KR20220068074A - Flange pipe for fluid of high pressure of which leaking test is easy at site - Google Patents

Abstract

Disclosed is a flange pipe for transportation of high-pressure fluid on which a field test can be easily performed. The flange pipe for transportation of high-pressure fluid on which a field test can be easily performed, has a flange attached to the tip of a pipe body. The flange and the pipe body are joined by welding. The joint surface of the flange and the pipe body has a first test fluid groove that travels around the inner diameter of the flange and sealing material grooves formed on both sides thereof at regular intervals with respect to the first test fluid groove. The first test fluid groove has a first test fluid inlet penetrated toward the outer surface of the flange. A hot-melt ring, which is melted and expanded when heat is applied thereto to be fused with the surfaces of the flange and the pipe body, is inserted into the sealing material grooves before the flange and the pipe body are welded. When the flange and the pipe body are welded, the hot-melt ring is melted and expanded by welding heat to be fused with the surfaces of the flange and the pipe body, and a high-pressure test fluid is injected into the first test fluid inlet to test sealing by the hot-melt ring.

Description

Flanged pipe for high-pressure fluid transport with easy on-site testing {FLANGE PIPE FOR FLUID OF HIGH PRESSURE OF WHICH LEAKING TEST IS EASY AT SITE}

The present invention relates to a flange pipe for transporting high-pressure fluid that is easy to test on-site, and more particularly, a joint between the pipe body and the flange of a flange pipe for transporting high-pressure fluid (gas, liquid) having a relatively thicker thickness than a general pipe. A plan for high-pressure fluid transport that can transport 7kgf/cm2 to 120kgf/cm2 of high-pressure fluid without leakage by improving the joint surface of the part and flange, as well as quickly and easily perform on-site pressure and leakage tests immediately after construction It's about the branch.

Crude oil (liquid) pipeline, high-pressure natural gas (gas) pipeline, water supply (liquid) pipeline, etc. Transport pipes that transport fluids (natural gas, gas, liquid, etc.) ranging from 7kgf/cm2 to 120kgf/cm2 are made of steel It is a steel pipe, and thickness is 10 mm or more normally.

A flanged pipe with a flange attached to the end of the pipe is often used for general pipe joints, but the pipe joints of flanged pipes for transporting high pressure fluids are mainly made by welding. In particular, pipe joint welding of crude oil transport pipes or high-pressure gas transport pipes is performed at the transport pipe installation site. After transporting the straight or curved steel pipe to the installation site, the pipe body is cut according to the fluid transport path at the installation site, and the operator connects the cut pipe body by butt welding, corrosion-resistant treatment). After that, a high pressure is applied to the inside of the tube to perform a pressure resistance and leakage test of the welded area. An example of such a pipe joint by welding is disclosed in German Patent DE 10358758A1 and Korean Patent Publication No. 10-2006-0034344.

However, when a flange pipe for transporting a high-pressure fluid having a thickness of 10 mm or more is connected by welding at the installation site, it takes too much manpower and work time required to connect the pipe at the construction site. In addition, in the case of a large transport pipe with a diameter of 1500-2000mm, it can be welded inside the pipe, but the operation is very difficult, and when the diameter is smaller than this, it is difficult to enter the pipe and weld it As a result, there is always the risk of fluid leakage. In addition, it is difficult and time-consuming because both ends of the pipe are sealed and a large amount of high-pressure gas or high-pressure liquid is injected before filling the inside of the pipe with high-pressure gas in order to test the internal pressure and leakage of the welded part.

