RU2350823C1 - Isolated pipe joint - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: proposed isolated pipe joint comprises pipe sections screwed together, their ends faces being provided with ledges separated by electrically insulating cylindrical elements and elastic seal of the joint. The pipe sections are provided with L-shape lengthwise section nozzles, inside and outside of which two electrically insulating sleeves are arranged with end gaps. Elastomer seal is fitted between the said nozzles faces and surfaces of cylindrical electrically insulating sleeves. The proposed joint comprises also stepwise insulating bush on the joint one end and metal cover on its other end. The screws jointing the pipe section ends are regularly arranged along the circumference screwed in the casing. The metal cover and casing have no rigid coupling with the pipeline.

EFFECT: higher reliability of electrically insulated joint.

1 dwg

Description

The invention relates to the field of engineering and can be used in the manufacture of pipe connection nodes, which are elements of cathodic protection of pipelines from electrochemical corrosion, both general and special, for their underground laying and transition to above-ground sections of pipelines, as well as an insulating pipe connection that excludes ingress voltage to the supply pipe from electrical installations running on gas or other fuel.

For a long time, insulating inserts were created on the basis of a standard flange connection with its corresponding refinement associated with the installation of bushings for bolts and gaskets.

1. Recommendations on the use of insulating flanges on pipelines. - M.: VNIIST, 1968, p.26.

2. The use of insulating flanges on pipelines. V.I. Gladkov, V.G. Kotik, I.P. Gladov, etc. Tr. Institute of VNIIST, 1970, issue 23, pp. 195-207.

Along with the undoubted advantages (low cost, the use of a standard flange and fasteners), this solution to the problem has significant disadvantages, not to mention the complete moral deterioration of the solution as a whole.

At the same time, the very idea of using standard fasteners as part of an electrically insulating structure deserves recognition.

As a prototype of the proposed technical solution, it is advisable to dwell on the development of "MosgazNIIproekt" "Insulating flange connection" A.S. SU 1139926 from 02.15.85.

The connection contains two half flanges with insulating gaskets tightened by bolts, an intermediate element is installed between the gaskets, electrically connected to each of the bolts. The half flanges are equipped with electrical contacts.

It is possible to detect violations of the electrical insulating properties of the flange connection.

The development of MosgazNIIproekt is focused on the traditional use of flanges, which predetermines an increase in size, metal consumption, not excluding the possibility of "shorting" electrical circuits during operation.

The aim of the invention is to provide increased reliability of an electrically insulated connection with relative low cost and orientation on the use of standard fasteners as part of the structure.

The invention is illustrated by the drawing, which shows an insulated pipe connection designed for high pressures.

The insulated pipe connection contains pipe segments 1 and 2, equipped with lugs 3 and 4, having a L-shaped longitudinal section. Two electrically insulating cylindrical bushings 5, 6 are installed inside and outside the tips 3, 4 with end gaps. An elastomeric seal 7 is located between the ends of the L-shaped in the longitudinal section of the tips 3, 4.

As part of the mechanism for connecting the pipes 1 and 2 to each other, a stepped insulating sleeve 8 is used, mounted on the outer surface of the tip 3, and a metal cover 9 on the opposite tip 4, bearing standard fasteners 10 placed evenly on a common circle. In the cylindrical metal case 11, a thickening is made to accommodate the threads.

The gaskets 12 and 13 seal the inner cavity of the insulated pipe connection, and adhesive tape (not shown) is placed on the outer surfaces to seal the joint of parts 9 and 11.

The advantages of the invention are the possibility of using in any transitions from underground gas pipelines of low, medium and high pressure to above-ground, in gas supply systems to the gas control system of the engine of the internal combustion engine in electric generators, ensuring high reliability of electrical insulation and eliminating the occurrence of voltage on the supply pipeline in emergency situations.

The installation of the insulating pipe connection is carried out in the following sequence. Electrically insulating cylindrical bushings 5 and 6 are placed on the outer and inner surfaces of the tips 3, 4, and an elastomeric seal 7 is installed between the ends to be compressed during installation. A step electrically insulating sleeve 8 is mounted on the tip 3, and a cylindrical metal housing 11 is pushed from above.

A metal cover 9 is placed on the tip 4 and all screws 10 are installed. When the screws 10 are tightened, the tips 3 and 4 come closer together, which leads to the compression of the elastomeric seal 7, accompanied by the selection of the corresponding gaps.

After testing the assembled product for leaks and checking the resistance of the electrical circuit between elements 1 and 2, the product is ready for continuous operation.

In the field, the ends of the pipelines 1 and 2 are welded, while the pipe 1 with the tip 4 is electrically isolated from the pipe 2 with the tip 3 due to the elements 8, 5, 6, 7. The internal pressure of the medium is blocked by an elastomeric seal 7 compressed in a closed volume.

When the ambient temperature changes, the insulating pipe connection remains fully operational, which is due to the presence of gaps in the elements 5 and 6 and the coincidence of the total thermal elongation (compression of the elements 9, 11 with relatively small sizes of the sleeve 8).

Compared with the traditional solution to the problem of electrically insulating flanges, an insulated pipe connection is less metal and material intensive.

It consists of relatively simple bodies of revolution, in the manufacture of which the minimum amount of metal is converted into chips.

It also provides the opportunity, based on the results of field tests, to restore the working capacity of the pipe connection by periodically tightening the screws.

Claims (1)

An insulating pipe connection containing segments of pipelines contracted together, equipped with protrusions at the ends, separated by electrically insulating cylindrical elements and an elastic joint seal, pulled together with standard fasteners, characterized in that the pipe segments are equipped with lugs having a L-shaped longitudinal section, inside and outside of which two insulating cylindrical bushings are installed with end gaps, and an elastomeric seal is located between the ends the ends and the surfaces of the insulating cylindrical bushings, while the connection includes a stepped insulating sleeve at one end and a metal cover at the other end, the tightening ends of the piping screws are evenly spaced around the circumference and screwed into the body, and the metal cover and the housing are not rigidly connected to the pipeline .