Work Methodology for Fire Protection Tapping Point Installation
1. All documents relevant to this particular section of work shall be check prior to installation.
2. Check the areas if ready for the installation and free from debris and unsafe condition.
3. Ensure that the pipe, fittings and anti-corrosion tape to be installed are clean and free of debris and foreign materials and suitable for installations.
1. Ensure that all shop drawings, plans are stamped / approved prior to the commencement of all fire protection works.
2. Secure necessary permits prior to installation.
3. Provide necessary measuring tools like meter tape, nylon string, L-bar and level bars to ensure the level of installation.
Tapping Point Installation (Line Stopping)
1. Shift the pipes/fittings/anti-corrosion tape to the required location. Underground pipes will be fabricated on site in accordance with the approved drawings.
2. Provide stand by fire water truck at the tapping point installation. Coordinate and inform the fire station for the installation at the tapping point near coal yard.
3. Check and closed the isolation valve (existing) based on the as-built drawing for fire water line near coal yard (tapping point). Coordinate through AES representative for the temporary shutdown of pipe line as per required schedule.
4. Drain the existing pipe (ductile iron). Cut, clean and provide protection to the edge of the pipe.
5. Measure length of pipe required with allowance for any pipe fittings to be used, cut the pipe required length (to be fabricate) ensuring that the ends are cut square and foreign materials are removed from pipe.
6. Prior to laying of the fabricated pipes/fittings, provide sand bag to the pipe for support and to attain the invert elevation as per approved plan.
7. Mount the D.I. universal adaptor (connection of D.I. pipe and B.I. pipe). Pipe joint shall have the proper bevel angle and root distance before welding of joints and free from rust, or other foreign materials.
8. Fit-up the entire pipe using mechanical level bar to ensure the level of pipes. Tack only joints fittings.
9. If the entire pipes conform the approved coordinates and inverts levels, proceed to full welding (See section 2.5.4).
10. Bedding shall be plane to enable correct and uniform supporting for the pipes. Ensure that the pipe will rest on firm undisturbed soil.
11. Thrust blocks shall be installed at locations where pipeline changes directions (bends tees), stops (at dead ends) or changes in size (at reducers). Additional thrust block shall be installed at locations as required based on hydraulic analysis and stress analysis report.
12. Provide isolation valve (OS&Y GV) after the road crossing. (See section 2.5.3)
13. Provide anti-corrosion resistant tape for underground piping. End laps between adjoining rolls of the wrap or between pipes sections shall conform to the manufacturing standard. (See section 2.5.6)
14. If pipes already passed the testing requirement, proceed with the application of anti-corrosion resistant tape for underground piping. End laps between adjoining rolls of the wrap or between pipes sections shall be conform to the manufacturing standard. (See section 2.5.4)
15. Pipes, wrapping and fittings shall be visually examined. Any defective or damaged coating/wrapping shall be repaired or replaced.
16. Prior to backfilling, additional bedding shall be placed and compacted around and above the top of the pipe for the entire width of the trench.
17. Provide warning tape directly above the concrete encasement/pipe prior to backfilling and compaction.
18. Coordinate to AES representative after the installation.
Valve and Valve Box Installation
22.214.171.124 Valve Box Installation
1. Transfer valve box into the place it will be mount.
2. Check the valve box against the depth of trench and pipe.
3. Excavate the material under the box location and backfill with suitable backfill material and compact.
4. Provide sufficient lifting points for a safe installation.
5. Prior to lowering, secure all inserts/sleeves at the place of installation. Arrange the surface level of the box to be fitted and set the box bearing firmly and fully on bedding.
6. When lowering valve boxes into excavation and joining pipe into units, take protections to ensure interior of pipeline remains clean.
7. Clean and prepare mating surfaces before assembly of pipes with structure. Lower, set level, and firmly position inserts/sleeves section.
8. Remove foreign materials from surfaces and maintain alignment between sections.
9. Provide non-shrink grout to seal the pipe connection.
10. Verify the valve box installed satisfies required alignment and grade.
1. Transfer valve into the place it will be base. Valves shall be installed in the right direction and right position.
2. Make sure that the pipeline and flange faces are clean. Valve must be closed position for installation.
3. The distance between pipe flanges should be checked to assure sufficient clearance for valve installation.
4. Ensure proper gaskets are used between the valve flange and pipe flange. (Flange connection shall conform to PMDL16-1861, section 2.5.4)
5. Align the pipe work and spread the flanges enough to allow the valve body to be easily inserted between the flanges without contacting the pipe flanges.
6. Place the valve into position. Lower the valve and set the level of the valve according to the flow arrow assembly.
7. Ensure that each valve is centered inside the bolt circle.
8. Check flange alignment. Lubricate on the washer, bolt threads and inside nut threads if necessary.
9. Tighten bolts and nuts in alternating sides until completely tightened.
10. Provide valve tags if needed.
1. Clean flanges and check for scars on the flange area. Remove burrs from all threads of stud and nuts
2. Check flange where nut makes contact. Area must be clean and smooth.
3. Flanges must be parallel and gasketed, and centered between the flanges.
4. The flanges will be mated and nuts shall be tightened to hold the gasket in place.
5. Care shall be taken to ensure proper centering, seating and sealing of the gasket.
6. Check flange alignment. Lubricate on the washer, bolt threads and inside nut threads if required.
Welding of Joints
No welding shall be done if the area is wet or exposed to high wind or at metal temperature below 32˚ F.