In general, when connecting flanged pipes, a gasket is interposed between the flange connection surfaces. Examples thereof are disclosed in Korean Patent Application Laid-Open No. 10-2003-0060562, Korean Utility Model Publication No. 20-2008-0003852, or Registered Patent Publication No. 10-1805117. Invention No. 10-2003-0060562, a plurality of bolt holes are formed on the outer peripheral surface of one side of the body, and a flange is integrally formed with one end of the tube on the other body, and a groove is formed on the outer peripheral surface of the flange inlet to provide a watertight packing having a plurality of protrusions. An integrated flange pipe fitted is disclosed, and in Utility Model Publication No. 20-2008-0003852, one pipe body on which a flange is formed and the other pipe body on which a flange is also formed are connected. In the gasket installation structure, a gasket installation structure of a conduit connection part in which a concave groove or annular groove is formed in a flange of one tube body and a protrusion or annular protrusion frame is formed in the gasket is disclosed. Registered Patent Publication No. 10-1805117 relates to a pipeline construction method for high-pressure natural gas transportation using a flanged pipe. The cross-sectional width of the gasket groove is formed to expand toward the inside from the connection surface.

However, these watertight packings or gaskets are inserted between the flanges to be connected when the flange pipes are connected in a solid state preformed by rubber or silicone rubber, etc., and are compressed between the flanges to which the watertight packing or gasket is connected. Keeps leakage, but does not fuse or bond the watertight packing or gasket to the flange face. Therefore, such a watertight packing or gasket is not suitable for a flange pipe for transporting high-pressure fluid. This is because high-pressure fluids (especially high-pressure gases) can leak through between the compression surfaces between the gasket and the flange. In particular, the flange pipe disclosed in Korean Patent Publication No. 10-1805117 welds the flange and the pipe body, and high-pressure fluid may leak through the joint surface of the flange and the pipe body.

In the on-site pressure and leakage test stage, pressure and leakage tests are performed on the joints of flanged pipes. In the withstand pressure test, the test pressure [P70: 103MPa (105kg/cm2), P30: 45MPa (45kg/cm2) P09:15MPa (15kg/cm2)] equivalent to 15 times the maximum working pressure leaks over 5 to 20 minutes or any other abnormalities. In the leak test, the test pressure [P70: 76 MPa (77/㎠), P30: 33 MPa (33 kg/㎠), P09: 099 MPa (99 kg/㎠) equivalent to 11 times the maximum operating pressure is tested, and a certain period of time (12 Time - 24 hours) and check for leaks.

In Registered Patent Publication No. 10-1805117 and Laid-Open Patent Publication No. 10-2014-0015935, an annular tube body is assembled around the flange pipe joint to form a closed space, and then a high pressure of 10kgf/cm2 to 105kgf/cm2 in the closed space After filling the gas, the internal pressure and leakage are checked by the pressure change of the pressure gauge. In FIG. 17 of Korean Patent Publication No. 10-1805117, the bolt is removed, the pressure gauge is fastened, the bolt is removed, and the pressure supply device is connected. In forming an annular tube body, it can be assembled in a circular shape by fastening the bolts around the joint part of the flange pipe in the two-, three-, or four-divided partially curved pipe. At this time, a leakage member such as packing is interposed between the flange pipe and the annular pipe body. However, this test method has the disadvantage that the annular tube body must be separately prepared and assembled, and leakage is easy to occur in the annular tube body itself. In particular, when the diameter of the tube is large, it is very difficult to manufacture the annular tube to maintain airtightness, and to fasten it without leakage of the surrounding body of the joint.

Laid-open Patent Publication No. 10-2003-0060562 (published date: July 16, 2003) Public Utility Model Publication No. 20-2008-0003852 (published date: September 11, 2008) Laid-open Patent Publication No. 10-2014-0015935 (published date: 2014.02.07) Registered Patent Publication No. 10-1805117 (Registration Date: 2017.11.29)

The present invention was made to solve the above-described leakage problem of a flange pipe for transporting high-pressure fluid and the difficulty of field testing, and the first problem to be solved by the present invention is to generate An object of the present invention is to provide a flange pipe for transporting high-pressure fluid that can not only effectively block the leakage of high-pressure fluid, but also easily perform pressure resistance and leakage tests on the joint surface between the pipe body and the flange to be joined at the installation site.

