RU2016337C1 - Apparatus for pressing sleeves into inner surface of tubes - Google Patents

Abstract

FIELD: pipeline coupling systems. SUBSTANCE: apparatus has a cylindrical vessel, filled by a liquid, and means for freezing the liquid. A body of the vessel, made of elastic material, is provided by a rod, placed inside of the vessel and having discs, secured to its end portions. EFFECT: enhanced reliability of pressed-in sleeves. 1 cl, 2 dwg

Description

 The invention relates to the pumping of liquids and can be used in the installation of pipelines.

 Currently, to protect the inner surface of pipes, they are coated with various materials (enamel, glass, cement, plastics, metals).

 When welding pipes, the coating material in the area adjacent to the joint burns out completely or partially and ceases to protect the inner surface of the pipes.

 Currently, to insulate the inner surface of the joints, coating is applied by spraying insulating materials, spreading them using special mandrels. Polyethylene pipes are introduced into the steel pipes with their subsequent distribution.

 To distribute the polyethylene pipe, hot water is injected into the internal cavity and a vacuum is created in the annular space between the steel and polyethylene pipes.

 Known methods of distributing the inner tubes in the shells of heat exchangers by rolling by rolling, bushings in the housings by durning and rolling.

 The prototype of the proposed device is a device for distributing bushings in the hole of a thick-walled plate. This device is a cylindrical mandrel with an axial channel. On part of the length there is an annular groove communicating with the axial channel by radial drilling. The sleeve, which must be distributed in the plate, fits tightly on the part where there is a groove.

 This device, called the "ice syringe", works as follows.

 The mandrel with the sleeve installed is inserted into the hole of the plate. Through the central channel, water is supplied into the annular groove. By supplying a refrigerant, water is first frozen in the lower and upper parts of the mandrel, then in the annular groove. When working with this "ice syringe", you must first freeze water in the upper and lower parts, creating ice plugs, and only then in the annular groove. Due to the high thermal conductivity of the mandrel metal, it is difficult to achieve such a freezing sequence. To do this, you either need to make the mandrel long enough or provide a coolant supply first to the upper and lower parts of the mandrel, and then to the middle part with a groove.

 To do this, you must have free access to the upper and lower parts of the mandrel located on opposite sides of the fastened parts. To distribute the bushings at the pipe joints, located at a sufficient distance from the open end of the pipe, freezing of water in the sections in the axial channel of the mandrel is not possible when supplying refrigerant from the outside.

 In this case, first the water freezes in the annular groove and the main expansion of ice occurs in the axial direction between the sleeve and the mandrel. When transferring cold from the outer layers to the inner, freezing occurs in the same direction. In this case, the ice, expanding, displaces water through radial drilling into the axial channel. The volume of ice in the annular groove is negligible and therefore the radial deformation of the sleeve is insignificant, which, in turn, leads to a weak landing of the sleeve.

 The purpose of the invention is an increase in the fit of the sleeve.

 This goal is achieved by the fact that a corrosion-resistant sleeve made of stainless metal is introduced into the internal cavity in the joint zone. A cylindrical vessel is introduced into the bore of the sleeve, the end walls of which, made along the inner diameter of the sleeve, are rigidly interconnected along the axis, and the side surface is made of elastic deformable material. After welding the pipes, the water in the vessel is frozen. When freezing, the water, expanding in volume, presses through the walls of the vessel against the walls of the sleeve and, plastically deforming it, presses it to the pipe. A rigid connection between the end walls of the vessel prevents its expansion in the axial direction and the deformation proceeds in the radial direction. In this case, the plastic deformation of the sleeve occurs, and it is tightly pressed against the walls of the pipe. After that, the ice is melted in the vessel and, creating pressure in the pipe, the vessel is pushed through the open end of the pipe.

 In FIG. 1 shows a General view of the proposed device; figure 2 is a diagram explaining the operation of the device.

 The device consists of a polyethylene vessel 1 with a conical bottom, an axial expansion limiter 2 installed therein, a threaded cap 3 with a conical bottom. Before installation, water is poured into the vessel into the vessel.

 A corrosion-resistant sleeve 3 is installed in the hole of the pipe 1 before joining the pipe 2. A vessel of water 4 is installed in the hole of the sleeve 4 and frozen. In this case, the sleeve, plastically deformed, is pressed against the protective inner layer 5. After this, the water in the vessel is thawed, creating pressure in the pipe, the vessel is removed from the side of the open end of the pipe. The vessel has a conical bottom and a lid and also the conical ends of the axial expansion limiter. This is done so that when the vessel is pushed out, it does not jam, due to the stop on the end.

 Using the proposed device provides, in comparison with existing, the following advantages: reducing the complexity of installing pipelines in the field; reliable isolation of the junction from the aggressive influence of the pumped medium.

Claims (1)

 DEVICE FOR PRESSING BUSHING INTO INSIDE SURFACE OF PIPES, made in the form of a cylindrical vessel filled with liquid, and means for freezing the liquid, characterized in that the vessel body is made of elastic material and equipped with a rod placed inside it with disks fixed to its ends.

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