High-strength diaphragm for reducing valve of EPDM (Ethylene-Propylene-Diene Monomer) screen clamping type nylon fiber

Abstract

The utility model discloses an EPDM (Ethylene-Propylene-Diene Monomer) screen mesh type nylon fiber clamping high-strength diaphragm for a pressure reducing valve, which comprises an upper EPDM rubber layer (1), a screen mesh type nylon fiber reinforcing layer (2) and a lower EPDM rubber layer (3) which are coaxially overlapped to form the diaphragm, and an annular external pressure water line (4) is arranged at the circumference of the working surface of the diaphragm, which is 10mm away from the circle center of the diaphragm. And an annular internal pressure waterline (5) is arranged at the circumference which is 20mm away from the circle center of the diaphragm. The utility model has the beneficial effects that: 1, the nylon fiber screen cloth disperses stress, and the tensile strength is improved by more than or equal to 150%; 2, the anti-fatigue times can reach more than 300,000 times, and the service life is 2-3 times of that of the traditional diaphragm; 3, the double-pressure waterline design ensures zero leakage of high-pressure sealing; and 4, the thickness is optimized to 1.2 mm, and both the flexibility and the pressure bearing capacity are considered.

Description

Technical Field

[0001] This utility model relates to the field of fluid control equipment, and in particular to a sealing diaphragm structure for pressure reducing valves and pilot valves. Background Technology

[0002] Existing pressure reducing valve diaphragms mostly use pure rubber or simple fabric-reinforced structures, which have problems such as easy deformation, poor pressure resistance, and short life (usually ≤100,000 cycles). Especially under high pressure differential conditions, traditional diaphragms are prone to central tearing or edge creep failure.

[0003] For example, Chinese invention patent publication number CN103016806A discloses a high-strength composite diaphragm and diaphragm assembly for a pressure reducing valve. The diaphragm has a ring-shaped structure, including a metal gasket, a cotton cloth layer, and two rubber composite layers. The diameter of the cotton cloth layer is equal to the diameter of the rubber layer and is located between the two rubber composite layers. The diameter of the metal gasket is smaller than the diameter of the rubber layer and is located between the cotton cloth layer and one of the rubber composite layers. Under high pressure, the cotton cloth layer of this patented diaphragm is still prone to central tearing or edge creep failure. Utility Model Content

[0004] The technical problem to be solved by this invention is that the existing pressure reducing valve diaphragm structure is prone to central tearing or edge creep failure. To address this, a high-strength diaphragm for pressure reducing valves with EPDM sandwiched with mesh-type nylon fibers is provided.

[0005] The technical solution of this utility model is: a high-strength diaphragm for a pressure reducing valve with EPDM sandwiched with mesh-type nylon fibers, characterized in that: it includes an upper EPDM rubber layer, a mesh-type nylon fiber reinforcing layer and a lower EPDM rubber layer coaxially stacked together, and an annular outer pressure water line is provided on the working surface of the diaphragm at a distance of 10mm from the center of the diaphragm, and an annular inner pressure water line is provided at a distance of 20mm from the center of the diaphragm.

[0006] The depth of the annular outer pressure water line and the annular inner pressure water line in the above scheme is 0.2 mm.

[0007] In the above scheme, the sieve-type nylon fiber reinforcement layer has a warp and weft woven structure with a mesh density of 20-40 mesh and a fiber diameter of 0.1-0.3 mm.

[0008] In the above scheme, the thickness ratio of the upper EPDM rubber layer to the lower EPDM rubber layer is 1:1 to 1.2.

[0009] The cross-sections of the external and internal pressure water lines described in the above scheme are U-shaped or V-shaped grooves.

[0010] The overall thickness of the diaphragm in the above scheme is 1.2 to 2.0 mm, and the diameter is 60 to 85 mm.