The second problem to be solved by the present invention is not only to effectively block the leakage of high-pressure fluid that may occur at the flange joint surface between the flange pipe and another adjacent flange pipe, but also to test the pressure resistance of the joint surface between the flange pipe to be joined and another flange pipe adjacent to the flange pipe to be joined. and to provide a flange pipe for transporting high-pressure fluid that can easily perform a leak test at an installation site.

The above-described problems of the present invention, in a flange pipe having a flange attached to the tip of the pipe body, but joining the flange and the pipe body by welding, a first test fluid groove circumferentially along the inner diameter of the flange on the joint surface of the flange and the pipe body; A sealing material groove is formed at regular intervals on both sides around the first test fluid groove, and a first test fluid inlet is formed in the first test fluid groove toward the outer surface of the flange, and heat is applied to the sealing material groove. A hot-melt ring that melts and expands and melts to the surface of the flange and tube is inserted before welding the flange and the tube, and when the flange and the tube are welded, the hot-melt ring is melt-expanded by the heat of welding to melt and expand the flange and the tube. This can be solved by making it fusion-bonded to the surface of the tube and injecting a high-pressure test fluid into the first test fluid inlet to test the sealing by the hot-melt ring.

A first flange and a second flange are coupled to both ends of the tube body, and two gasket grooves circumferentially along the joint surface are formed on the joint surface of the first flange coupled to one end of the tube body by spaced apart from each other at regular intervals, and the On the joint surface of the second flange coupled to the other side of the tube body, two protrusions that are inserted into the gasket groove formed in the first flange to make the shape of the gasket are formed, and the joint surface is between the two protrusions of the second flange. forming a second test fluid groove circumferentially along When combined with the 2 flange pipe, the first flange of the first flange pipe is disposed to face the second flange of the second flange pipe, and in a state in which the liquid adhesive is filled in the gasket groove of the first flange, the first flange The first flange of the branch pipe and the second flange of the second flange pipe are bolted together so that the gasket groove and the protrusion coincide with each other, so that a liquid adhesive is compression molded into a solid gasket between the gasket groove and the protrusion, and sealing of the compression molded gasket in this way can be simultaneously tested when the high-pressure test fluid is introduced into the first test fluid inlet.

A rope ring having many internal pores may be inserted into the first test fluid groove and the second test fluid groove by braiding with a plurality of threads.

According to the present invention having the above-described configuration, the hot melt ring melts and expands between the inner diameter of the flange and the outer surface of the tube during welding between the tube and the flange, thereby ensuring the sealing between the inner diameter of the flange and the outer surface of the tube, thereby securing the sealing between the tube and the inner diameter of the flange. Therefore, the possibility of leakage of high-pressure fluid that may occur between the weld bead and the tube body surface or between the weld bead and the inner diameter of the flange due to poor welding is completely blocked by the hot melt ring fused to the tube and the inner diameter of the flange. In addition, since the test fluid inlet is connected to the test fluid groove, and the test fluid groove is formed along the inner diameter of the flange between the two hot melt rings, a fluid (gas or liquid) of the test pressure is put into the test fluid inlet to It is possible to easily test the pressure and leakage between flanges at the installation site.

In addition, when the flange pipe is connected to the adjacent flange pipe, the liquid adhesive is filled between the flange joint surfaces of both sides and solidified in a fused state to become a solid gasket. Therefore, the possibility of leakage of high-pressure fluid at the flange joint surface after flange joining is fundamentally blocked. In addition, since a test fluid groove circumferentially between the two solid gaskets is formed on the joint surface of one flange to be joined, and this test fluid groove is connected to the test fluid inlet, a fluid (gas or liquid) of a test pressure is inserted into the test fluid inlet. In the case of joining two flanges, pressure resistance and leakage tests at the joint surface can be easily performed at the installation site.

