Mechanical Protection
for Third Party Damage and/or Class location changes
The Solution
- DTP has led major HDPE plates as mechanical protection to minimize the number of leaks and ruptures caused by mechanical damage from equipment and tools.
- DTP provide balanced, safe, accurate advice based on demonstrable competence and unparallel experience to ensure integrity of your assets is maintained.
- Over the last years, DTP has implemented innovative solutions materials and techniques designed to keep costs down and help you to maintain a cost-effective operation and compliance with regulation.
- DTP offers specialized integrity solutions such as the installation of high-density polyethylene (HDPE) mechanical protection to reduce the risk of third-party damage in the class location changes sites.
Activities
- Class location change site evaluation – Pre-engineering.
- Supply and installation of HDPE slabs for mechanical protection.
Remediation (Mechanical Protection) – Encroachment, new infrastructure and/or Construction activities within/near ROW. - Pipe Modification (HDPE Slabbing protective) – Class location change sites.
CASE STUDY
- Client: TC Energy
- Date: 27/07/2023
- Pipeline: Tamazunchale pipeline system, NPS 36
- Location: Tantoyuca Veracruz (274 mts length)
- Scope: Installation of Mechanical Protection (HDPE Slabs) due to a Class location change.
1. Problem statement
TC Energía Class location program identified class location changes, from Class 1 to Class 3 on the Naranjos Tamazunchale gas pipeline in the state of Veracruz.
It was determined in the 2018-2019 evaluation cycle that the class change sites did not meet the class location requirements according to Mexican NOM-007-ASEA-2016, the changes occurred mainly due to increased population density adjacent to the pipeline.
As a result, site-specific hazards were also evaluated and actions were identified to address them in segments outside the class.
The strategy was to apply an innovative mechanical protection to minimize mechanical damage threat and to protect TMZ pipeline form the increase population density and new infrastructure adjacent to its TMZ pipeline.
2. Solution
Install mechanical protection slabs with warning tape on the top of the pipeline along the identified Out Of Class (OOC) segments of the Tamazunchale pipeline to ensure safe operation and the integrity of these pipeline segments.
Mechanical damage was considered the highest potential Hazard on the OCC segments because of potential unauthorized activity on the right-of-way (ROW).
3. Procedure
Excavation and preparation for HDPE Slabs
- Adapt area for temporary access parallel to the pipeline for machinery transit.
- Confirmation of coordinates with topography and marking the work area.
- Carry out the clearing, cleaning of vegetation and removal of Top Soil
Pipe detection and manually carry out surveys (coves) to visually confirm the position and depth of the pipe every 5 m. - Mechanically assisted excavation for placement of HDPE SLABS.
- The approach and leveling of the land must be carried out manually and according to TC Energía procedures, considering slopes of 1:5:1 (H:V).
- The excavation must leave free work area with a minimum average width of 3 meters and variable depth, considering an average cover of 2.30 m along the pipe.
- Excavation at a road crossings must be carried out and covered on the same day.
Slabs intallation and pipeline cover
- Intallation of HDPE SLABS according to the OVERPIPE supplier manual.
- To place the plates (Slabs), it is required to have a distance from the top of the pipe to the plate between 30 cm and 50 cm on average,
- Minimum coverage of the HDPE slabs must be 80 cm.
- Covering and compaction of the pipe must comply with TC Energy specification “TES-CT-COMPC-GL Compaction Control Measures for Pipeline Excavations Specification (CAN-US-MEX)”.
- Carry out the pre-covering of the 30 centimeter plate for the placement of the security tape
- Backfilling of the excavation was using the same material.
- In road crossings, the final covering must comply with one meter deep in layers no greater than 20 cm with subgrade bench material and compacted at ≥ 95%,
- Replace the local Top Soil for recomposition.
