RU2183783C1 - Method of repair of anticorrosive insulation of subterranean pipe lines - Google Patents

Abstract

FIELD: construction engineering; repair of anticorrosive insulation of subterranean pipe lines. SUBSTANCE: proposed method consists in opening the pipe line, restoration of insulation by means of organic agent at simultaneous forming of filling layer from soil mixed with organic binder. Then, pipe line is covered with cushioning layer of soil mixed with organic binder followed by pouring layer of soil. EFFECT: reduced consumption of labor; enhanced reliability of pipe line. 2 cl

Description

 The invention relates to the field of maintenance and repair of anti-corrosion insulation coatings of underground pipelines.

 To repair the insulation of pipelines, a method of selective repair of the insulation coating of underground pipelines is widely used, including opening the pipeline, monitoring the condition of the insulation and wall, removing old insulation by sections, as necessary, depending on the degree of wear, performing the necessary welding and restoration work, final cleaning of the pipe wall, applying new insulation and backfill of the pipeline. Using this method, insulation repair can be performed without removing the pipeline from the trench and changing the position of the axis of the pipeline (Rashchepkin K.E., Ovchinikov I.S., Suetinova T.D., Belozerov Z.L. Maintenance and repair of the linear part of the main oil and product pipelines . - M .: Nedra, 1969).

However, this method has the following disadvantages:
- a significant proportion of manual labor and low industrialization due to the impossibility of using treatment and insulation machines;
- the probability of breaking the old insulation during opening in areas where the insulation could be suitable for further operation;
- the impossibility of application in areas of short length, in which, due to the natural aging of the material and poor quality of construction work, the insulation has failed and does not provide the required protective potential of the cathodic protection system.

 The closest in technical essence and purpose is the well-known method of repairing insulation, which is carried out as follows (AS 1687993, F 16 L 1/26, BI 40.1991. Method of repairing bitumen and polymer film insulation of an underground pipeline. Mustafin F. M., Rafikov S.K. et al.).

 The backfill soil is developed by a single-bucket or special overburden excavator, it is removed to the dump. The pipeline is lifted using pipe-laying cranes on soft towels so as not to damage the old insulation, which is then sprayed or sprayed (or manually) with a layer of organic matter. Then, at the bottom of the trench, a bulldozer creates a bed of soil with an organic binder. The pipeline is lowered onto the bedding layer and the pipeline is sprinkled with a layer of soil with an organic binder. Then make the final filling of the trench with ordinary soil.

 However, with this method, it is necessary to perform expensive and time-consuming operations to lift the pipeline. When the pipeline rises, additional unforeseen bending stresses arise at the welded joints and possible violations of the old insulation in areas where the insulation could be suitable for further operation.

 The invention solves the technical problem of reducing the complexity and cost of the overhaul process, increasing the service life and improving the operational characteristics of the corrosion protection of underground pipelines.

 This problem is solved by the fact that in the method of repairing corrosion insulation, including opening the pipeline, restoring the protective properties of the insulation coating using organic matter, creating a backfill from the soil layer with an organic binder, sprinkling the pipeline with a soil layer with an organic binder and backfilling with soil, according to the invention, backfilling from a soil layer with an organic binder create simultaneously with the restoration of the protective properties of the insulation coating using organic materials CTBA without lifting the pipe.

 The method is as follows. A rotary overhead excavator with a special working body removes the soil and reveals the entire insulation surface. The pipeline is cleared of the remains of soil. Within the lower half of the pipe section between the insulation surface and the soil base, a gap of 100 ... 200 mm is created depending on the diameter of the pipeline.

 The trailing device, which is moved through the pipeline by the pulling force of a bulldozer, processes the entire surface of the repaired insulating coating with organic material supplied through combs and hoses from a bitumen truck or a mobile tank from a pumping unit. As an organic substance to restore the protective properties of the insulation coating, various cold hardening compositions are used to repair insulation based on phenol-formaldehyde resins, polyurethane resins or high-melting petroleum bitumen.

 In order to increase the service life of the repaired insulation coating, a protective shell is created around the pipeline from bedding and dusting of the pipeline with a layer of soil mixed with an organic binder. To do this, simultaneously with the treatment of old insulation with a special working body of the towing device, soil is mixed with a liquid organic binder and the formation of a part of the protective shell (bedding) located under the pipeline below the side generatrix of the pipe.

 Then, part of the soil from the dump in an amount sufficient to form the upper part of the containment (sprinkling) is mixed with an organic binder and laid on the pipeline with a uniform layer of TR-351 trenchers, equipped with an organic binder application device (set ДС-150). The pipeline is sprinkled with a layer of soil mixed with an organic binder in a ratio of 6. ..15% of the substance by weight of the skeleton of the soil, depending on the type of soil and organic binder, which is used as liquid bitumen, bitumen emulsion, heavy oil refining residues or a special binder for the main TDC pipelines (for example, according to TU 38.101960-83).

 The protective shell is compacted from a soil layer with an organic binder using mounted vibratory plates or special small pneumatic rollers.

 Next, backfilling of the remaining part of the trench with soil and reclamation of the fertile layer is performed.

 The proposed method in comparison with the prototype has the following advantages: low complexity, because repairs are carried out without raising the pipeline; increase the service life of old insulation and can be used in the repair of anti-corrosion insulation coatings of underground pipelines.

Claims (2)

 1. A method of repairing corrosion-resistant insulation of underground pipelines, including opening a pipeline, restoring the protective properties of an insulation coating using organic matter, creating a layer of backfill from the soil with an organic binder, sprinkling the pipeline with a layer of soil with an organic binder, backfilling with a soil layer, characterized in that the backfill from a soil layer with an organic binder create simultaneously with the restoration of the protective properties of the insulation coating with organic matter without lifting the pipe gadfly.  2. A method of repairing the corrosion-resistant insulation of underground pipelines according to claim 1, characterized in that liquid bitumen, bitumen emulsion, heavy oil refining residues or a special binder for BMT trunk pipelines are used as an organic binder (for example, according to TU 38.101960-83).