Both the upper bearing (6) and the lower bearing (5) are sealed bearings.