The purpose of this piping fabrication procedure is to provide guidelines to carry out all the activities in a systematic way for fabrication and erection of stainless steel piping and to ensure that all concerned personnel have the common understanding to achieve the highest quality of workmanship and the safe execution of the ss piping works.
SS piping work shall be done s per Applicable Codes, Standards, Procedures, approved drawings and welding details as per approved WPS & PQR.
All materials will be identified for particular job. Piping, Valves & specialties will be as per approved technical data sheets. All material will be identified by using size, Dia, length & color codes and stored item wise separately. Schedule of material to be provided for procuring the materials i.e. (Item description, standard-ASTM A312/A312-13, grades and identification)
Abbreviations & Definitions:
ASME: American Society of Mechanical Engineers
ASTM: American Society for Testing and Materials
ANSI : American National Standard Institute
ITP: Inspection & Testing Plan
WPS: Welding Procedure Specification
PQR: Procedure Qualification Record
Tools & Equipment’s
All major lifting equipment’s tools and accessories listed below for the fabrication/erection will be arranged by site Engineers. Engineer will reserve its right to select and use the appropriate tools, equipment and accessories based on actual site condition and as per requirement.
- Hydraulic Crane
- Welding machine
- Welding torch
- Chain Blocks
- Grinding machine
- Spirit lens
- Wire ropes / Nylon ropes
- Argon Gas cylinder
- Wire brush
- Shackles
- Hand tools
- Pulley
- Hydro Testing Pump
- Safety belt
- Slings
- Hammer
- Measuring tape
General Requirements for SS Piping Fabrication
Welding: All welding procedures, welders and welding operators shall be qualified by in accordance with ASME requirements and job specifications. Fit up shall be performed by tack weld with Argon gas shall be performed by approved welder.
Cleaning of Piping: All pipes shall be cleaned prior to fabrication/erection wire brushed to remove all rust and mill scale from inner surface. The method of cleaning shall be such that no material is left on the inner or outer surfaces of pipe.
Fabrication: Pipe welding ends for GTAW (Gas tungsten arc welding) as per relevant standards. To weld the fit-up joints the welder shall clear the test before employed for welding.
Pipe Supports: Prior to installation of pipes, temporary pipe supports shall be installed (If required) or the permanent supports will be installed as specified in the drawings & technical specification. Supports permitting pipe movement shall be assembled as specified. Pipe support distance shall be as per technical specification.
Expansion Joints: Installation of expansion joints shall be accordance with the manufacture’s requirements and recommendations unless otherwise specified. Expansion joint bellow should be incorporated in the shop drawing.
Valves: Valves may be either with flanged ends or threaded ends & should be installed as per approved drawings and technical specifications.
End Caps: All screwed or welded end caps are to be installed as specified in the drawings or as per consultant requirements.
Testing: Hydro pressure test shall be performed after completion of pipeline in all respects. The test pressure will be as per technical specification. The hydrostatic test shall be taken in confidence of client.
Resource Requirements
The Staffs & Manpower (PM, ENGR, QA/QC etc.) will be identified for to complete the particular job and each staffs & manpower job responsibility will be identified and defined. Only trained and certified personnel will be allowed for to complete the target.
Sufficient Material, manpower with necessary tools and equipment’s, as required, for safe and timely completion of the work shall be deployed and these will consist of but not limited to the following.
Engineers
Safety
Rigging Skilled workers
Fitter welder
Unskilled workers
Foremen
helper
Stainless Steel Pipe Fabrication Procedure
Pipe will be identified by dia & grade and before starting the fabrication, pipe will be cleaned from inside. SS pipe will be either 304 or 316 L grade.
The length of pipe will be marked as per approved drawings/Isometric drawings and cut by using hack saw cutter & grinder.
Pipe level will be checked before welding and will be done as per approved groove angle.
Joint fit-up will be done as per approved WPS/Specifications (GTAW).
