5.3 ERMUSR 09-11-2018 - Laserfiche WebLink

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SP0178-2007 Section 4: Fabrication Practices 4.1 All design practices in Section 3 shall apply to all (a) with the use of properly sized heaters; fabrication. (b) by placing the tank on a concrete pad topped with 4.2 All welding shall be continuous. Intermittent or spot a 100-mm(4-in.)layer of vermiculite concrete; welding shall not be allowed. (c) by insulating with a high-compressive-strength 4.3 Fillets and corners must be accessible for grinding. structural grade insulation between the tank bottom and foundation; 4.4 Field tanks fabricated for use with high-heat-cured linings(e.g., unmodified phenol formaldehyde thermosetting (d) by installing an internal temporary false bottom linings)should have bottoms suitably insulated and installed approximately 1.5 m (5.0 ft)above the floor of the tank on properly drained foundations to facilitate proper cure of prior to the final high-temperature bake;or the lining on the floor of the tank. Because the sand-filled earthen foundation, concrete pad, or other similar (e) by other suitable means that practically and foundation is a poor insulator, some means must be effectively ensure a properly cured lining on the tank considered prior to the application of the lining either to floor. override the heat sink or to distribute the heat uniformly. This may be accomplished in several ways: Section 5: Surface Finish Practices 5.1 Sharp edges shall be ground to a smooth radius of at prepare the weld surface and surrounding metal least 3.2 mm (0.13 in.) or as agreed between the tank or surfaces in accordance with the specification. Over- vessel fabricator, tank or vessel owner, and lining grinding, which would result in decreasing the wall applicator. thickness or the integrity of the weld beyond the limitations imposed by good welding practices, 5.2 Tank and vessel internal surfaces to be lined shall not applicable welding codes, or tank or vessel ratings, be marred by gouges, handling marks, deep scratches, shall be avoided. metal stamp marks, slivered steel, or other surface flaws. Flaws shall be repaired by welding or grinding, as 5.4 Automatic machine welds may be acceptable as appropriate. dictated by the specifications for film continuity. 5.2.1 Limits on surface flaw depth and geometry shall 5.5 All weld spatter and arc strikes must be removed. be set by agreement between the tank or vessel Chipping may be used if followed by grinding or the use of fabricator,tank or vessel owner,and lining applicator. an abrasive disc. 5.2.2 All restorative welding shall be performed 5.6 If an anti-spatter material is applied adjacent to the according to applicable tank or vessel design codes, weld area prior to welding, the anti-spatter material shall be approved job-specific procedures,or both, one that is readily removable. Anti-spatter materials shall be removed prior to abrasive blasting. 5.3 All rough welds shall be ground to remove sharp edges and other such irregularities (see Figure A2, Appendix A). 5.7 When checking weld continuity, the tank or vessel Chipping may be used to remove sharp edges if followed by fabricator shall avoid the use of oils, lubricants, or other grinding. See Appendix C for written and graphic foreign materials that would leave a contaminating residue descriptions of five degrees of surface finishing of welds not easily removed by abrasive blasting. that may be specified preparatory to the lining of tanks and vessels. 5.8 Surfaces shall be cleaned and decontaminated as required by the governing lining application specification(s). 5.3.1 The amount of grinding performed shall be judicious and performed only to the extent necessary to NACE International 3 186