Why Denso Protal 7200 Continues to Be Specified for Buried and Immersed Pipeline Service
Selecting the right coating system for buried or immersed pipelines is a critical decision that directly affects long-term asset integrity, constructability, and lifecycle cost. Materials and integrity engineers must balance corrosion protection, mechanical durability, temperature performance, and compatibility with cathodic protection systems, often under demanding installation conditions. One coating system that continues to be widely specified across the oil and gas industry is Denso Protal 7200, a 100% solids, high-build liquid epoxy coating.
Denso Protal 7200 application from inside the Custom Coatings International’s Shop in Leduc, Alberta.
Engineered for Compatibility with Cathodic Protection
For buried and immersed pipelines, coating performance under cathodic protection (CP) is one of the most critical acceptance criteria. If a coating disbonds under CP, corrosion risk increases significantly.
When evaluated using ASTM G95 cathodic disbondment testing, Protal 7200 demonstrates low and stable disbondment values across a wide temperature range, including elevated service temperatures up to 95 °C. This performance indicates strong adhesion retention at the steel interface under CP conditions, supporting its suitability as a corrosion protection barrier in long-term pipeline service.
Rather than relying on CP alone, Protal 7200 functions as part of a coating-plus-CP corrosion mitigation system, which is the foundation of modern pipeline integrity design.
Mechanical Durability for Installation and Burial
Pipeline coatings are subjected to significant mechanical stress long before a line is ever placed into service. Transportation, handling, lowering-in, backfilling, and HDD or slip-bore installations all introduce risk.
Protal 7200 demonstrates a balanced mechanical performance profile, including:
High surface hardness (ASTM D2240, Shore D 80+), supporting resistance to indentation and handling damage
Impact resistance of 70.6 in-lbs at 0 °C, indicating strong tolerance to sudden mechanical shock under cold-weather conditions
Abrasion resistance exceeding 1,200 cycles per mil (ASTM D4060), supporting durability against soil interaction and sliding wear
Acceptable gouge resistance under a 40 kg Partech test load, indicating resistance to sharp, localized mechanical damage such as rock contact
Taken together, these properties support reliable coating performance during construction, not just under ideal controlled conditions.
Adhesion Where It Matters Most
Strong adhesion is essential for long-term corrosion protection, particularly at girth welds, tie-ins, and transition zones.
Protal 7200 demonstrates:
High adhesion to abrasive-blasted steel
Strong adhesion compatibility with fusion-bonded epoxy (FBE) systems
This makes it well suited for field joint coating, rehabilitation work, and integration with plant-applied pipeline coatings.
Temperature Flexibility for Real-World Conditions
With a service temperature range from −40 °C to 95 °C, Protal 7200 is capable of supporting a wide range of pipeline operating environments, including those common to Canadian oil and gas infrastructure. Its application temperature range, with appropriate surface preheating when required, also supports year-round construction and maintenance programs.
Proven Performance on Major Pipeline Projects
Denso Protal 7200 has been applied on large-scale pipeline projects across multiple regions and operating environments. Its continued selection is typically driven by constructability, repeatable performance, and compatibility with project specifications rather than novelty. Representative project examples include:
Keystone Pipeline, Canada / United States
On the Keystone Pipeline project, Protal 7200 was used extensively for girth welds, tie-ins, bore joints, and coating repairs. The system supported high daily production rates — reportedly exceeding 150 field joints per day — without the need for heavy or specialized application equipment. Its fast cure characteristics and application efficiency supported construction schedules while maintaining coating continuity and integrity at critical locations.
Source: Denso North America case study
Gas Transmission Pipeline, Malaysia
Protal 7200 was applied on a gas transmission pipeline project in Malacca, Malaysia, where project conditions favored a high-build, single-coat epoxy system with predictable cure behavior. The coating was selected to support efficient field application while meeting mechanical performance requirements under local environmental and construction conditions.
Source: Denso Digest, Vol. 38, No. 3
Victorian Northern Interconnect Expansion (VNIE), Australia
During the Victorian Northern Interconnect Expansion (VNIE) project, Protal 7200 was selected for more than 8,000 field joints over a 36-month construction period, with approximately 60,000 litres of material applied. The scale and duration of the project highlight the system’s suitability for long-term, high-volume field joint coating programs on transmission pipelines.
Source: Denso Digest, Vol. 34, No. 1
A Proven System, Applied with Precision
Performance data alone does not guarantee success. Coating systems only perform as intended when applied correctly and in accordance with project specifications.
At Custom Coatings International, we approach coating application as an engineered process — not just a trade. Our experience with high-performance pipeline coating systems allows us to support owners, EPCs, and contractors with spec-compliant application, quality control, and constructability awareness from project planning through execution.
Closing Thoughts
Denso Protal 7200 continues to be specified because it delivers a well-balanced combination of corrosion protection, mechanical durability, and cathodic protection compatibility. When applied correctly, it supports long-term pipeline integrity in buried and immersed service environments.
As coating technologies evolve, informed system selection and disciplined application remain the foundation of reliable asset protection, a principle that continues to guide our work at Custom Coatings International.
For more information on our Underground Gas Pipe Coating, follow the link below.
