BASF’s Masterseal and Mastertop epoxy systems offer a complete, flexible and cost effective solution for protection of the STP structure in the highly corrosive environment.
BASF Construction Chemicals recently launched its Sewerage, Oil & Gas, and Industrial Coatings (SOGIC) range into UAE markets and the response has been tremendous. The first valuable recognition of the range’s superior capabilities has come with the awarding of an important supply contract for the new AED 227 million Al Saja’a Sewage Treatment Plant (STP). This contract was won against stiff competition from entrenched market players.
The Al Saja'a Sewage Treatment Plant (STP) project comprises four phases, each of which will treat 15,000 m3 per day, bringing the total capacity of the plant to 60,000 m3 per day. The first and second phase will see the design and building of the initial tanker discharge facilities and the sewage treatment plant. The 40-bay tanker discharge facility (TDF) will have the capacity to handle 60,000 m3 meters per day of sewage, and the STP Phase 1 and Phase 2 which is under construction will treat 30,000 m3 of sewage per day. Phase 3 and Phase 4 are scheduled for 2011.
Explains David Manuel, Business Segment Manager for the SOGIC range at BASF: “Across the UAE, projects relating to STP currently total in excess of USD2.8 billion. Saudi Arabia alone has announced a USD17 billion initiative to improve its STP and Waste Water Treatment Plants (WWTP) over the next five years. The great demands for STP and WWTP across the Middle East can be attributed to a number of factors: the large influx of expatriates into the region and the subsequent population expansion; the deterioration of old STPs and WWTPs; and the limited capacity of the existing treatments plants.
Durability is a primary requirement in the construction of any new infrastructure. “A key challenge in the development of any STP facility is protecting the steel and concrete structures from the corrosive environment – i.e., the effects of biogenic corrosion as well as the corrosion prevalent in hydrogen sulphide environments,” says Manuel: “On the Al Saja’a project, consultants Halcrow thus put stringent specifications in place for protection of all concrete faces of structures in direct contact with sewage, including floors and walls.”
The requirements were for the use of a 3mm Polyurethane lining (Dura thane 100EA), 6mm GRP in situ lamination and normal epoxy coatings of various thicknesses (1mm and 500 microns) in specific areas, with anti-slip in wet areas. Epoxy floor coatings and specialised external wall finishes were also specified.
Notes Manuel: “BASF Construction Chemicals was able to offer a complete system from its range - including primer, filler and topcoat – a solutions that surpassed the functional requirements of the specification, offered flexibility and met the tight budgetary constraints of the project.”
BASF’s SOGIC solution:
Masterseal BC 1820 system – an Amine-cured Epoxy Novolac system, this is a non- toxic highly cross-linked 100% solids epoxy coating with exceptional chemical resistance and cures even at 0oC. It is widely used as a lining system to protect concrete and steel in the waste water treatment and petrochemical industries. It is typically used for the internal protection of concrete or metal tanks containing aggressive chemicals, oils, acids, solvents and alkalis.
Masterseal SP 120 PF – an Amine-cured pitch free epoxy, it is a solvent-free, highly chemical resistant non-carcinogenic coating. It is smooth and glossy in appearance, and provides a heavy duty protective, waterproof and flexible coating. It is widely used in the sewerage and waste water industry as well as other aggressive immersion conditions on cementitious and metal substrates. Uses include the lining of tanks, pipes and ducting, coating concrete, asbestos cement, steel pipes and non ferrous metals.
Mastertop 1205 - a pigmented, solvent-free, high-build epoxy floor coating system designed to offer seamless, durable floor protection at applied thicknesses between 0.2mm to 0.50mm. With the addition of slip resistant aggregates between coats, anti-slip resistant applications can be achieved in system build-up thicknesses between 0.50mm to 2.0mm. It exhibits excellent wear, abrasion and chemical resistance and provides impermeable protection against common oils, greases and lubricants.
Says Manuel: “An important part of our success is the fact that we go out of our way to understand project requirements and provide correct and innovative product recommendations that are comprehensive and complete. Our aim is to not only meet engineering requirements but add value, increasing the lifespan of structures and lowering maintenance costs.”
The products offered from the BASF SOGIC provided exactly that. “The contactor wanted a concrete protection system for sewage conditions, offering high chemical resistance towards hydrogen sulphide and sulphuric acid,” explains Manuel. “Masterseal 1820 offers long term resistance to 98% sulphuric acid under immersion conditions. It’s a fast setting GRP lining system with very high impermeability (osmosis resistance), unlike normal unsaturated polyester GRP systems. It also offers superior chemical resistance over polyesters, vinyl esters and our competitor’s Novolac systems.
“The Masterseal SP 120 PF is also highly chemical resistant. This heavy duty, waterproof coating can be used in aggressive immersed conditions on cementitious and metal substrates, and also has excellent abrasion and flexibility.”
BASF innovation delivers added value
There were a number of challenges that needed to be addressed. Says Monish Ramchandani, Key Account Manager, BASF : “The budget for this project was very tight, so the contractor had considered the use of normal epoxy systems rather than Novolac epoxy systems. BASF, after several technical meetings with the consultant and contractor to understand the job requirement, was able to offer a tailor made solution that not only met specifications but innovated upon requirements to add value to the project. On the strength of this solution we won this contract even though our competitors offered more economical systems as per the specification.”
Says Ma’nuel: “The Masterseal 1800 series is a multifunctional Phenol Novolac Epoxy (PNE) resin that was specially designed by BASF’s Dubai Development Team in collaboration with our epoxy manufacturer. This resin is supplied solely to BASF Dubai under an R&D agreement. It is then cross-linked with a special amine hardener thermogenic technology developed in-house to obtain a highly cross-linked matrix that is non-hazardous and has curing capability even at 0oC, offering a return to service within 24 hours and, in some cases, within four hours.
“The cured matrix provides superior chemical resistance to a wide range of concentrated chemicals, heat resistance, mechanical properties and osmosis stability. Tests conducted internally and externally showed that the cured matrix of MASTERSEAL 1820 had a surface corrosion of only 3.0% after 270 days of continuous immersion in 98% sulfuric acid at 25oC; and 4.5% surface corrosion after continuous immersion in 98% sulfuric acid at 70oC for 100 days.”
Throughout the project, BASF did routine inspection, supervision, consultation and testing of all solutions with regard to, for example, bond strength and pull–off, as per site requirements. It also provided training to contractor EMCON on all the approved systems.
Concludes Ramchandani: “All the parties – the client, consultant and the contractor - appreciated our inputs and the additional value our products offered.”
The project will be completed in December 2010.