JPH09159075A - Insulation valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent potential difference corrosion due to a natural potential difference between different kinds of metals by filling an adhesive provided with an insulating property between the inner circumference part, of an outer cylinder and the outer circumference face part of an insertion cylinder facing the inner circumferential face part, and fixing the outer cylinder and the insertion cylinder together. SOLUTION: In an insulation valve 1, an epoxy group adhesive 27 is applied to the tip part of an insertion cylinder 9 or to the inner circumferential face part of a housing part 15 in the depth end of an outer cylinder 8 in which the tip part of the insertion cylinder 9 is positioned, and then, the insertion cylinder 9 is inserted. A synthetic resin screw part 16 is firmly screwed to an internal thread 14 in the outer cylinder 8. In this way, an insulating means 6 clamping the second flange 25 in a resin core 12 is formed between the outer cylinder 8 and the tip of the insertion cylinder 9. An external thread 13 in the outer cylinder 8 in the insulating means 6 is screwed to an internal thread 7 formed in a mounting port, 5 of a valve main body 4, and consequently, the insulation valve 1 is accomplished. In this way, an external thread part 19 in the pipe end of a lining steel pipe 18 is screwed to the insulating means 6, and the lining steel pipe 18 is connected to the insulation valve 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating valve useful for connecting a metal tube having a natural potential different from that of a metal material forming a valve body, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a water supply pipe, a lining steel pipe having an inner surface lined with a resin so as to prevent rust and red water from being generated inside is used. As a pipe joint for connecting the middle of the water supply pipe using such a lining steel pipe, for example, there is an electrically insulated pipe joint as shown in Japanese Utility Model Laid-Open No. 58-76889, and as an insulating valve provided in the middle of the water supply pipe. There is an insulating valve as disclosed in Japanese Patent Laid-Open No. 2-134479.

The insulating valve described in Japanese Patent Laid-Open No. 2-134479, as shown in FIG.
The lining steel pipe 103 is connected by screwing the male screw portion 104 provided on the outer peripheral surface of the end of the lining steel pipe 103 into the female screw portion 102 provided on the inner peripheral surface of the receiving port 101. At the same time, a cylindrical resin core 105 is provided so as to face the female threaded portion 102, and at the same time when the lining steel pipe 103 is connected, the resin core 105 closely adheres to the inner peripheral surface of the lining steel pipe 103, The steel pipe portion 106 exposed at the pipe end of the steel pipe 103 is prevented from being exposed to hot water or water flowing in the pipe to cause rust.

[0004]

By the way, a hot water supply line such as a water heater for heating and supplying water supplied from a water supply pipe is connected using a valve made of a corrosion-resistant copper alloy or stainless steel. Often. However, even if the valve 100 as described above is used and the steel pipe portion 106 at the pipe end of the lining steel pipe 103 is not exposed to the hot water or water flowing in the pipe by the resin core 105, the copper alloy forming the valve Since copper and steel have different natural potentials from each other, when used for a long period of time, potential difference corrosion occurs due to the difference in natural potential at the screw connection portion between the steel pipe 103 and the valve 100, and the screws disappear and the steel pipe 103 disappears. There is a problem that is missing.

Therefore, in order to solve such a problem, for example, a method in which a valve having a structure similar to that of the insulating pipe joint disclosed in Japanese Utility Model Laid-Open No. 58-76889 is interposed between the valve and the steel pipe is partly used. Although implemented, in the case of this method, an insulating joint must be prepared separately, and
Workability is extremely poor because an extra step is required to connect the valve and the insulating joint.

Although the above description is a problem at the time of screw joining, a similar problem occurs even when the portion for joining the lining steel pipe has a flange structure or a union structure. Therefore, according to the present invention, even if the portion for joining the lining steel pipe is directly connected to the dissimilar metal pipe having the flange structure or the union structure, the dissimilar metal contact corrosion can be completely prevented, and the manufacturing process is simple and the manufacturing cost is low. It is an object of the present invention to provide an insulating valve and a manufacturing method thereof that can reduce the above.

[0007]

In order to achieve such an object, an insulation valve according to the invention of claim 1 (hereinafter referred to as "first invention") is at least an outer peripheral surface or an inner peripheral surface of a tip. A metal valve main body having a tubular portion with a threaded portion formed on its surface, and an insulating means fixed to the tubular portion of the valve main body, the insulating means being mounted on the outer cylinder and inside the outer cylinder. The insertion cylinder, a resin fixing member provided on the outer peripheral portion of the insertion cylinder, and a resin core provided on the inner side of the valve body and the insertion cylinder. The outer cylinder and the insertion cylinder are fixed to each other by filling an insulating adhesive between the outer cylinder and the outer peripheral surface of the insertion cylinder.

