*Corresponding author: Hafiz Abdul Ahad Qazi, Department of Quality Control Health and Safety Environment, Pakistan, Tel: +923448344723, Email: ahadqa- zi10@yahoo.com Citation: Qazi HAA (2019) Study of Qualification of Coating Procedure Spec- ifications as Per Din 30670 for 3lpe Coating of 8 Inch Diameter Erw Pipe, Pakistan. J Environ Sci Curr Res 2: 008. Received: March 15, 2019; Accepted: April 17, 2019; Published: April 25, 2019 Copyright: © 2019 Qazi HAA. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction Since the advancements in piping technology for oil and gas trans- portation, three layer polyethylene coating have been in use for not only giving corrosion protection to the pipelines but also enhancing the service life of it. 3LPE (Three Layer Polyethylene) systems con- sists of frst functional layer: a high performance Fusion Bonded Ep- oxy (FBE) an anticorrosion layer, followed by second functional layer a copolymer adhesive which makes bond between epoxy and polyeth- ylene and third functional layer an outer layer of high density poly- ethylene which provides tough and durable protection. 3LPE coating systems provide the most effcient pipeline protection for small and large diameter pipelines with moderately operating temperatures from -40ºC up to 80ºC which is comparatively higher range. Prior to start of regular coating production of each order, a proce- dure qualifcation trial is adopted for each pipe diameter range, Inch, for each combination of coating material, and for each plant, to set up that plant, materials and coating procedures resulting quality of fnish product confrming to the properties of the material, relevant stan- dards, specifcations and material manufacturer’s recommendations. In current study, coating procedure qualifcation is performed for 8 inch diameter ERW pipe, four test pipes are selected for coating pro- cedure qualifcation. Out of four test pipes, one pipe coated with adhe- sive, one pipe coated with epoxy, one pipe coated with polyethylene and one pipe coated with all three layers. Properties of the starting raw materials as mentioned in test certifcates supplied by the respective manufacturers is compared with the standard specifcations raw mate- rials include client supplied bare pipes which are manufactured as per API 5L 45th edition. Surface preparation raw materials which include steel grit, phosphoric acid and chromate. Coating raw materials which include epoxy powder, copolymer adhesive and high density polyeth- ylene. Surface Preparation Materials Properties Seen from tables 1-3. Methodology Client supplied bare pipes were visually inspected for surface de- fects dents, pits, bevel and root damage, straightness, surface contam- ination etc., QC cleared pipes sent for surface cleaning process while rejected pipes sent for re-working or replacement. Detailed coating process steps are presented in fow diagram below (Figure 1). Qazi HAA, J Environ Sci Curr Res 2019, 2: 008 HSOA Journal of Environmental Science: Current Research Research Article Hafz Abdul Ahad Qazi* Department of Quality Control Health and Safety Environment Engineer, Kotri, Pakistan Study of Qualification of Coating Procedure Specifications as Per Din 30670 for 3lpe Coating of 8 Inch Diameter Erw Pipe Abstract In present study qualifcation of 3 layer polyethylene coating pro- cedure is discussed which is adopted for the corrosion protection of API 8 Inch ERW line pipes. API monogrammed bare pipes were supplied by the local manufacturer while coating was performed as per DIN 30670 standard. Raw materials including surface prepara- tion and coating raw materials steel grit, acid and chromate, epoxy, adhesive, HDPE and bare pipes were tested and compared with the manufacturer testing certifcate for specifcation compliance check, results are presented in tables 1-4. Physical inspections of bare pipes were carried out before assigning unique identifcation number to each pipe. Surface preparation including pre-heating of pipes at least 3ºC above dew point temperature, steel grit blasting of pipes to get the desired Sa 2.5 surface with 50 to 80 microns profle, acid washing of pipes to remove excess chloride ions, Rinsing of pipes after acid washing with RO water, drying of pipes through blowers, induction heating of pipes up to the epoxy manufacturer recom- mended temperature which is 200 to 220 degree celsius, frst layer epoxy powder application through electrostatic spray gun technique, second layer of adhesive and third layer of Polyethylene flm appli- cation through side extrusion process, quenching of coated pipes, full length coating holiday inspection and in the end Final inspection of coated pipes. Four test pipes were selected for coating procedure qualifcation. Out of these 4 test pipes, First pipe coated with adhe- sive layer for adhesive layer thickness measurement, Second pipe coated with epoxy layer for epoxy layer thickness measurement, third pipe coated with Polyethylene layer for polyethylene layer thick- ness measurement along with sampling for indentation hardness test, fourth pipe coated with all three layers and tested for thickness measurement of combined three layers, holiday detection, peel ad- hesion strength test, impact test and cathodic disbondment test. All testing were evaluated to check compliance against the standard DIN 30670 requirements and coating procedure specifcations. Keywords: Cathodic disbondment test; Chloride content test; Coat- ing procedure qualifcation; Coating procedure specifcations; Corro- sion protection; Dew point; DIN german institute for standardization; Elongation test; Holiday test; Impact test; Indentation Test; Peel Ad- hesion; Surface preparation; Thickness measurement; Three layer polyethylene coating (3LPE).