3 Introductory part

3.1 Basis for technical diagnostics:

Pilot test program for the Method of infrasound monitoring of the dynamic characteristics of pipelines of JSC XXX at the facilities of LLC XXX dated 00.00.0000. Appendix 3.1.

3.2 Information about the Customer

Name of organization: LLC “ХХХ” Legal address: 000000, Region, City, street, building Postal address: 000000, Region, City, street, house

3.3 Integral diagnostic method

Technical diagnostics were carried out using the method of integral and element-by-element assessment: - power factors; - stress-strain state; - residual resource; - terms of safe operation of pipelines using instruments for infrasound monitoring of the dynamic characteristics of pipelines - hereinafter referred to as the Integral method.

3.4 Purpose of the integral method

The purpose of the Integral method is to ensure reliable operation at the required technological conditions and reduce the costs of maintaining the proper technical condition of the pipeline. Subgoals of using the Integral method: 1. assessment of the actual technical condition of pipelines; 2. search and determination of pipeline faults; 3. development of recommendations to ensure the reliability of safe operation of pipelines under actual conditions.

3.5 Problems of the integral method

  1. Determination of strength, durability (residual life) and reliability (terms of safe operation and deadlines for troubleshooting) of the pipeline and its elements.
  2. Identification of malfunctions (deviations, defects, damages) at early stages of development, prevention of their escalation, identification of causes.
  3. Reducing operating costs due to the transition from emergency repairs to preventative ones.
  4. Reducing the number of failures (accidents/leakages) due to their prevention.
  5. Addition and clarification of the assessment of technical condition, taking into account the results of diagnostic examinations carried out by other methods.
  6. Integration and more complete use of information available to the Customer for ranking pipeline faults.
  7. Optimization of diagnostic examination programs by reducing the volume of activities while simultaneously increasing efficiency.
  8. Reducing the volume of repair and restoration work and increasing cost efficiency through the use of selective measures to ensure reliability of operation in established modes and operational safety.

3.6 Main stages (general scheme) of work within the framework of the integral method

3.6.1 Stage 1. Data analysis

Analysis of data from design, executive and operational documentation, engineering survey materials, results of certification, diagnostic examinations and surveys. The list of studied technical documentation for the selected pipeline section includes:

  1. Project documentation:
  • Total information;
  • plan, profile;
  • specifications of pipes, connecting parts, shut-off and control valves.
  1. As-built documentation:
  • working drawings;
  • certificates for installed pipes, connecting parts, shut-off and control valves.
  1. Operating documentation:

3.1. data on technological modes of pipelines:

  • pressure (input/outlet);
  • temperature (input/output);
  • data on failures (accidents/leaks) and repairs for the entire period from the start of operation.

3.6.2 Stage 2. Building a mathematical model

Based on the results of stage 1, a database of pipeline elements (pipes, connecting parts, welded joints, structural elements, etc.) is formed. This database serves as the basis for constructing a spatial model (digital model) of the pipeline.

3.6.3 Stage 3. Additional instrumental infrasound monitoring of the dynamic characteristics and parameters of the pipeline, actual loads and external influences

At this stage, infrasonic monitoring of above-ground sections of process pipelines is carried out, which is carried out using infrasonic monitoring devices. Using infrasound monitoring devices, linear accelerations and angular velocities are recorded in three directions. Based on the recorded data, the amplitude-frequency characteristics of vibrations are determined: displacements and angles of rotation of the pipeline at the installation sites of the device.

3.6.4 Stage 4. Solving a set of dynamic problems

At this stage, a set of dynamic problems on the distribution of displacements and forces arising in pipeline elements is solved; calculation of the dynamic stress-strain state, including in zones of increased stress concentration caused by both design features (turns and branches of the pipeline, supports, welded joints, etc.) and defects (corrosion damage, cracks, defects in welds etc.) identified during previous examinations