standard specification for fabrication and erection of piping

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5.2 By Hand The pipe may be lowered with the help of tripods and chain pulley blocks into the trench immediately after the coating and wrapping. However, if in the opinion of the Engineer in charge that the temperature conditions do not allow direct lowering, then the pipes shall be set down on clear square cut skids. The skids shall be so spaced as to keep the pipe away from touching the ground. Method & Time of Lowering Pipe Under favourable temperature, conditions and using methods which will not damage coating, the pipe may be lowered into the trench. Pipe previously set on skids, because of un-favourable temperature conditions shall be lowered into the trench normally in the cool of the morning and only when the temperature of the pipe is below the softening point of the coating materials. All skid marks and other places of damage shall be thoroughly examined to ensure proper patching where necessary, before the pipe is finally lowered into the trench. 6.0 Handling coated pipe Coated pipe shall not be placed in trench until cave in plugs, hard clods; stones, skids, welding rods etc. have been removed there from. Where the trench has a hard or jagged bottom, sufficient fine dirt or sand shall be placed therein, before the pipe is lowered. Coated pipe shall not be handled or moved by means of cable or chains or by praying with skids or bars, it shall be tightened and lowered by using lowering in belts of a standard width and design for the size of pipe being handled. Coated pipe shall not be dragged along the ground or otherwise handled in a manner that will be detrimental to the coating. Lining up and welding The ends of the pipe line shall be kept securely closed to prevent entry of any foreign material / moisture after lowering into the trench. Before making joint, the pipe shall be carefully laid so as to be perfectly aligned in both plan and profile, and the end closure provided shall be removed. Tie in shall be made in the coolness of the morning or when the ambient temperature is not exceeding 29 deg C or softening temperature of the coating material whichever is less. All beveling aligning and welding shall be in accordance with the welding specification given in the tender. Free access shall be provided for the welding of the circumferential joints by increasing the width and depth of the trench at these points. There should be no construction to the welder from any side so that good welded joint is obtained. Testing & coating wrapping
The completed system shall then be tested as per clause 6 and the field welded joints coated and wrapped as per specification. 7.0 Back Filling After testing and inspection of the pipeline to the entire satisfaction of the Engineer in charge, the trench shall be back filled with the excavated material. No trench shall be back filled without the approval of the Engineer in charge. Backfilling with the excavated material shall be done in layers of 200 mm well watered and rammed to avoid any settling afterwards. The contractor shall place soil over the trench to such a height as well as in opinion of the Engineer in charge, to provide adequately for future settlement of the trench backfill. If due to exigencies of the work, some portion of the pipeline is backfilled without approval of the Engineer in charge, the engineer in charge shall have the right to order uncovering of the pipe for examination and the cost of such uncovering shall be borne by the Contractor. The backfill material shall free from stone pieces. Surplus excavated soil or rubbish material shall be removed by the Contractor at his own cost to a place designated by the Engineer in charge. When the trench has been dug through roads, all backfill shall be thoroughly compacted. In certain cases, special compaction methods may be required by the Engineer I charge. This shall be done by the contractor at no extra cost to the owner. When the trench has been dug through unlined ditches the backfill shall be thoroughly compacted in 150 mm layers for a distance of 1.50 m beyond the outside banks of the ditch on either side. The banks of the ditch shall also be compacted in 150 mm layers at no extra cost to the owner. After the roads have been already graded and if they are trenched or otherwise disturbed by the Contractor during laying of the pipe lines, the contractor shall restore the road to its original level and condition. In the event, the contractor is required to place extra fill, gravel, or other special materials it shall be done by him without any extra cost to the owner. Clean up of surroundings As soon as the backfill is completed, the contractor shall immediately clean up the adjoining area by removing all surplus and defective material and dispose of all refuse such as spurs, sheet-iron, broken skids, etc. to the complete satisfaction of the Engineer in charge. The earth on both sides of the pipeline trench which has been disturbed during the construction of the pipe line shall be smoothened and left in a condition satisfactory to the Engineer in charge. 8.0 INSPECTION General Owner’s inspector shall have free access to all places where the work is being done or any other thing and place concerned with the work.
Page 1 and 2: STANDARD SPECIFICATION FOR FABRICAT
Page 3 and 4: Std. spec for earth work for U/G pi
Page 5 and 6: All field fabricated piping shall a
Page 7: space on each side of the pipe. The
Page 11 and 12: The field test pressure shall where
Page 13 and 14: All piping attachments, such as cou
Page 15 and 16: 5. SHIELDING & PURGING GAS : 5.1 Ar
Page 17 and 18: 9.6 Engineer-in-charge shall check
Page 19 and 20: g) Automatic temperature recorders
Page 21 and 22: ) The extent of Radiography shall b

standard specification for fabrication and erection of piping

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