1 page 1 of 183 . Page 2 of 183. Page 3 of 183. PIPING manual . INDEX. Sl. No. Topics Page No. Scope 6. Definition 7. Pipe 7. Tubing 7. Type of Pipes According to the Method of 8. Manufacture Electric Resistance Welded Pipe (ERW) 8. Furnace Butt Welded Pipe 8. Electric Fusion Welded Pipe (EFSW) 8. Submerged Arc Welded Pipe (SAW) 8. Double Submerged Arc Welded Pipe 9. Spiral Welded Pipe 9. Seamless Pipes 9. Centrifugally Cast Pipes 9. Statically Cast Pipe 9. Cement Lined Pipe 9. Concrete Embedded Pipe 10. Selection of Material 12. Scope 12. General 12. Guidelines for Material Selection 13. Specific Requirement for Special Services Sour 17. Gas, Hydrogen, Sulphur, Ammonia, Amines, Caustic Services etc. Guideline for Pipe Specifications for Cooling 19. Water & Fire Water Piping Systems Common Materials used in Refinery 19.
2 Significance of Piping Class Nomenclature 46. used by Designers and PMCs Significance for First Alphabet of Piping Class 46. Significance of Second Letter of Piping Class 46. Significance of Third Alphabet of Piping Class 48. Significance for Last Alphabet of Piping Class 48. Necessity of inspection 50. inspection Tools 51. Frequency of inspection 53. Plant Piping 53. Offsite Piping 53. Likely Areas of Metal Loss and Causes of 55. Deterioration External Corrosion 55. Internal Corrosion 55. inspection Stages & Procedures 59. Page 4 of 183. Sl. No. Topics Page No. Onstream inspection (Pipelines under 59. Operation). inspection During Shutdown 66. Statutory inspection 68. Quality Assurance Plan for New 71. Constructions Quality Assurance during Design Stage 71. Quality Assurance during Construction Stage 74.
3 inspection of Piping during Fabrication 78. inspection of Pipes before use 78. Injurious Defects 78. Forming of Pipes 79. Welding 80. inspection after Welding 80. Supports 81. Pressure Tests 81. Painting 86. External Corrosion Control for Buried or 87. Submerged Pipelines Insulation 88. Retiring Limits 90. Pipeline Repairs and inspection 91. inspection of Valves in Service 91. Documentation 93. Annexures 95. Annexure I Extracts from ANSI/ ASME B On 95. Liquid Petroleum Transportation Piping Systems Annexure II Preservation of New Pipes in Ware House 99. Annexure-II(a) Sample Preservation Scheme for Sulfur 100. Recovery Unit Annexure-II(b) Idle Time Preservation Scheme for Amine 106. Treating Unit Annexure-II(c) Procedure for Passivation of Austenitic Stainless 110. Steel Equipment Annexure-II(d) NACE RP-0170 - On Protection of Austenitic 114.
4 Stainless Steel Equipment Annexure-II(e) Idle Time Preservation of Static & Rotary 120. Equipment OISD-171. Annexure III Dimensions of Seamless and Welded Steel Pipe 150. Annexure IV Equivalents Specifications of ASTM to British, 153. French, German, Italian and Swedish Standards Annexure-V Common Paint Colour Code for Refineries 156. Annexure-VI Standard Specification for Corrosion Protection 170. of Wrapping Coating & Tape Coating of Under Ground Steel Pipelines Annexure-VII A Sample of Isometric of Pipeline Circuit & Data 181. Record Cards References 183. Page 5 of 183. SCOPE. This manual covers the minimum requirements for inspection on pipes and pipefitting used in petroleum refinery. Locations to be inspected, inspection tools, inspection frequency, likely location of deterioration and causes, inspection and testing procedures have been specified in the manual .
5 Special emphasis was given on the quality assurance requirements in new projects and Additional Facilities (AF) jobs in view of the recent failures encountered in new projects. Critical issues of material selection and Common Paint Colour Code System have also been covered. Experience of newly completed projects is also incorporated to avoid repetitive failures on these accounts. inspection and testing requirements of new pipeline during fabrication have also been included. Page 6 of 183. DEFINITION. PIPE. A pressure tight cylinder used to carry a fluid or to transmit a fluid pressure is designated Pipe in applicable material specifications. Pipe manufactured in different sizes & thicknesses are commonly expressed in nominal diameter. Nominal diameter is normally the approximate internal diameter of the pipe with standard schedule thickness.
