RU2584016C1 - Method by protasov v.n. for anti-corrosion protection of bell and bell - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of internal anti-corrosion insulation with the help of a protective bushing of a bell and bell in pipes and pipe formed pieces with the internal anti-corrosion coating includes placement of support rings of corrosion-resistant version in the inner cavity of the joined bells of the pipe and the pipe formed piece, their pressing along the entire perimeter to the internal collar of the bell and subsequent fixation. Then a protective bushing is inserted into the inner cavity of the joined bell ends of the pipe and the pipe formed piece, and the bushing has elastic sealing rings on its end stepped sections with subsequent closing of these rings in a circular groove, formed during coupling of the outer surface of the end stepped section of the protective bushing with the hole of the support ring with subsequent pressing of elastic sealing rings by approaching end surfaces of the groove with power tightening of welded end surfaces of bells to achieve the required value of the clearance for welding. At the same time they carry out the radially directed deformation of elastic sealing rings towards the inner surface of the bells with provision of tight pressing of elastic sealing rings to this surface and provision of tightness of the gap between the inner surface of the bell and the outer surface of the protective bushing in the area of the welded joint.

EFFECT: increased tightness of a gap in a coupling of outer surface of a protective bushing with inner surface of a bell.

3 cl, 2 dwg

Description

The invention relates to the field of construction, namely, the waterproofing of one-piece butt joints by sealing them, which is carried out during the construction of various objects in construction, for example, metal hollow columns and highways, for example, to prevent pipe corrosion. In particular, it is used for internal anticorrosive insulation of a socket welded joint of pipes and pipe fittings with an internal protective coating while maintaining the bore of the pipeline.

A known method of waterproofing the butt joint of hollow products, in which a layer of sealant or adhesive material is applied to the shell open from opposite ends of at least part of the inner perimeter of at least one of the end sections of the shell, the surface of the middle section can be made a hole for air supply to check the tightness of the connection after heat shrinkage (RF patent No. 2210658, IPC EV04 / 64, publ. 08/20/2003).

The closest known method is Protasov V.N. inner sleeve corrosion protection of the welded joint of the socket ends of pipe fittings with an internal anti-corrosion coating, during the implementation of which welding is performed to the pipe ends with pipe ends with a socket at the free end. Then, a protective anticorrosion coating is applied to the inner surface of each pipe shaped part with a welded branch pipe, a layer of sealant is applied to the inner cavity of the bell in the area adjacent to the inner ledge of the bell. Then, a protective sleeve with sealing rings installed on its end sections and a heat-resistant gasket installed in the middle part of the outer surface of the sleeve in an annular groove is installed in the inner cavity of the connected sockets to prevent overheating of the protective coating during subsequent welding of the connected ends of the sockets. Then the bells are pulled together until the required gap between the connected ends is formed, and they are welded. To control the tightness of the inner sleeve corrosion protection can be further pressure tested with water (RF patent No. 2388961, publ. 10.05.2010).

The disadvantages of this method are the inability to ensure guaranteed quality due to the need to apply sealant when installing the sleeve in route conditions, where it is impossible to provide the required quality control of its preparation, application and curing, as well as the difficulty of ensuring reliable tightness.

The objective of the invention is to increase the tightness of the gap in conjugation of the outer surface of the protective sleeve with the inner surface of the socket to prevent the ingress of aggressive medium into the weld zone.

This is achieved by the fact that in the method of internal anti-corrosion insulation using a protective sleeve of a bell-shaped welded connection of pipes and pipe fittings with an internal anti-corrosion coating, the support rings are placed in the internal cavity of the connected pipe sockets and pipe shaped parts in a corrosion-resistant version, they are pressed around the entire perimeter to the inner collar of the socket and subsequent fastening, then to the inner cavity of the connected socket ends of the pipe and pipe fit of the ith part, a protective sleeve is introduced with elastic sealing rings at its end stepped sections, followed by closure of these rings in the annular groove formed when the outer surface of the end stepped portion of the protective sleeve is mated with the support ring hole, followed by compression of the elastic sealing rings by the converging end faces of the grooves with force compression the welded end surfaces of the sockets to achieve the desired gap for welding, while radially directed deformation of the elastic o-rings towards the inner surface of the sockets with a tight compression of the elastic o-rings to this surface and ensuring the tightness of the gap between the inner surface of the socket and the outer surface of the protective sleeve in the area of the welded joint. At the same time, the support rings can be fixed using glue applied along their entire perimeter and / or along the inner perimeter of each collar of the bell. And they use a protective sleeve, on the outer surface of the middle part of which a groove is made, in which a heat-insulating material is fixed, and the diameter of the inner surface is equal to the corresponding diameter of the connected pipes.