In addition, when a rope ring with many internal pores is inserted by braiding into the test fluid groove, it is possible to prevent the hot melt ring from melting and blocking the test fluid groove during welding of the tube body and the flange, and the test pressure Allows fluid to reach without blockage.

1 is a perspective view in which two flanged pipes completed by attaching a flange according to the present invention to a pipe body by welding are continuously arranged before coupling with a bolt and a nut.
Figure 2 is a perspective view showing a state in which the two flange tubes shown in Figure 1 are coupled with a bolt and a nut.
Figure 3 is a view showing the flange coupling surface to face each other by separating the two joined portions of the flange pipe according to the present invention.
4 is a view illustrating a state in which the tube body is welded in a state in which the hot melt ring and the rope ring are inserted into the flange in FIG. 3, with the two flange coupling surfaces facing each other.
5 is a view illustrating a state in which a liquid adhesive is filled in the gasket groove of one flange pipe before the flange joints of both sides are flanged in FIG. 4 .
6 shows a state in which a rope ring is inserted into the test fluid groove between the protrusions of the flange joint on one side in FIG. 5 and the flange joint surfaces of both flange pipes are joined to the flange with a bolt and a nut, and a cock for coupling to the tab of the test fluid inlet. It is shown with bolts.
7 is a view showing the hot melt ring fused between both flanges and the tube body in FIG. 6 and the solid gasket formed between the both flanges and the rope ring inserted into the test fluid groove separated.
8 is a diagram illustrating a method of connecting a high-pressure test fluid supply hose to the test fluid inlet in FIG. 6 and performing pressure resistance and leakage tests.

Hereinafter, with reference to the accompanying drawings, a specific embodiment of the flange pipe for easy high-pressure fluid transport according to the present invention will be described in detail.

As shown in Figures 1 and 2, the flange pipe (100a, 100b) for high-pressure fluid transport according to the present invention is a flange joint using a bolt (b), a washer (y) and a nut (n). A first flange 3a is welded to one end of the tubular body 1a, 1b, and a second flange 3b is welded to the other end of the tubular body 1a, 1b. The first flange 3a of each flange pipe 100a is bolted to the second flange 3b of the adjacent flange pipe 100b. As described above, the flange pipes 100a and 100b for transporting high-pressure fluids according to the present invention are flange pipes having flanges 3a and 3b attached to both ends of the pipe bodies 1a and 1b. Welding is used to join the tubular bodies 1a and 1b and the flanges 3a and 3b.

A feature of the present invention lies in the joint surfaces of the flanges 3a and 3b and the tubular bodies 1a and 1b.

3 and 4, the present invention is a sealing material groove (7a, 7b) circumferentially along the inner diameter of the flange (3a, 3b) on the joint surface of the flange (3a, 3b) and the tube body (1a, 1b) ) to form The sealing material grooves 7a and 7b may have a concave cross-section. In the sealing material grooves 7a and 7b, hot-melt rings 15a and 15b that melt and expand when heat is applied and are fused to the surfaces of the flanges 3a and 3b and the tubular bodies 1a and 1b are attached to the flange ( 3a, 3b) and the tube body 1a, 1b are inserted before welding, and when the flanges 3a, 3b and the tube body 1a, 1b are welded, the hot melt rings 15a and 15b are melted and expanded by the welding heat. Flanges (3a, 3b) and to be fused to the surface of the tube body (1a, 1b). In this way, the present invention is a flange pipe with flanges 3a and 3b attached to the tip of the pipe body 1a, 1b, wherein the flanges 3a, 3b and the pipe body 1a, 1b are joined by welding. By using heat to melt and expand the hot melt rings 15a and 15b between the flanges 3a and 3b and the tube body 1a, 1b, airtightness or watertightness between the flanges 3a, 3b and the tube body 1a, 1b is secured. will do

On the joint surface of the flanges 3a, 3b and the tube body 1a, 1b, a first test fluid groove 29a circumferentially along the inner diameter of the flange and the first test fluid groove 29a at regular intervals on both sides of the center to form two sealing member grooves 7a and 7b. If necessary, a total of four sealing material grooves 7a and 7b may be formed on both sides around the first test fluid groove 29a.

