Introduction
The GCC is home to some of the world’s most challenging climate conditions for pipelines and pipe system solutions. Harsh weather conditions – onshore and off – present an added layer of complexity to pipe material selection. In this article, we will cover the main factors to consider when choosing pipe system materials suitable for these harsh conditions. This is based on Gerab’s field experience over 45 years and covers applications across oil & gas, power & desalination, industry & manufacturing, HVAC and district cooling, food and process industries, as well as special environments such as marine and offshore.
Weather conditions in the GCC are primarily arid desert, and the waters of the Arabian Gulf are recognized for their high salinity and temperature. Temperatures on land can exceed 50 degrees Celcius, and in the UAE, for example, average temperatures last year in the UAE surpassed 32 degrees. Temperatures in Saudi Arabia have also seen drops to -4 degrees C, exasperating the external temperature ranges that pipe systems have to operate in. This can cause severe thermal contraction and expansion issues, may need to consider UV exposure, and directly affect the type of pipe material to use. This is further exasperated by the abrasion from salt and sand, as well as the impact of high humidity and its role in accelerating material degradation.
Application and Function
The initial guiding parameters for pipe material selection start with the application at hand. The type of liquid or gas that the pipe system has to handle will set the initial parameters that the pipe material has to accommodate. In addition to the pressure requirements, corrosion, abrasion, and thermal resistance have to be accounted for. Where carbon steel and metal pipe materials are ideally suited for handling high-pressure applications for non-corrosive materials such as gas, nitrogen, and lube oil, more corrosive liquids such as acids or peroxide will require pipe materials that can handle these corrosive materials. Chemical manufacturing and handling will require different materials or coatings to be able to withstand these chemicals.
Marine and offshore applications exert more thermal, abrasion, and corrosion considerations, and are often restricted by size and weight constraints. Space on offshore oil rigs or marine vessels is scarce, and the weight of the pipe system material will need to be considered. Here, more exotic alloys are usually relied on to achieve the same temperature and pressure capabilities while using lighter or smaller pipes. Maintenance and longevity considerations are also more pronounced in marine and offshore applications and are a critical factor to consider especially in areas where inspection, maintenance, repair, or replacement of a pipe system or section is prohibitive, expensive, or may result in operational shutdowns.
Pipe Materials
The pipe system materials available for handling these applications and functions in the harsh environmental conditions of the gulf are varied, with the most relied on being:
- Cast iron: One of the earliest materials used for piping, it is most commonly used in underground applications. Underground pipes for water, gas, and sewage have to be durable, pressure-resistant, and long-lasting, as they are generally placed underground for several decades without having to be replaced.
- Steel and steel alloys: Steel is the workhorse for most industrial applications because of its ability to manage fluids under high pressure. The most common types of steel piping materials for manufacturing facilities are carbon steel, ideally suited for indoor systems carrying non-corrosive materials; and galvanized steel, which is better suited for handling corrosive fluids, as well as high-temperature materials. However, it is not as ideal for high-pressure substances, as it is rated only for pressures of up to 250 psi.
- Non-ferrous: Several types are available including brass, aluminum (several types based on the alloy added to the aluminum – for transporting highly corrosive or high-pressure materials), copper (used in commercial and residential water applications), copper-nickel (most commonly used in marine and offshore applications for its excellent ability to high temperatures and transport seawater effectively), and concrete (primarily for civil applications.)
- Plastic: A wide range is available here including PVC, polypropylene, polyethylene, PEX, and ABS. Plastic pipes are ideal for handling corrosion, and the different types are versatile, allowing for use across civil, municipal, and industrial applications.
Additional Considerations
Pipe systems do not work in isolation. They are an integral part of a greater operation and one needs to consider how they are attached to broader systems. Material limitations on pipes are more pronounced where fittings are concerned, and the types of valves or fittings they connect to need to be considered when reaching higher diameters, pressures, and temperatures. A system is as strong as its weakest link, and joints and connections are areas that may impose limitations on the choice of materials for your pipe system solution. These also join different systems made up of different materials, and compatibility issues may arise.
The overall service life and maintenance requirements are additional critical points to consider. Access to the pipe system to conduct preventive, routine, or emergency maintenance and cleaning will have a bearing on the pipe materials chosen. In addition, with growing concern for the environment, planning for decommissioning and recycling are generally included in the initial design phases of the piping system, and proper removal and disposal of systems can have added considerations on the final cost of a complete pipe system solution.
Finally, there is a wide range of options that you can fall back on in lining and coating. These can be instrumental for adapting pipes and fittings to specific environments, or for handling additional operational considerations. Thermoplastic-lined pipes, for example, include Polyvinylidene Fluoride (PVDF), Fluoropolymer (PTFE), and Polypropylene (PP). These can provide additional protection to pipes when transporting liquids from low chemical makeup through high-strength acids and other corrosive liquids.
Conclusion
Piping systems for critical infrastructure projects and megaprojects are complex, and the applications involved demand impeccable quality that conforms to international standards, allowing for systems to operate efficiently and interact with their environment. Environmental considerations vary, and in the GCC, often exert additional stresses that a pipe system has to contend with. International standards such as ASTM, API, and ISO, as well as regional and local regulations are designed to give further guidelines for pipe system material selection.
Given the parameters involved in the selection of pipe system materials, a great deal of cooperation is necessary between all stakeholders to agree on the optimum pipe system material to use. Field experience across all the considerations further contributes to ensuring the selection of the right pipe system material meets safety and operational demands and is not over-designed so it remains economical and cost-efficient.
At Gerab, we recognize this and take an active part in supporting clients throughout their planning process to share experiences, align with best practices, and deliver to uncompromising standards. Our experience and expertise in the region make us the perfect partner for sourcing the right materials for the right climate in whatever application your project needs.
To partner with Gerab for your next project, contact us today