RU2635952C2 - Method of preventing the leaks from flanged joints of the pipelines - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: method of preventing leaks from the flange joints of conduits includes separation and subsequent assembly of the flange connection. Before assembling the flange connection in addition to the primary sealing ring the additional gasket is set, made in the form of a flat ring as well: with holes for the passage of pins that match the location and diameter of the holes for the passage of the studs in the flanges; with a central hole, coinciding in location of the flange connection and the diameter of the core with an outer diameter of the sealing ring; with the interior of the formed center hole and having a cross-section along the entire length of T-shaped. The additional gasket comprises a pin that allows a pressure gauge to monitor pressure in the cavity of the flange connection formed between the gasket and the additional sealing main ring, and liquid hydrocarbons to produce drain accumulated in said cavity.

EFFECT: reduction in labour input to prevent leakage of liquid hydrocarbons from the flange joints of conduits.

2 cl, 2 dwg

Description

The invention relates to methods used to prevent leakage of liquid hydrocarbons from flanged pipe connections, and can be used in the oil, gas and other industries.

In accordance with applicable regulatory and legislative acts, minor leaks from flange connections of pipelines are allowed, which creates risks of emergencies, as well as increased negative impact on the environment.

There is a method of eliminating gas leaks through flange connections of gas pipeline valves during pumping gas through a gas pipeline (see RF patent No. 2208196, publ. 10.07.2003). The method is reduced to filling the wafer gap with a self-vulcanizing sealant introduced through an additional valve under a pressure exceeding the gas pressure in the gas pipeline.

This method is labor intensive, although it does not allow to stop the transportation of gas pumped through the pipeline during its application. However, after applying this method, the complexity of disassembling the flange connection increases significantly due to the bonding of the flanges to each other by means of a self-vulcanizing sealant.

A known adopted as a prototype method for eliminating gas leaks through flange connections of gas pipeline valves (see. Shut-off valves with ball valves manufactured by the plant "TYAZHPROMARMATURA" (USSR) Du50-500 mm. - Gorky: MGP USSR, 1977), which consists in the fact that the flange connection they disconnect, the surfaces of the flanges are polished, the sealing ring or gasket is changed, and the flange connection is reassembled.

This method is also laborious due to the need to polish the surfaces of the flanges.

The objective of the claimed invention is to provide a method for preventing leaks from flange connections of pipelines, which minimizes the leakage of liquid hydrocarbons pumped through the pipeline and, as a result, reduces emissions of pollutants into the environment.

The technical result is a reduction in the complexity of preventing leakage of liquid hydrocarbons from flanged pipe joints in comparison with analogues known to the applicant.

The aforementioned task and technical result in a method for preventing leaks from flange connections of pipelines, including disconnecting and subsequent assembling a flange connection of a pipeline, is accordingly solved and achieved by the fact that before assembling a flange connection of a pipeline, in addition to the main sealing ring, an additional sealing gasket is made in the form of a flat rings as well:

- with holes for the passage of the studs, matching in location and diameter with holes for the passage of the studs in the flanges,

- with a Central hole that matches the location in the flange connection of the pipeline and the diameter of the outer diameter of the main sealing ring,

- with the inner part formed by the Central hole, as well as having a T-shape in cross section along the entire length,

and containing a nipple that allows using a manometer to control the pressure in the cavity of the flange connection of the pipeline formed between the additional sealing gasket and the main sealing ring, as well as drain liquid hydrocarbons accumulated in the specified cavity.

The indicated task and the technical result are respectively solved and achieved also by the fact that the additional sealing gasket is made of technical rubber or soft plastic, or paronite.

The method for preventing leaks from flanged pipe connections is illustrated by graphic materials, where in FIG. 1 schematically shows a flange connection of a pipeline with a cut-out part assembled by the claimed method, and in FIG. 2 shows an additional sealing gasket as such.

A method of preventing leaks from flanged pipe connections, including the separation and subsequent assembly of the pipe flange connection is as follows.

After disassembling the flange connection of the pipeline, flanges 1 and 2, as well as the main sealing ring 3, are cleaned and washed from contamination.

Before assembling the flange connection of the pipeline, in addition to the main sealing ring 3, an additional sealing gasket 4 is installed, made in the form of a flat ring, as well as:

- with holes for the passage of the studs 5, matching in location and diameter with holes for the passage of the studs in the flanges 1 and 2,

- with a Central hole 6, matching the location in the flange connection of the pipeline and the diameter with the outer diameter of the main sealing ring 3,

- with the inner part 7 formed by the Central hole 6, and also having a T-shape in cross section along the entire length.

Moreover, the additional sealing gasket 4 contains a nipple 8, which allows using a manometer to control the pressure in the cavity of the flange connection of the pipeline formed between the additional sealing gasket 4 and the main sealing ring 3, as well as drain the liquid hydrocarbons accumulated in the cavity.

An additional sealing gasket 4 can be made, for example, by gluing three pre-prepared blanks made of technical rubber or soft plastic, or paronite.

The manufacture of additional gasket 4 from technical rubber can also be done by:

- pressing. In this case, a part made of technical rubber is molded in the corresponding molds on hydraulic presses under a pressure of 5-10 MPa, laying the workpiece in the mold and applying the necessary shape to the workpiece under pressure. In the event that the pressing of the preform is carried out in a cold state, the molded product is then subjected to vulcanization. During hot pressing, vulcanization proceeds simultaneously with molding;

- injection molding. In this case, the mold is filled with a preheated plastic raw rubber compound under a pressure of 30-150 MPa. The rubber mixture takes the form corresponding to the working cavity of the form.

In any method, the resulting product is removed from the mold in a cooled state.

For the manufacture of additional sealing gasket 4 by these methods, it is possible to use, for example:

- machine for casting rubber products APAI-200;

- APVR-904 press vulcanizer;

- injection molding machine with a vacuum chamber SJVIM-350;

- Dieffenbacher vulcanizing press.

In addition to the above technical result, the use of the claimed method also reduces corrosion and wear of the main sealing rings at the joints of the flanges by eliminating the effects of atmospheric precipitation on them.

Claims (6)

1. A method of preventing leaks from flange connections of pipelines, including the separation and subsequent assembly of the flange connection, characterized in that before assembling the flange connection, in addition to the main sealing ring, an additional sealing gasket is made in the form of a flat ring, and also: - with holes for the passage of the studs, matching in location and diameter with holes for the passage of the studs in the flanges, - with a Central hole that matches the location in the flange connection and the diameter of the outer diameter of the main sealing ring, - with the inner part formed by the Central hole, as well as having a T-shape in cross section along the entire length, and containing a nipple that allows using a manometer to control the pressure in the cavity of the flange connection formed between the additional sealing gasket and the main sealing ring, as well as drain the liquid hydrocarbons accumulated in the cavity. 2. The method according to p. 1, characterized in that the additional sealing gasket is made of technical rubber or soft plastic or paronite.

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