Depending on site conditions, assemble the piping into manageable lengths on the floor, using welded jointing as applicable.
Joint welding to be done by qualified welders as per approved WPS.
After completion of welding, joint to be cleaned by wire brush.
Joint inspection will be done as per approved ITP and reports shall be maintained.
Piping Erection Method
Pipe Spools will be identified before installation of pipe.
As per approved drawing temporary or permanent support will be installed before erection of Pipe Spools. Supports distance will be maintained as per specifications.
Before installation of pipe spools support painting to be done as per specification/ approved data sheet.
After support installation pipe spools inside will be checked and again it has to be cleaned by compressed air/wire brush.
Pipe spools to be erected as per approved drawing using proper handling equipment.
Align and level the piping as per approved drawings.
Joint fit-up will be done as per approved WPS/Specifications.
Joint welding to be done with GTAW (Gas tungsten arc welding) by qualified welder as per approved WPS.
After completion of welding, joint to be cleaned by wire brush.
On surface of all welding joints either K2 paste solution or Buffing wheel to be used to avoid joint blackness.
Valves, flexible joints & Specialties shall be installed as per approved drawing.
Permanent supports will be fixed as per approved drawing.
Install drain points at lowest level and install vent point at highest level in main line.
Joint inspection will be visual with 5% Radiography.
Line inspection will be done before giving the clearance for pressure test and test reports to be maintained.
Quality Inspection & Testing Procedure
After installation of ss piping as per approved drawing final line inspection will be done before pressure test of complete steel piping system.
Weld inspection report and erection checklist to be completed before Hydro test pipe as per approved ITP.
Following to be inspected:
All debris shall be removed from the pipes.
Necessary welds shall be completed & randomly tested by 5% radiography.
Make sure flange joints are all tightened.
All necessary valves shall be installed and opened.
Make sure that sufficient drain points & vent points provided.
Calibrated pressure gauges shall be used for pressure test.
All instrumentation shall be isolated.
Vents points necessary to prevent air entrapment during filling shall be opened if required.
Make temporary tapping provisions for filling and draining of pressure testing water.
Test Water will be filled using temporary provisions.
Using pressure pump, required pressure as per specification or 1.5 times of design pressure to be raised for retaining time of 180 minute.
All welding joints & flange joints shall be checked for any leakages.
If any leakages are found, water shall be drained and leakage will be rectified. Again pressurize the system using pressure pump. All safety precaution to be taken during hydro testing.
During pressurization observe the joints and entire piping system for leakages and raise the pressure up to required testing pressure.
If no leakages are found hold the pressure up to specified/approved time.
Inspection report to be maintained.
Environmental Protection Guidelines
- The generation of waste should be avoided or minimizes wherever possible.
- Worksite and premises shall be maintained in a healthy, clean and sanitary condition.
- The walkways and roadways shall be maintained clean.
- Special attention shall be given to remove the slipping and tripping hazards.
- Stack or place material, tool and other equipment in such way that no hindrances to occur in actual work area.
- Remove trash and debris daily from the worksite and premises including nails & welding stubs.
- Remove combustible scrap at regular intervals.
- Separate housekeeping person to be engaged depending the site requirements and environment will be checked on daily basis by safety persons.
