Materials Performance Supplements

TANK 2018

Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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5 TANK CORROSION CONTROL SUPPLEMENT TO MP MATERIALS PERFORMANCE MAY 2018 nation and also lead to blistering and peel- ing of the coating. Based on the experience at the Wafra Oilfield , C S was deemed an unsuitable material for construction of the bulk chem- ical facility as it led to excessive mainte- nance, operational disturbance, frequent leaks and unnecessary loss of chemicals, and environmental damage. Generally, the authors say, materials selection for any project requires careful review, testing, and control so all materials can be stipulated as "fit-for-purpose" when used in chemical service. In the review, they recommend a material compatibility proto- col that consists of two stages: laboratory testing for material compatibility con- ducted per NACE/ASTM TM0169 G0031 12A, 2 and field experience documentation. Th e laborator y t est conditions should mimic the field application parameters (temperature, pressure, environment, etc.). Based on the laboratory results, technically unacceptable materials should be rejected a n d t e c h n i c a l ly a c c e p t a b l e m a t e r i a l s should undergo a cost review. Although the most economical material can be selected, the limitation with this approach is that the lowest-cost materials are not always the most economical over the field life of the component (i.e., small savings at the proj- ect stage can lead to high costs during the operational stage). In terms of appropriate field ser vice materials, Type 316 (UNS S31600) stainless steel (SS) as a material for integrity chemi- cals, which has a broader range of resis- tance to neat chemicals than CS, was suc- cessfully used at the Wafra Oil Field bulk chemical handling facility. All the chemical injection systems in the facility use Type 316 SS quills, which were found to be in sat- isfactory condition. Additionally, produc- tion and integrity chemicals—specifically, the potential use of aromatic solvents, amines, acids, and alkalis—should also be actively considered when selecting elasto- meric seals. The best qualification for any seal or seal material is the behavior of actual working seals exposed to the chemi- cals under field conditions. Because of the experience with CS, two additional ch emical storage tank s and associated piping installed at the bulk chemical handling facility were constructed with Type 316 and Type 316L (UNS S31603) SS. Individual manifolds for the tanks were installed to avoid mixing the chemicals. Based on the chemical manufacturers' rec- ommendations, the elastomer pump seal material chosen was ASTM D1418, 3 class FFKM grade (perfluoroelastomers), which is compatible with the integrity chemicals used and found to be more corrosion resis- tant against aggressive amines. After 18 months in service, no leaks in the new tanks or piping were noticed. A field inspection of an opened inlet line of piping spool for both tanks detected no signs of corrosion. When determining the most cost-effec- tive materials for a construction project, the authors conclude that it is imperative to carefully consider the use of corrosion- resistant alloys as viable materials alterna- tives to reduce corrosion problems, which in turn increases operational reliability while lowering maintenance costs. Additional information on the case study can be found in CORROSION 2017 paper no. 8967, "Case History on the Selec- tion of Materials in a Bulk Handling Chem- ical Facility at Partitioned Zone (Kingdom of S audi Arabi a and Kuwait)— A Case Study." References 1 T. Kamshad , A/R . Al-Ghamdi , R .S. Siriki , M. Sabesan, "Case History on the Selection of Materials in a Bulk Handling Chemical Facility at Partitioned Zone (Kingdom of Saudi Arabia and Kuwait)—A Case Study," CORROSION 2017 paper no. 8967 (Houston, TX: NACE International, 2017). 2 NACE/ASTM TM0169 G0031 12A, "Standard Guide for Laboratory Immersion Corrosion Testing of Metals" (Houston, TX: NACE, 2012). 3 ASTM D1418–17, " Standard P ractice for Rubber and Rubber Latices—Nomenclature" (West Conshohocken, PA: ASTM, 2017). Chemical leaked at the welding joint on the tank sampling point. Chemical spillage around the periphery of the tank.

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