Objectives of the Piping Punch Listing are mostly these 3 1. Acceptance of Piping Work by Quality Control Department of the Project 2. Highlighting of Balance work in Piping Construction to determine Time Frame for Completion 3. Giving the Go-Ahead for Hydrotesting of the Piping Segment or Test Pack Viewers you heard that one of the Objectives of the Punch Listing is to give the Go-Ahead for Hydrotesting so keep importance of Punch Listing in your mind that after Hydrotesting no one will allow to perform Hot Work or Welding Work on the Hydro Tested Piping once it is accepted. Try at most to capture all the Balance Hot Work through Punch List before the Hydro Test of the Piping. Viewers, for better understanding, we have divided this Topic into 6 Elements 1. Timing of the Punch List 2. Flow of the Punch List 3. Prerequisites for Punch List 4. Walk-Down for Punch List 5. Finalization of Punch List & 6. Verification of the Punch List Let’s come to the Number 1, Timing of the Punch List͟ Viewers when a Piping Segment is declared 100% Mechanically completed by the Execution or Construction Department, Quality Department is requested to highlight the deficiencies ( if any ) and to give the Go-Ahead to Execution Department for the Hydro Testing of that particular Piping Segment. Due to certain reasons some time Client or your own Execution Department requests you to prepare Punch List of a Line Segment before its 100% Mechanically Completion. In this situation the intention is to estimate & bring the Balance Work under control so that with a precise planning all the Line Segments could be completed 100%. Number 2, Flow of the Punch List͟ Viewers do not compromise over the agreed Flow of Test Pack. Test Pack is a set of Documents, related to a particular Line Segment, offered to you to prepare a Punch List. While receiving the Test Pack, Field Piping Inspectors or Engineers should ensure A, the signatures of Execution Department on declaration of 100% Mechanically Completion of a particular Test Pack & B, the Signatures of NDT Inspector on Weld Summary or Weld Map of the Line Segment or of the Test Pack. Number 3, Prerequisites for Punch List͟ Viewers take care of these points coming ahead. A. Test pack with the latest version of P&ID;, Isometric or Weld Map, Pipe Supports Drawings & NDT Summary already signed by the NDT Inspector. B. Contractor Quality Control Inspector. C. Contractor Piping Supervisor. D. Some Measuring Tools Like Meter Tape, Large Tri Square, Spirit Level. Number 4, Walk-Down for Punch List͟ Viewers take care of these points coming ahead. A. Preferably perform the Walk-Down jointly with Construction Contractor. B. Start the walk-Down with the peace of mind from the easiest end of the Line Segment. C. Start the verification of the completion of the Line Segment with the help of Isometric Drawings or Weld Maps, Pipe Supports Drawings but preferably with the help of P&ID.; D. Comprehensively note the Deficiencies with permanent pen, not with the Pencil, on Isometric or Weld Map & on P&ID.; E. While noting the Deficiencies, mention Exact Location of each Deficiency so that it could be Accessed & Rectified later without your guidance or Presence. Use Free Hand Circles or Arrows on the Drawings to mark Exact Location of the Deficiency or Punch Point. Also use these phrases to mark the Exact Location ͞Between Weld No. this & this͟ ͞Near the Weld no. this͟ or ͞Near the Column No. this͟ etc. etc. F. Do not compromise on Slope & Verticality of the Lines beyond the Acceptance Limit. To determine the Verticality or Slope on Line use Welding Electrodes of different Diameters by putting them under the one end of Spirit Level. Use the formula, Diameter of Electrode divided by the Length of Spirit Level & multiply by 100 to determine the slope or Verticality of Line Segment. If your Spirit Level is 300mm long & you are using Electrode having 2.4mm Diameter to level the Spirit Level then out of Verticality or out of Slope value is 0.8% or 8mm per Meter or 8 : 1000. G. Focus on Distorted Welded Joints. Mark these joints to Cut & Reweld. Never give the Go-Ahead for any Hydro Testing if a Distorted Joint exists in to the Piping System. H. Capture such Welded Joints that are not shown on the Weld Maps. I. Do not forget to capture Parallelism of Line Segments in Horizontal Plane with the help of Piping Plans or Piping General Arrangement Drawings. J. If Lines are not 100% completed & you are requested to prepare the Punch List then never forget to mention the Line condition on Punch list that the line is resting on Scaffolding or on resting on Woods or the Line is hanging with Ropes etc. etc. Number 5, Finalization of Punch List͟ Number 6, Verification of the Punch List͟

• published: 29 Apr 2018
• views: 12569