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.

Issue link:

Contents of this Issue


Page 29 of 31

30 MAY 2018 W W W.MATERIALSPERFORMANCE.COM TANK CORROSION CONTROL SUPPLEMENT TO MP Corrosion Basics Tank and Containment Linings Some of the most critical uses of protec- tive coatings involve ser vice conditions that require the use of coatings as linings. They may be the same coatings that are used in atmospheric or underground ser- vice, but they are usually specially formu- lated for three specific purposes: 1) To protect the substrate (steel, alu- minum, concrete, or other materials) from attack by the liquid being stored inside the tank or temporarily stored inside a contain- ment structure 2) To protect the liquid being stored from contamination by the substrate 3) To restore structural integrity to an old tank, while meeting the requirements for protection of the substrate from corro- sion and the liquid in storage from contam- ination All coatings are permeable to some degree. The choice of coatings as tank lin- ings requires a much greater knowledge of the properties of the liquid being stored and the ability of the coating to withstand permeation by that liquid than would typi- cally be required for any coating being applied in atmospheric service. Choosing a Tank or Containment Lining Few project managers have an in-depth knowledge of the suitability of various tank linin g s w h en pl a c ed in imm ersion of aggressive, penetrating liquids. It is possi- ble to review the product data sheets of sev- eral global scope and specialty scope man- ufacturers to get a general idea of which linings might work in a given situation. However, this approach is risky in that the product data sheets, of necessity, must be quite general in nature. There are three rec- ommended alternatives that will provide choices with better chances of success in a given application: 1) Comparative side-by-side testing of candidate systems in a laboratory program that simulates, to the best extent possible, the service conditions expected in that par- ticular tank. This takes time but can pro- vide very good indications of a lining's resis- tance to permeation by a particular liquid for a given period of time at a stated storage temperature. 2) If time does not allow for compara- tive laboratory testing, the candidate coat- ing manufacturers can be requested to pro- vide their chemical suitability tables for the products that are being considered for a particular tank. Although this normally is limited to specific testing for specific time frames such as 30 and 60 days, it often pro- vides reliable guidelines about the perfor- mance characteristics of each product. In addition, these suitability tables normally include some ver y valuable precautions regarding immersion based on the pH, tem- perature, etc., of the chemicals. Some very valuable information is normally available about cleaning chemicals, procedures, and recovery times between different cargoes. 3) Review selected case histories of tank linings used in similar services. This can be ver y valuable as it provides longer-term results. However, when doing so, the proj- ect tank and containment linings manager must be careful to confirm that the service conditions are truly similar to the expected service conditions. He or she must also be careful to confirm that the product shown in the case history is still formulated the same as it was when that case history was conducted . Volatile organic compound requirements have caused changes in prod- ucts to achieve higher volume solids that can, and have, drastically altered the chem- ical resistance of some products. This article is adapted from The Pro- tective Coating User's Handbook, Louis D. Vincent (Houston, TX: NACE International, 2010), pp. 147-148.

Articles in this issue

Links on this page

Archives of this issue

view archives of Materials Performance Supplements - TANK 2018