CONTENTS
1.0 PURPOSE
2.0 SCOPE
3.0 REFERENCES
4.0 DEFINITIONS
5.0 RESPONSIBILITIES
6.0 EQUIPMENT
7.0 PROCEDURE
8.0 ATTACHMENTS
1.0 PURPOSE
This method statement is applicable for Installation & testing of Domestic Cold and Hot water supply Piping system and its accessories ( Above & Below Ground) in all areas for the project.
2.0 SCOPE
Supply , installation & testing of Domestic Cold and Hot water supply Piping system and its accessories (Above ground & Below Ground) for all applications in line with project requirments.
3.0 REFERENCES
- Latest Approved shop drawings for the water supply system.
- Specifications
- Project Quality Plan
- Material Submittal Approvals
4.0 DEFINITIONS:
- PQP : Project Quality Plan
- PSP : Project Safety Plan
- HSE : Health, Safety and Environment
- MS : Method Statement
- ITP : Inspection Test Plan
- QA/QC : Quality Assurance / Quality Control Engineer.
- WIR : Inspection Request
- MIR : Material Request
- PP-R pipe : Polypropylene random copolymer (PP-R), PN-20 to DIN 8077 and 8078 for sizes up to 4″ diameter for above grade.
- PEX Pipe : polyethylene cold and hot water pipe installed inside the Toilets DIN16892/93.
- PE 100 pipes : Polyethylene SDR 11 Domestic cold water pipes for below grade installation.
- PRV : Pressure Reducing Valve.
5.0 RESPONSIBILITIES:
Responsibilities for ensuring that the steps in this procedure shall be carried out are specified at relevant steps in the procedure:
5.1 Project Manager
The work progress shall be carried out as per planned program and all the equipment’s required to execute the works shall be available and in good condition as per project planned.
Specific attention is paid to all safety measures and quality control in coordination with Safety Engineer and QA/QC Engineer and in line with PSP and PQP.
5.2 Construction Manager
Construction Manager is responsible to supervise and control the work on site.
5.3 Site Engineer
The method of statement to the system shall be implemented according to the Consultant project specifications and approved shop drawings.
Provision of all necessary information and distribution of responsibilities to his Construction team.
The work progress shall be monitored in accordance with the planned work program and he will provide reports to his superiors.
The constant coordination with the Safety Engineer to ensure that the works are carried out in safe working atmosphere.
The constant coordination with the QA/QC Engineer for any works to be carried out and initiate for the Inspection for the finished works.
He will ensure the implementation of any request that might be raised by the Consultant.
Efficient daily progress shall be obtained for all the equipment and manpower.
He will engage in the work and check the same against the daily report received from the Foremen.
The passage of all the revised information to the Foremen and ensure that it’s being carried out properly.
5.4 QA/QC Engineer (MEP):
The monitoring of executions of works at site and should be as per the approved shop drawings and project specifications.
Ensure WIRs and MIRs are being raised for activities in timely manner and inspected by the Consultant.
He will follow and carried out all the relevant tests as per project specifications.
Obtain the required clearance prior to Consultant’s inspections.
Should acquire any necessary civil works clearances and coordination.
5.5 Site Foreman
The carrying-out of work and the proper distribution of all the available resources in coordination with the Site Engineer on a daily basis.
Daily reports of the works are achieved and coordinated for the future planning with the Site Engineer.
Incorporate all the QA/QC and Safety requirements as requested by the concerned Engineer.
Meeting with any type of unforeseen incident or requirement and reporting the same to the Site Engineer immediately.
5.6 Safety Officer
The implementation of all safety measures in accordance with the HSE plan and that the whole work force is aware of its proper implementation.
The implementation of safety measures is adequate to maintain a safe working environment on the work activity.
Inspection of all the site activities and training personnel in accident prevention and its proper reporting to the Construction Manager and the Project Manager.
The site is maintained in a clean and tidy manner.
Ensure only trained persons shall operate the power tools.
Ensure all concerned personals shall use PPE and all other items as required.
Ensure adequate lighting is provided in the working area at night time.
Ensure high risk elevated areas are provided are barricade, tape, safety nets and provided with ladders.