The invention according to claim 2 "hereinafter, referred to as" second
The invention is described as "Invention"), in which a seal ring having elasticity is interposed between the corner portion of the inner peripheral surface of the outer cylinder and the tip portion of the outer peripheral surface of the insertion cylinder facing the corner portion. is there. In the configurations of the first and second inventions described above, the metal constituting the valve body is not particularly limited, and examples thereof include stainless steel, iron, copper, gun metal, bronze and the like.

The types of valves include ball valves, gate valves, check valves, strainers, pressure reducing valves and the like. The synthetic resin that constitutes the resin core is preferably as strong as possible and is not particularly limited. For example, polyvinyl chloride, polyethylene, polybutene, polypropylene, ABS resin, polyvinylidene fluoride (PVDF), polyamide (nylon) , Polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and the like, and a composite material of these resins and glass fiber, carbon fiber, or the like may be used.

The metal forming the insertion tube is not particularly limited, but stainless steel, iron, copper, gun metal, bronze and the like can be mentioned. The adhesive is not particularly limited, and examples thereof include an epoxy resin adhesive.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical sectional side view showing a first embodiment of an insulation valve according to the present invention. This valve 1 is a ball valve,
A ball valve body 3 that is rotated by a rotary knob 2, a valve body 4 made of bronze casting for rotatably housing the ball valve body 3, and a ball valve body 3 formed on the side of the ball valve body 3. The insulating means 6 is attached to the attached mounting port (cylindrical portion) 5.

The mounting port 5 is formed in a cylindrical shape laterally of the ball valve body 3, and an internal thread 7 is engraved on the inner peripheral surface portion thereof. The insulating means 6 attached to the mounting port 5 is
An outer cylinder 8 made of the same material as the valve body 4 and formed into a substantially cylindrical shape.
And an insertion cylinder 9 mounted inside the outer cylinder 8, and a rotation-preventing concavo-convex (knurl) provided on the outer peripheral portion of the insertion cylinder 9.
The fixing member 11 made of resin is fixed at 10, and the resin core 12 is provided inside the outer cylinder 8 and the insertion cylinder 9.

The outer cylinder 8 has a small-diameter portion on one side to be mounted in the mounting port 5, and a male screw 13 to be screwed into the female screw 7 of the mounting port 5 on the outer peripheral surface of the small-diameter portion.
Is formed, and an internal thread 14 for screwing the resin-made fixing member 11 is formed on the inner peripheral surface of the other side portion, and the distal end portion of the insertion tube 9 is housed at the rear end of the internal thread 14. A storage portion 15 is formed.

The insertion tube 9 is made of an iron-based material, and has a thickness of 0.2 to 1.0 mm between the accommodating portion 15 and the outer peripheral surface of the distal end portion of the insertion tube 9 accommodated therein. It is formed in a cylindrical shape having an outer diameter formed so as to form a gap. Further, a synthetic resin male screw (resin fixing member) 16 having an insulating property that is screwed into the female screw 14 is provided in a portion of the outer cylinder 8 facing the female screw 14, and an inner circumference that abuts on the resin core 12 is provided. A female screw 20 to which a male screw 19 of a lining steel pipe 18 having a resin lining 17 is screwed is formed on the surface portion.

Here, it is a preferable numerical value that the clearance between the storage portion 15 at the innermost end of the outer cylinder 8 and the insertion cylinder 9 is 0.2 to 1.0 mm. ,
It is not limited to this. That is, when the thickness of the insulating adhesive layer filled in the gap between the inner peripheral surface of the housing portion 15 at the rear end of the outer cylinder 8 and the insertion cylinder 9 is 0.2 mm or less, the insulation resistance value decreases. Not only that, but also because it becomes inflexible and it becomes impossible to cope with misalignment with the lining steel pipe 18 to be connected, and when the thickness of the adhesive layer exceeds 1.0 mm, the adhesive strength decreases. It is due to.

In this male screw 16 made of synthetic resin, the outer diameter of the insertion cylinder 9 of the relevant portion is made small, and the surface portion is knurled to form the anti-rotation unevenness 10.
The synthetic resin layer 21 is formed on the anti-rotation protrusions and recesses 10, and then the male screw 16 that fits into the female screw 14 of the outer cylinder 8 is formed on the surface of the synthetic resin layer 21. The inner peripheral edge portions of both ends of the are fitted into annular retaining fitting grooves 22 formed in the insertion tube 9.

The resin core 12 is formed by molding the outer cylinder 8 and then inwardly of the outer cylinder 8.
To form a tubular shape in which a first flange 24 fitted in a fitting groove 23 formed on the inner peripheral surface of the male screw 13 side and a second flange 25 sandwiched between the outer cylinder 8 and the tip of the insertion cylinder 9 are formed. A plurality of annular projections 26 are formed on a portion of the inner peripheral surface of the lining steel pipe 18 attached to the female screw 20 of the insertion tube 9 that abuts the lining 17.