In the first test fluid groove (29a), a first test fluid inlet (31a) that penetrates toward the outer surface of the sleeve of the flange (3a, 3b) is formed to inject a high-pressure test fluid into the first test fluid groove (29a). make it possible A first test fluid outlet 35 may be further formed on the opposite side of the first test fluid inlet 31a of the first test fluid groove 29a. The first test fluid outlet 35 checks whether the high-pressure fluid reaches the entire circumference of the first test fluid groove 29a when the high-pressure test fluid is put into the first test fluid inlet 31a just before the internal pressure and leakage test it is necessary to do A tab 33 is formed at the inlet of the first test fluid outlet 35, and when performing a pressure resistance and leakage test, the cock bolt cb is fastened to the tab 33 and sealed.

The present invention provides a hot-melt ring (15a, 15b) that melts and expands when heat is applied and is fused to the surfaces of the flanges (3a, 3b) and the tube body (1a, 1b) with the flanges (3a, 3b) and Since the tube bodies 1a and 1b are inserted into the sealing material grooves 7a and 7b before welding, the hot melt rings 15a and 15b are heated by welding heat when the flanges 3a and 3b and the tubes 1a and 1b are welded. ) is melt-expanded and fused to the inner diameter of the flanges 3a and 3b and the surfaces of the tubes 1a and 1b. In addition, since the first test fluid groove 29a extends circularly along the inner diameter of the flanges 3a and 3b, a high-pressure test fluid is injected into the first test fluid inlet 31a to seal by the hot melt ring. can be tested

The shape of the hot melt rings 15a and 15b may be formed in a ring shape of a single thickness into which the seal groove is inserted. 7, when the hot melt rings 15a and 15b are separated in a cooled state after melt expansion between the inner diameter of the flanges 3a and 3b and the outer diameter of the tube body 1a, 1b, the flanges 3a, It has a thin cylindrical portion 19 in contact with the inner diameter of 3b) and a groove insertion portion 17 inserted into the groove of the inner diameter of the flanges 3a and 3b. This is because fusion of the hot melt rings 15a and 15b occurs in a large area between the flanges 3a and 3b and the tubes 1a and 1b, and the sealing between the flanges 3a and 3b and the tubes 1a and 1b is that much. means certainty.

The hot melt ring may be molded using one of ethylene-vinyl acetate hot melt resin, polyolefin hot melt resin, styrene block copolymer hot melt resin, polyamide hot melt resin, polyester hot melt resin, or urethane hot melt resin. have.

These hot melt resins include base polymers such as ethylene-vinyl acetate resins, polyolefin resins, styrene block copolymer resins, polyamide resins, polyester resins, or polyurethane resins, tackifying resins, and waxes. (wax), plasticizer, antioxidant and stabilizer, and UV stabilizer are mixed.

The base polymer is an important raw material for forming the basic skeleton by giving rigidity to the adhesive, and since tackifying resins have a low molecular weight, the base polymer with a relatively high molecular weight is used in the product. It plays a role in controlling the physical properties and viscosity, and the wax controls the physical properties of tackifying resins so that the optimum adhesive force can be exhibited for each use condition.

Examples of the resin for the pressure-sensitive adhesive include rosin and derivatives thereof, terpenes and modified terpenes, aliphatic, alicyclic and aromatic resins (C5 aliphatic resin, C9 aromatic resin and C5/C9 aliphatic/aromatic resin), hydrogenated hydrocarbon resins and mixtures thereof; A terpene-phenol resin or the like can be used.

As the wax, microcrystalline wax, fatty amide wax, or oxidized Fischer-Tropsch waxes may be used.