Selection of Filler Metals
Select the filler material best suited for the pipe material to be used. For the black iron and mild steel pipes 65mmø to 150mmø welding rod, 6011 for the first root passes and 6013/7018 for capping.
1. Hot work permits will be submitted at site prior to welding execution. Prior to work execution; check that the work area is free from debris or foreign materials that could obstruct the work to be carried out.
2. Ensure a copy of approved piping layout and detailed drawings showing elevations and details.
3. Welder certificate will be provided prior to execution of works.
1. Surfaces of pipes, fitting, flanges shall be clean and free from rust, or other materials which is detrimental to welding.
2. Pipe fittings, flanges to be joined must be perfectly aligned and perpendicular. Misalignment of the inside surfaces for piping components to be joined by welding may result in out of roundness.
3. The inside surfaces of the pipes to be joined by butt-welding shall be aligned so that the misalignment at any point on the inside circumference does not exceed 1/16”. Where it is impossible to adhere to this limit by moving one component extending internally by building up by welding, by expanding or by swaging.
It is preferred that these methods be applied to such an extent that the adjoining internal surface are approximately flush, however, internal trimming shall not be done to such an extent that it will result in the piping component wall thickness than the minimum design thickness plus allowances for the corrosion and erosion.
1. Butt joints are with single Vee, or other suitable type of groove.
2. Qualified welder shall make tack weld. Tack weld that are not removed shall be made with a filer material, which is the same or equivalent to the electrode to be used for the root pass.
3. Tack welds that have crack shall be removed. Before assemblies are transferred from location of fit up to location of welding, all joints shall have been adequately tacks welded, partially welded or fully welded so as to prevent cracking of the welds or distortion of the assembly during transfer.
4. Piping which is to be placed shall be properly aligned and adequately supported during tack welding and subsequent full welding in order to avoid cracking of welds.
5. If the internal surfaces are not aligned, the weld shall be tampered between the surfaces.
6. The welding shall be such that the following requirements are met;
a. The external surfaces of the butt welds shall be free from undercuts greater than 1/32” deep or half the weld reinforcement whichever is smaller.
b. The thickness of weld reinforcement shall not exceed the following, considering the thinner component being joined:
PIPE WALL THICKNESS
( inches ) REINFORCEMENT THICKNESS
( inches )
¼” and below 1/16”
Over ¼” through ½” 1/12”
Over ½” through 1” 1/8”
Over 1” 3/16”
c. Cracks not permitted.
d. Incomplete penetration.
The total joint penetration shall not be less than the thinner of the two components being joined, except to the extent that incomplete root penetration at weld root of girth welds shall not exceed 1/32” or half the thickness of the weld reinforcement, whichever is smaller.
e. Lack of fusion not permitted.
Welds must be steel brushes cleaned or grind before additional pass is done.
For protection of piping against corrosion, it must be painted with (2) two coat of Primer Oxide.
1. Make sure to remove all dirt and debris on the pipes before applying coatings on it.
2. Exposed B.I. piping, pipe recovering, equipment and support piping and enclosures shall have (2) two coats of Primer Oxide paint after installation, then (1) one coat of approved Enamel Paint for final coating after testing of pipes.
3. All pipe hangers, anchors and support shall be coated with Primer Oxide before installation.
Note: Must conform to the General Provision Section 15010 Part 3.8.1, 1 – 6.
1. For brush application, apply a wet coat in even parallel passes. Overlap each pass 50% to avoid base areas and pin holes.
2. Always stir during application to maintain materials uniformity.
3. At the end of each workday, remove empty cans, rags, and other discarded paint materials from the project site.
4. Provide “Wet Paint” signs to protect newly painted finishes.
Wrapping of Pipes
1. Surface shall be completely free from rust, grease, weld slag, dirt, oil and other foreign matter and to be dry at time of application.
2. Cleaning shall be carried out immediately before application of the primer coat.
1. The pipe surface must be thoroughly scrapped and wire-brushed and must be free from loose rust, dirt and dust, water, oil and grease.
2. Undercoat or prime the entire surface uniformly with Denso Paste at a covering capacity of 5 m2/kg.
3. Spirally apply Densyl Tape maintaining a 50% overlap (as per manufacturer’s recommendation). The tape must have sufficient tension to conform without stretching. The laps and entire tape surface must be pressed and smoothened with the hands in order to bind it firmly to the substrate and to ensure complete seal.
NOTE: The end lap of each roll shall overlap the end of the preceding roll by a minimum length of 200mm.
4. Spirally apply PVC Outerwrap Adhesive Tape with sufficient tension to conform without stretching maintaining a 50% overlap (as per manufacturer’s recommendation) to increase mechanical and dielectric strength.
NOTE: For steps 3 & 4, care shall be taken to ensure that no wrinkles, puckers, voids or breaks are introduced and that overlap is maintained.
Inspection of Pipe Wrapping
Pipes and fittings shall be visually examined. Any defective or damaged wrapping shall be repaired or replace. Replace shall be carried out in accordance with manufacturer’s recommendations.