Health and Safety Requirements
| Sr. No | ACTIVITY | PERFORMER | FREQUENCY | REMARKS |
| 1 | Safety committee meeting | PMC | As per approved manual | To be attended by the Site safety In charge and as required. |
| 2 | Safety induction for workers and for the Staff members | Site Safety In charge | Prior to engaging the workers / staff for site activity | All personnel to be engaged for
site activity should undergo safety induction compulsorily. |
| 3 | Conducting tool box talk on daily basis at Site. | Site Safety In charge | Daily morning /prior to new activity. | |
| 4 | Tools and equipment inspection | Site Safety In Charge | As required
frequency |
Project engineer in coordination with the safety in-charge shall carry out Inspection activity. |
| 5 | Inspection of the Scaffolding and temporary structure for working At height. | Site Safety In charge | Completion of erection and prior to use and after any change in the work conditions. | Site in charge shall identify the competent person |
| 6 | Electrical safety inspection | Site Safety In charge | Once in every 15 Days checked & tagged by client every 3 months | Electrical Engineer in coordination
with the Safety in charge shall carry out inspection activity & tags to be attached. |
| 7 | Inspection of fire Extinguisher. | Site Safety In charge | Every three month | |
| 8 | Inspection of First aid facility | Safety In charge | During site audit | |
| 9 | Safety Inspection | Safety In charge | During site audit | Concerned person should accompany the project engineer. |
| 10 | Certification of all equipment | Project Engineer | When the equipment first enter the site and before starting the use of equipment | Project engineer in coordination with the site safety in charge shall carry out inspection activity. |
| 11 | Safety statistical report | Site Safety In charge | Every month | Man Hours worked can be calculated at actual basis. |
| 12 | Third party inspection of the lifting tools and tackles | Competent person as per the factories act, Safety in charge, QA/QC | Once in a year | Project engineer in coordination with the safety in-charge shall verify the certificate prior to hire the cranes etc. |
| 13 | House keeping | Site engineer | As required | Separate gang & timings |
Risk Assessment& Hazard Analysis
| Sr. No | Sequence of job steps | Risks Identified | Precautions advised |
| 1 | Unloading of SS pipes | Fatigue/fall of pipes | Unloading work with trained people. Use trained rigger & pre inspected/tested slings, use of PPE’s like hand gloves, helmet & Shoes. |
| 2 | Use of cutter & grinder for pipe cutting | Electric shock | Inspect connection cable before use. Use pin Top. Employ trained persons. |
| Breaking of wheel | Inspect the wheel before mounting. Ensure the RPM of the M/Cs suit to the wheel Grade.
Tighten the flange nut properly. Employ trained persons. |
||
| Eye injury/ Injury due to Flying sparks/particles. | Ensure the wheel guard. Employed trained Persons. Use Proper PPE. | ||
| 3 | Use of gas cutter for pipe cutting. | Fire/Explosion | Hot work permits system. Ensure fire extinguisher, flammable material should be removed or covered with fire blankets. Housekeeping standards to be followed. Checked for leakage and ensure flash back arrester is in working condition. Employ trained persons. Use proper PPE. |
| 4 | Welding | Electric shock | Follow work permit system. Cable joints to be checked. Use ELCB & proper lugs connections. Use pin top. Employ trained persons. Use proper PPE. |
| Fire due to welding work | Hot work permits system. Ensure fire extinguisher, flammable material should be removed or covered with fire blankets. Housekeeping standards to be followed. Checked for leakage and ensure flash back arrester is in working condition. Employ trained persons. Use proper PPE. | ||
| Burns injury | Employ trained persons. Use proper PPE. | ||
| 5 | Fixing fasteners concrete ceiling | Fall from height. (Use of ladder, & scaffold fall of person/tools/pipes) Eye injury | Height work permit. Use proper access. Use Proper safety belt with proper anchorage.
Inspection of ladder, Scaffold before use. Employ trained persons and use proper PPE. Use safety goggle & proper PPE. |
| 6 | Fixing of pipes. | Fall on the passer/working nearby fall of person/tools. | Barricade area. Use trained rigger. Height work permit. Use proper access. Use Proper safety belt with proper anchorage. Inspection of ladder, Scaffold before use.
Employ trained persons and use proper PPE. After completion of work unwanted materials to be removed from scaffold. Employ trained persons and use proper PPE. |
| 7 | Working at height | Fall from height. (Use of ladder, scaffold, fall of person/tools/pipes.) | Height work permit. Use proper access. Use Proper safety belt with proper anchorage.
Inspection of ladder, Scaffold before use. Employ trained persons and use proper PPE. |