6 TUBING. Tubing is similar to pipe but it is manufactured in different sizes of outside diameter and wall thickness. Tubing is generally seamless drawn and the stated size is the actual outside diameter. Tubes are basically meant for heat transfer and mostly fit into tube grooves, hence tubes are specified by outside diameter and wall thickness with negative tolerance on outside diameter. Page 7 of 183. TYPE OF PIPES ACCORDING TO THE METHOD OF. MANUFACTURE. ELECTRIC RESISTANCE WELDED PIPE (ERW). Pipe produced in individual lengths or in continuous lengths from coiled skelp, having a longitudinal or spiral butt joint where in coalescence is produced by the heat obtained from resistance of the pipe to the flow of electric current in a circuit of which the pipe is a part, and by the application of pressure.
7 Care must be taken during procurement of ERW pipes as regards the code requirement. The IS-1239 and IS-3589 does not call for any mandatory requirements of NDT to ensure the quality of welding. Moreover, the hydrotest requirement can be substituted by NDT by manufacturer without informing the customer. As per API 5L the NDT. requirement for quality assurance of weld is mandatory and the manufacturer have to keep 100% record of hydrotest for witness by the TPI agency. Any additional requirement should be specifically indicated in the purchase order. FURNACE BUTT WELDED PIPE. i Furnace Butt-Welded Pipe (Bell Welded). Pipe produced in individual lengths from cut-length skelp having its longitudinal butt joint forge welded by the mechanical pressure developed in drawing the furnace heated skelp through a cone- shaped die (commonly known as the Welding bell ) which service as a combined forming and welding die.
8 Ii Furnace Butt-Welded Pipe (Continuous Welded). Pipe produced in continuous lengths from coiled skelp and joint forge welded by the mechanical pressure developed in rolling the hot-formed skelp through a set of round pass welding rolls. ELECTRIC FUSION WELDED PIPE (EFSW). Pipe having a longitudinal or spiral butt joint wherein coalescence is produced in the preformed tube by manual or automatic electric-are welding. The weld may be single or double and may be made with or without the use of filler metal. SUBMERGED ARC WELDED PIPE (SAW). The submerged arc welded pipes are made from hot rolled coils or sheets. The welding can be longitudinal or spiral. The pipe is welded internally and externally using submerged arc-welding process. Page 8 of 183. DOUBLE SUBMERGED ARC WELDED PIPE. Pipe having a longitudinal or spiral butt joint produced by at least two passes, one of which is on the inside of the pipe, coalescence is produced by heating with an electric arc between the bare metal electrode or electrodes and the work.
9 The welding is shielded by a blanket of granular, fusible material on the work. Pressure is not used and filler metal for the inside and outside welds is obtained from the electrode or electrodes or fusible material. SPIRAL WELDED PIPE. Pipe having a helical seam with either a butt, lap or lock seam-joint which is welded using either a electrical resistance, electric fusion or double submerged arc weld. SEAMLESS PIPES. Pipe produced by piercing a billet followed by rolling or drawing or both. CENTRIFUGALLY CAST PIPES. Pipe formed from the solidification of molten metal in a rotating mold. Both metal and sand moulds are used. The inherent parabolic internal pipe contour formed by the centrifugal force during solidification, is subsequently removed by boring to sound metal. STATICALLY CAST PIPE.
10 Pipe formed by the solidification of molten metal in a sand mould. CEMENT LINED PIPE. Internal and external cement lined pipes are used in cooling water and fresh water lines to combat microbial induced corrosion in the internal surface and soil corrosion in the external surface. The cement lining is normally 25mm thick on inside and outside with wire mesh as reinforcement. Cement lined pipes are fabricated at shop on need base and can be manufactured for higher diameter pipes only. However, precautions should be taken for handling/ fabrication of these pipes to avoid local damage or cracks on the cement lining and the lining provided at the insitu joints. While doing the welding for field joints asbestos-backing ring should be suitably provided at the internal face to avoid direct contact of water to the metal surface.