Examples of the plasticizer include benzoates and phthalates such as 1,4-cyclohexane dimethanol dibenzoate, glyceryl tribenzoate or pentaerythritol tetrabenzoate. , paraffin oil, polyisobutylene, chlorinated paraffin, and the like can be used.

As antioxidants and stabilizers, hindered phenols, BHT, phosphites, phosphates, hindered aromatic amines, etc. are added in an amount of less than 1% by mass. They prevent the material from decomposing in the molten state during its service life, during compounding and during application.

Ultraviolet stabilizers are added in a small amount to protect the material from deterioration by ultraviolet rays.

Hot melt resin is "Hot Melt Adhesives｜Technical Issues". pprc.org. Pacific Northwest Pollution Prevention Resource Ctr. Archived from the original on 4 May 2010. Retrieved 4 June 2020" can be used as it is, or it can be molded using commercially available hot melt resins (eg Wukong hot melt).

As described above, the hot melt rings 15a and 15b are interposed between the inner diameter of the flanges 3a and 3b and the surfaces of the tubes 1a and 1b, and the edges of the joint surfaces of the flanges 3a and 3b and the tubes 1a and 1b. In the case of welding, the hot melt rings 15a and 15b melt and expand by the heat of welding, and are fused to the inner diameter of the flange 9 and the surfaces of the tubes 1a and 1b. Through this, the sealing between the tube body and the inner diameter of the flange is ensured. Therefore, the possibility of high-pressure fluid leakage that may occur between the weld bead and the surface of the tube body or between the weld bead and the inner diameter of the flange due to poor welding can be completely blocked by the hot melt rings 15a and 15b fused to the tube and the inner diameter of the flange. .

A rope ring 27a having many internal pores may be inserted into the first test fluid groove 29a by braiding with a plurality of threads. When the rope ring 27a is inserted into the first test fluid groove 29a, the hot melt rings 15a and 15b are introduced into the first test fluid groove 29a in the process of melt expansion, and the first test fluid groove 29a ) to prevent blockage. In addition, it allows the fluid of the test pressure to reach the entire area of the first test fluid groove 27a without clogging. The rope ring 27a is preferably a non-combustible ceramic rope ring made by twisting ceramic yarn. Ceramic rope ring has the advantage of not being damaged by welding heat because the heat resistance temperature reaches 800℃ - 1,200℃. In the case of using the ceramic rope ring, it is possible to completely block the high-pressure test fluid passage by melting the hot melt rings 15a and 15b due to the welding heat during the welding process.

Another feature of the present invention lies in the joint surface between the flanges 3a and 3b.

As shown in Figures 3 and 4, the first flange (3a) and the second flange (3b) are coupled by welding one at both ends of the tube body (1a, 1b), respectively. According to the present invention, the joint surfaces of both flanges 3a and 3b coupled to one tubular body 1a, 1b have different structures. That is, gasket grooves 11a and 11b capable of forming a part of the gasket are formed in the first flange 3a coupled to one end of the tube body 1a, 1b, and on the other side of the tube body 1a, 1b. Protrusions 13a and 13b capable of forming the other part of the gasket are formed on the coupled second flange 3b. The gasket grooves 11a and 11b correspond to a cavity mold used for molding a gasket, and the protrusions 13a and 13b correspond to a core mold used for molding a gasket.

When connecting the high-pressure fluid transport flange pipe (100a, 100b), there is a flange joint, and when the first flange pipe (100a) is coupled with the adjacent second flange pipe (100b), the first flange pipe (100a) ) of the first flange (3a) of the second flange pipe (100b) to face the second flange (3b), and the liquid adhesive (23a, 23b) on the female mold 11 of the first flange (3a) In the filled state, the first flange 3a of the first flange pipe 100a and the second flange 3b of the second flange pipe 100b are connected to the gasket grooves 11a and 11b and the protrusions 13a and 13b. ) to match each other, so that the liquid adhesives 23a and 23b are compression molded into the solid gaskets 25a and 25b_ between the gasket grooves 11a and 11b and the protrusions 13a and 13b. The gaskets 25a and 25b are molded in a state in which they are fused to the surfaces of the gasket grooves 11a and 11b and the protrusions 13a and 13b, so that great airtightness or watertightness can be secured at the flange joint surface.