[0011] The beneficial effects of this utility model are: 1. Nylon fiber screen disperses stress and increases tensile strength by ≥150%; 2. It can withstand more than 300,000 fatigue cycles, and its lifespan is 2-3 times that of traditional diaphragms; 3. The dual pressure water line design ensures high-pressure sealing with zero leakage; 4. The thickness is optimized to 1.2mm, which takes into account both flexibility and pressure bearing capacity. Attached Figure Description

[0012] Figure 1 This is a cross-sectional structural diagram of the present invention;

[0013] Figure 2 This is a schematic diagram of the present invention;

[0014] In the diagram, 1 is the upper EPDM rubber layer, 2 is the screen-type nylon fiber reinforcement layer, 3 is the lower EPDM rubber layer, 4 is the annular outer water pressure line, and 5 is the annular inner water pressure line. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] like Figure 1-2 As shown, a high-strength diaphragm for a pressure-reducing valve, comprising an upper EPDM rubber layer 1, a screen-type nylon fiber reinforcing layer 2, and a lower EPDM rubber layer 3 coaxially stacked, includes an outer annular pressure line 4 located 10 mm from the center of the diaphragm on its working surface, and an inner annular pressure line 5 located 20 mm from the center of the diaphragm. The screen-type nylon fiber reinforcing layer 2 has a warp and weft woven structure with a mesh density of 20, 30, or 40 mesh and fiber diameters of 0.1 mm, 0.2 mm, or 0.3 mm. The thickness ratio of the upper EPDM rubber layer 1 to the lower EPDM rubber layer 3 is 1:1 or 1.2. The cross-sections of the outer pressure line 4 and the inner pressure line 5 are U-shaped or V-shaped grooves. The overall thickness of the diaphragm is 1.2 mm, 1.8 mm, or 2.0 mm, and the diameter is 60 mm, 70 mm, or 85 mm.

[0017] The core structure includes: a three-layer composite structure: an upper EPDM rubber layer 1 + a screen-type nylon fiber layer 2 + a lower EPDM rubber layer 3, which are integrally formed through a vulcanization process; a reinforcing layer design: nylon fibers are woven into a screen-like structure (preferably 30 mesh), and the fibers and EPDM form a mechanical interlock to prevent crack propagation; a water pressure line layout: a V-shaped water pressure line with a depth of 0.3mm is set in the key sealing areas (at radii of 10mm and 20mm) to improve the fit of the valve seat.

[0018] Specific embodiment: Take a 79mm diameter circular nylon screen (30 mesh, 0.25mm thick) and sandwich it between two layers of EPDM compound; set a raised ring in the mold and form a V-shaped water pressure line with a depth of 0.3mm at a radius of 10mm / 20mm; vulcanization conditions: 160℃×15min, pressure 12MPa; finished product thickness 1.6mm, tested to withstand a pressure difference of 2.5MPa, with a lifespan of 350,000 cycles.

[0019] Those skilled in the art should know that the protection scheme of this utility model is not limited to the above embodiments, and various arrangements, combinations and transformations can be made on the basis of the above embodiments. Without violating the spirit of this utility model, all transformations made to this utility model fall within the protection scope of this utility model.

Claims

1. A high-strength diaphragm for a pressure reducing valve made of EPDM with interlocking mesh-type nylon fibers, characterized in that: The membrane consists of an upper EPDM rubber layer (1), a screen-type nylon fiber reinforcement layer (2), and a lower EPDM rubber layer (3) formed by coaxial stacking. The membrane has an annular outer water pressure line (4) at a distance of 10 mm from the center of the membrane and an annular inner water pressure line (5) at a distance of 20 mm from the center of the membrane.

2. The high-strength diaphragm for a pressure-reducing valve with EPDM sandwiched nylon fibers as described in claim 1, characterized in that: The depth of the outer and inner annular pressure lines is 0.2 mm.

3. The high-strength diaphragm for a pressure-reducing valve with EPDM sandwiched mesh nylon fibers as described in claim 1, characterized in that: The screen-type nylon fiber reinforcement layer (2) has a warp and weft woven structure with a mesh density of 20-40 mesh and a fiber diameter of 0.1-0.3 mm.

4. The high-strength diaphragm for a pressure-reducing valve with EPDM sandwiched nylon fibers as described in claim 1, characterized in that: The thickness ratio of the upper EPDM rubber layer (1) to the lower EPDM rubber layer (3) is 1:1 to 1.

2.

5. The high-strength diaphragm for a pressure-reducing valve with EPDM sandwiched mesh nylon fibers as described in claim 1, characterized in that: The cross-sections of the external pressure water line (4) and the internal pressure water line (5) are U-shaped or V-shaped grooves.

6. The high-strength diaphragm for a pressure-reducing valve with EPDM sandwiched mesh nylon fibers as described in claim 1, characterized in that: The overall thickness of the diaphragm is 1.2–2.0 mm, and the diameter is 60–85 mm.

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