DUSUP required three solutions for three different types of infrastructure. Having already specified Protal 7200™ for the 24 in. diameter block valves and straight pipe lengths they asked Denso to provide additional systems for the 2 in. diameter connecting valves and pipe tie-ins. Winn & Coales (Denso) Ltd.’s vast experience in corrosion prevention enabled them to provide the following solutions.
System 1 (Epoxy) - For the 24 in. diameter block valves plus straight pipe sections:
The surface was abrasive blast cleaned to a clean near white finish, SSC-SP 10/Nace No 2. An appropriate angular grit was used to achieve an anchor profile (63 to 127 micron). Chlorides were removed to an acceptable level of below 3 micro grams per cm2. A coat of Protal 7200™ was then spray applied over the entire area to a minimum of 508 microns and a maximum of 1270 microns, in accordance with DUSUP’s specification.
System 1: Application of Protal 7200 to block valves.
System 2 (Petrolatum) - For the protection of the 2 in. diameter valves:
After a thorough cleaning of the valve surface removing all dust, dirt and loose matter, a coating of Denso Paste™ was brush applied over the entire area. This was followed by an application of Densyl™ Mastic to fill any voids and irregularities creating a smooth surface for the following tape wrapping. Next a spiral wrap of Densyl™ Petrolatum Tape with a 55% overlap was applied over the valve. A final spiral wrap of Denso PVC Outer Wrap™ with a 55% overlap completed the protection system.
System 2: Denso Petrolatum Tape Wrap System for 2 in. diameter valves.
System 3 (Bitumen) - for the protection of the pipe tie-ins:
After the existing coating was profiled to a 20° angle, all dust and sand contaminates were removed. A brushed coat of Denso Primer D™ was then applied to the pipe area to be protected at a minimum of 150 mm either side of the coating interface and allowed to dry. This was then followed by a spiral wrap by hand or pipe wrapping machine of Densopol 60HT™ Bitumen Tape with a 55% overlap. A final spiral wrap of the Denso PVC Outer Wrap™ was applied by hand or machine with a 55% overlap to complete the protective system.
System 3: Denso Bitumen Tape Wrap System for pipe tie-ins.
Winn & Coales (Denso) Ltd, established in 1883, has been at the forefront of cost-effective, long-term, corrosion prevention, weatherproofing and sealing technology for over 85 years. They have a proven track record of trading in the UAE and have been working with their local agent Bin Moosa & Daly for over 40 years.
Author: Winn & Coales (Denso) Ltd.
Read the article online at: https://www.worldpipelines.com/project-news/29102018/three-types-of-denso-protection-systems-for-gas-pipeline-project-in-dubai-uae/