On the joint surface of the first flange 3a coupled to one end of the tube body 1a, 1b, two gasket grooves 11a and 11b circumferentially along the joint surface are formed at regular intervals and spaced apart from each other, and the tube body 1a , 1b) is inserted into the gasket grooves 11a and 11b formed in the first flange 3a on the joint surface of the second flange 3b coupled to the other side of 1b) to form the shape of the gaskets 25a and 25b. Two (13a, 13b) are formed, and between the two protrusions (13a, 13b) of the second flange (3b), a second test fluid groove (29b) circumferentially along the bonding surface is formed.

A second test fluid inlet 31b connecting the second test fluid groove 29b and the first test fluid inlet 31a is formed in the second flange 3b. A second test fluid outlet 37 may be further formed on the opposite side of the second test fluid inlet 31b. The second test fluid outlet 37 is connected to the first test fluid outlet 35 . The second test fluid outlet 37 confirms that the high-pressure fluid reaches the entire circumference of the second test fluid groove 29b when the high-pressure test fluid is put into the second test fluid inlet 31b immediately before the internal pressure and leakage test. it is necessary to do A tab 33 is formed at the inlet of the first test fluid outlet 35, and when the internal pressure and leakage test is performed, the cock bolt cb is fastened to the tap 33 and sealed, the second test fluid outlet 37 ) is also sealed.

As shown in Figures 5 and 6, when combining the first flange pipe (100a) with the adjacent second flange pipe (100b), the first flange (3a) of the first flange pipe (100a) to the second flange The first flange pipe is arranged to face the second flange 3b of the branch pipe 100b, and the liquid adhesive 23a, 23b is filled in the gasket grooves 11a and 11b of the first flange 3a. The first flange 3a of (100a) and the second flange 3b of the second flange pipe 100b are bolted together so that the gasket grooves 11a and 11b and the protrusions 13a and 13b coincide with each other, and the gasket groove The liquid adhesives 23a and 23b are compression molded into the solid gaskets 25a and 25b between the 11a and 11b and the protrusions 13a and 13b.

The liquid adhesives 23a and 23b are preferably butadiene rubber sealant. In this way, instead of inserting a solid gasket when connecting the flanges (3a, 3b), if the solid gaskets (25a, 25b) are formed between the flange surfaces of both sides using butadiene sealant, when connecting the flanges (3a, 3b) to the flange surface It functions as an adhesive gasket. As shown in Fig. 7, the shape of the gasket is not a regular shape, but a shape to fill the gap between the flanges (3a, 3b) to be connected, and is fused to the surfaces of the flanges (3a, 3b) to form a fluid at the flange joint surface. It completely blocks the risk of leakage.

The sealing of the compression-molded solid gaskets 25a and 25b is performed through the second test fluid inlet 31b when the high pressure test fluid is injected into the first test fluid inlet 31a, and the second test fluid groove 29b. It can be tested simultaneously with the sealing of the hot melt rings 15a and 15b.

A rope ring 27b may be inserted into the second test fluid groove 29b as in the first test fluid groove 29a. When the rope ring 27b is inserted into the second test fluid groove 29b, it is possible to prevent the liquid adhesives 23a and 23b from blocking the second test fluid groove 29b. In addition, it allows the fluid of the test pressure to reach the entire circumference of the second test fluid groove 27b without clogging.

Flanged pipes 100a and 100b according to the present invention having such a configuration are transport pipes for gases such as natural gas and liquids such as petroleum or tap water. 100a, 100b) in-house testing is possible.

Referring to FIG. 8, the test method will be described as follows. The test is conducted after the butadiene rubber sealant is cured (about 1 day).