In FIG. 1 shows a diagram of the internal anti-corrosion insulation with the protective sleeve of the socket welded connection of pipes and pipe fittings with an internal anti-corrosion coating;

In FIG. 2 is a view A in FIG. one.

To implement the method, the supporting rings (2) in a corrosion-resistant version are installed, pressed against the inner collar of the socket, and supported by one of the known methods (for example, using glue) in the corrosion-resistant version of the pipe into the inner cavity of the connected pipe sockets and pipe fittings with an internal anti-corrosion coating (Fig. 1) . Then, a protective sleeve (3) in a corrosion-resistant design (for example, steel with a protective coating) is introduced into the internal cavity of the connected socket ends of the pipe and the pipe fittings. On the outer surface of the end stepped sections of the protective sleeve (3) installed elastic sealing rings (4). When the outer surface of the end step portion of the protective sleeve (3), on which the elastic sealing ring (4) is mounted, is coupled with the hole of the support ring (2), the end surfaces of the support ring (2) and the shoulder of the protective sleeve (3) form an annular groove in which the elastic sealing ring (4) is closed. On the outer surface of the middle part of the protective sleeve (3) there is a groove in which the heat-insulating material (5) is fixed, to prevent overheating of the internal anti-corrosion coating of the protective sleeve during welding of the connected ends of the sockets. After installing the protective sleeve (3) in the connected socket ends of the pipe and pipe fittings, the welded end surfaces of the pipes are axially displaced towards each other using a power device to create the necessary clearance between them for subsequent welding. During the tightening of the sockets, the elastic sealing rings are squeezed between the approaching end surfaces of the support rings (2) and the steps of the protective sleeve (3) inside the annular groove formed by them. As a result, directed radial deformation of the elastic sealing rings towards the inner surface of the sockets develops, and the elastic sealing rings are tightly pressed against this surface, which ensures high tightness of the gap between the inner surface of the socket and the outer surface of the protective sleeve to prevent aggressive media from entering the welded joint zone. After compression of the sockets to the required gap between their end surfaces for welding, tack welding of the ends of the connected ends of the sockets is carried out, the power tightening device is removed and welding is performed.

This method was tested in the manufacture of prototypes for socket welded joints of pipes with pipe fittings with a diameter of 159 mm and a wall thickness of 8 mm and an internal anti-corrosion insulation of the welded joint with a protective sleeve having elastic sealing rings on the end stepped sections located in a closed groove formed by end surfaces a support ring fixed in the socket and a ledge of the protective sleeve. After squeezing the sockets to the required gap between their butt mating surfaces for welding and subsequent welding, the gap was sealed between the inner surface of the socket and the outer surface of the sleeve in the weld zone. To do this, in one of the sockets, a hole with a diameter of 4 mm was pre-drilled at a distance of 15 mm from the weld, which serves as an indicator of the tightness of the gap in this zone during subsequent crimping. Pressure testing of the socket connection with water at a pressure of 15 MPa showed that there is no water flow through the hole in the weld zone, both in the initial state and after 100 days of exposure to pressure. Thus, the reliability and quality of the connection is guaranteed.

Claims (3)

1. The method of internal anticorrosion insulation using a protective sleeve of a bell-shaped welded connection of pipes and pipe fittings with an internal anticorrosive coating, including the placement of support rings in the corrosion-resistant version in the inner cavity of the connected pipe sockets and pipe shaped parts, their pressing along the entire perimeter to the inner collar of the socket and subsequent fastening, then a protective sleeve with elas is inserted into the inner cavity of the connected bell-shaped ends of the pipe and the pipe fittings with o-rings at its end stepped portions followed by closure of these rings in an annular groove formed when the outer surface of the end stepped portion of the protective sleeve is mated with the hole of the support ring, followed by compression of the elastic o-rings by the converging end surfaces of the groove when forcefully tightening the welded ends to reach the butt ends the required gap for welding, while radially directed deformation of the electric -particle seal rings toward the inner surface of the sockets secured tightly clamping the elastic seal rings to the surface and providing a gap seal between the inner surface of the socket and the outer surface of the protective sleeve in the zone of the welded joint. 2. The method of internal anti-corrosion insulation according to claim 1, characterized in that the fixing of the support rings is carried out using glue applied along their entire perimeter and / or along the inner perimeter of each collar of the socket. 3. The method of internal anti-corrosion insulation according to claim 1 or 2, characterized in that a protective sleeve is used, on the outer surface of the middle part of which a groove is made, in which heat-insulating material is fixed, and the diameter of the inner surface is equal to the corresponding diameter of the connected pipes.

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