Although the resin core 12 is formed by being cast into the outer cylinder 8, it goes without saying that the resin core 12 may be formed as a separate body and incorporated into the outer cylinder 8. In the insulation valve 1 configured as described above, first, the epoxy resin adhesive 27 is applied to the inner peripheral surface portion of the housing portion 15 at the distal end portion of the insertion cylinder 9 or the outer end of the outer cylinder 8 where the insertion cylinder 9 is located. Then, the insertion cylinder 9 is inserted and the synthetic resin screw portion 16 is securely screwed into the female screw 14 of the outer cylinder 8, and the second flange 25 of the resin core 12 is provided between the outer cylinder 8 and the tip of the insertion cylinder 9. The insulating means 6 in a state in which is sandwiched is assembled.

The insulating valve 1 is formed by screwing the assembled insulating means 6 with the male screw 13 of the outer cylinder 8 thereof to the female screw 7 formed in the mounting port 5 of the valve body 4. After that, the male threaded portion 19 at the pipe end of the lining steel pipe 18 is screwed to connect the lining steel pipe 18 to the insulating valve 1.
, The resin core 12 is fitted inside the inner surface of the lining 17 of the lining steel pipe 18, and the annular projection 2 on the surface
Since it adheres in a watertight manner at 6, the steel pipe portion exposed at the pipe end of the lining steel pipe 18 will not be corroded by being exposed to hot water or water flowing in the pipe, and it will endure long-term use.

Further, since the structure is such that only the insulating means 6 is attached to the valve body 4, the assembly can be provided easily and at a low cost. Next, a second embodiment of the insulation valve will be described with reference to FIG. FIG. 2 is a vertical cross-sectional side view of the insulation valve 1. What is different from the insulation valve 1 shown in the first embodiment is that it is formed at the inner end of the inner peripheral surface of the housing portion 15 of the outer cylinder 8. That is, a seal ring (O-ring) 29 having elasticity is interposed between the corner portion 28 and the tip portion 30 of the outer peripheral surface of the insertion cylinder 9 facing the corner portion 28.

In such an insulating valve 1, the seal ring 29 greatly improves the water tightness between the outer cylinder 8 and the insertion cylinder 9,
The durability will be even higher. In each of the above embodiments, a female screw is formed at the mounting opening of the valve body, but it may be a male screw. In this case, the insulating means fitted here is a female screw and is externally fitted. It is a structure that allows it.

[0022]

As described above, in the insulated valve according to the present invention, the valve body and the piping material do not come into direct contact with each other even if the valve body and the piping material having a different natural potential are connected. Therefore, the piping material does not cause the potential difference corrosion due to the contact of different metals without using the individually formed and complicated insulating joint.

Moreover, when the pipe material is a lining steel pipe, the outer peripheral surface of the resin core is watertightly adhered to the inner peripheral surface of the lining steel pipe, so that the steel pipe portion exposed at the pipe end of the lining steel pipe flows in the pipe. It is not directly exposed to hot water or water, and the steel pipe part is not exposed to hot water or water and corroded. Further, in the case where a seal ring having elasticity is interposed between the corner portion of the inner peripheral surface of the outer cylinder and the tip portion of the outer peripheral surface of the insertion cylinder facing the inner peripheral surface, the watertightness between the outer cylinder and the insertion cylinder is reduced. Therefore, bleeding of hot water or water can be reliably prevented, and the steel pipe portion is not exposed to hot water or water and corroded, and its durability can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an insulation valve according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of an insulation valve according to the present invention.

FIG. 3 is a vertical sectional side view of a conventional insulation valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulation valve 4 ... Valve main body 5 ... Cylindrical part (mounting port) 6 ... Insulating means 7 ... Screw part (female screw) 8 ... Outer cylinder 9 ... Insertion cylinder 11・ ・ ・ Resin fixing member 12 ・ ・ ・ Resin core 28 ・ ・ ・ Corner part 29 ・ ・ ・ Seal ring (O-ring)

Claims (2)

[Claims] 1. A metal valve main body having a cylindrical portion having a mounting screw formed on at least an outer peripheral surface or an inner peripheral surface of the tip, and an insulating means fixed to the cylindrical portion of the valve main body.
The insulating means is provided over the outer cylinder, the insertion cylinder mounted inside the outer cylinder, the resin fixing member provided on the outer peripheral portion of the insertion cylinder, and the inside of the valve body and the insertion cylinder. A resin core is provided, and an adhesive having an insulating property is filled between the inner peripheral surface portion of the outer cylinder and the outer peripheral surface portion of the insertion cylinder facing the outer core surface to fix the outer cylinder and the insertion cylinder. Insulation valve characterized by that. 2. A seal ring having elasticity is interposed between a corner portion of the inner peripheral surface of the outer cylinder and a tip portion of the outer peripheral surface of the insertion cylinder facing the corner portion. Insulation valve.