1) Remove the cock bolt (cb) from the first test fluid outlet (35) at the lower end to open the first test fluid outlet (35).

2) Connect the high-pressure fluid (gas, liquid) pump to the main hose (H), and connect the branch hoses (h1, h2) to the first test fluid inlet (31a) of the joined flanges (3a, 3b) on both sides Check whether the test fluid (gas, liquid) is discharged from the first test fluid outlet (35).

3) Tighten the cock bolt (cb) of the first test fluid outlet 35 and proceed with the pressure test and leakage test. Teflon sealing tape is wound around the cock bolt cb fastened to the first test fluid outlet 35 to prevent leakage by pressure.

4) At this time, the pressure resistance test and the leakage test of the butadiene sealant between the flange 3a and the flange 3b are also performed in parallel.

5) The maximum test pressure is 150kgf/cm2.

6) After completion of the pressure test and leakage test of the fluid (gas, liquid), remove the cock bolt (cb) from the first test fluid outlet 35 at the lower end, and after removing all the fluids (gas, liquid), the first test fluid outlet (35) The sealing body is injected and occluded. After removing the hose, the test is completed by fastening the cock bolt (cb) to the first test fluid outlet (35). Also at this time, Teflon sealing tape is wound around the cock bolt cb to prevent fluid leakage.

1a, 1b: tube body
3a, 3b: flange
5: bolt ball
7a, 7b: sealing material groove
9: Flange inner diameter
11a, 11b: gasket groove
13a, 13b: protrusions
15a, 15b: hot melt ring
17: groove insertion part
19: cylindrical part
21a, 21b: weld bead
23a, 23b: liquid adhesive
25a, 25b: solid gasket
27a, 27b: rope ring
29a, 29b: test fluid groove
31a, 31b: test fluid inlet
33 : tab
35: first test fluid outlet
37: second test fluid outlet

Claims (3)

In a flanged pipe with a flange attached to the tip of the pipe,
The flange and the tube body are joined by welding,
A first test fluid groove circumscribing along the inner diameter of the flange and a sealing material groove are formed on the joint surface of the flange and the tube body at regular intervals on both sides around the first test fluid groove, and the first test fluid groove has an outer surface of the flange By forming a first test fluid inlet that penetrates toward , When welding the flange and the tube, the hot melt ring is melted and expanded by the heat of welding to be fused to the surface of the flange and the tube, and a high-pressure test fluid is introduced into the first test fluid inlet to test the sealing by the hot melt ring. Flanged pipe for easy high-pressure fluid transport, characterized in that it allows for field testing.
According to claim 1,
A first flange and a second flange are coupled to both ends of the tubular body,
On the joint surface of the first flange coupled to one end of the tube body, two gasket grooves circumferentially along the joint surface are formed at regular intervals, and on the joint surface of the second flange coupled to the other side of the tube body, the first Two protrusions that are inserted into the gasket grooves formed in the flange to form the shape of the gasket are formed, and between the two protrusions of the second flange, a second test fluid groove circumferentially along the joint surface is formed, and the second A second test fluid inlet connecting the second test fluid groove and the first test fluid inlet is formed on the flange,
When the first flange pipe is combined with the adjacent second flange pipe, the first flange of the first flange pipe is arranged to face the second flange of the second flange pipe, and the liquid adhesive is filled in the gasket groove of the first flange. In one state, the first flange of the first flange pipe and the second flange of the second flange pipe are bolted together so that the gasket groove and the protrusion coincide with each other so that the liquid adhesive is compression molded into a solid gasket between the gasket groove and the protrusion, A flange pipe for easy on-site testing, characterized in that the sealing of the compression-molded gasket can be tested at the same time when the high-pressure test fluid is introduced into the first test fluid inlet.
3. The method of claim 1 or 2,
A flange pipe for easy on-site testing of high-pressure fluid, characterized in that a rope ring having many internal pores is inserted into the first test fluid groove and the second test fluid groove by braiding several threads of thread.

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