Ensure service area/inspection area openings are provided with barricade, tape, and safety nets.
Ensure safe access to site work at all times.
5.7 Store Keeper (SK)
Responsible for overall Store operations in making sure to store the material delivery to the site and keep it in suitable area that will keep the material in safe from rusty and damage.
6.0 EQUIPMENT
Following tools shall be arranged before starting the job.
| Tool box | Anchor punch | Pipe wrench |
| Measuring tapeTest Plug | Marking line-doriManual Pump | Electro fusion machine for PE Pipes( HDPE) |
| Marker | Screw driver (flat & star set) | PP-R cutter |
| Wood-saw | Fix spanner (4mm to 32 mm) | Testing pump |
| Half round file | Adjustable spanner | Steel cutter plier |
| Hack-saw frame | Monkey plier | Teflon tape. |
| Hilti drill machineFusion machine for PPR pipes | Electrical plier | Scaffolding/Ladder |
7.0 PROCEDURE
7.1 Work Sequence
- Check all material delivered to site is inspected properly by QA/QC Engineer and check if it is stored properly as per manufacturer’s recommendations.
- MIR shall be raised for the inspection of All pipes and fittings received at site to the Consultant Engineer.
- Work shall be carried out by the site staff under strict supervision and guidance of the concerned Supervisors / Foremen / Engineers.
- The MEP QA/QC Engineer shall check all the installations as per the Installation Check list.
- WIR shall be prepared by MEP QA/QC Engineer and will be submitted to Consultant for their inspection and approval.
- MEP QA/QC Engineer shall coordinate with other contractors and arrange inspection for installation to the CONSULTANT Engineer.
7.2 Material Storage & Handling
All pipes shall be stored properly with end caps. The pipes shall be stored on a flat dry level surface free from sharp projections, stones or other objects likely to cause point loading or pipe deformation. Timber supports spaced 1.5m apart along the pipe can be used to support the pipes.
7.3 Sequence of the Installation
a. Ensure that all piping are installed as per approved material submittal and approved shop draings.
b. Mark routing of pipe work according to approved shop drawing.
c. Install fittings for changes in direction and branch connections with appropriate branches, bends and long sweep bends.
d. Check below the sequence of installation for all water supply pipe works.
7.4. Sleeves and Puddle Flange Installation:
7.4.1 Sleeves installation procedure:
- As per approved shop drawings and Invert Level, mark the centre and invert level of Sleeve on reinforcement /steel bars for water walls.
- Steel fixing contractor to bend and clear the exact area for installing Sleeve.
- Once the location is clear, position the Sleeve in the steel area.
- Once the Sleeve is in proper location recheck the level and alignment.
- Tie the sleeves with suitable wires with steel to avoid any misalignment while concreting.
- Clearance for civil contractor to close the shutter with exact holes matching with Sleeve to proceed with concrete pouring.
- All the work to be inspected at all stages by consultant engineer as per attached in the check list.
7.4.2 Procedure Installation of Puddle flange for the water wall:
- As per approved shop drawings and Invert Level, mark the Centre and invert level of Puddle flange on reinforcement /steel bars for water walls.
- Steel fixing contractor to bend and clear the exact area for installing puddle flange.
- Once the location is clear, position the puddle flange in the steel area.
- Once the puddle flange is in proper location recheck the level and alignment.
- Clearance for civil contractor to close the shutter with exact holes matching with puddle flange to proceed with concrete pouring.
- All the work to be inspected at all stages by consultant engineer as per attached in the check list.
- The puddle flange to be applied by two coats bitumine as specified before installation.
7.5 Pipes & Fittings Installation Procedure
7.5.1. Domestic cold water below grade (PE 100 SDR 11 pipes).
- Make sure civil clearance is available for laying the pipe line in trench.
- Below ground water supply pipes shall be PE-100.
- Mark routing of pipe work according to approved shop drawing.
- Install any supports or spacers as required or as per the approved shop drawings and specifications.
- Lay the pipe according to the approved shop drawing.
- Install fittings for changes in direction and branch connections with appropriate branches, bends and long sweep bends.
- Reducing the size of piping in direction of flow shall be avoided.
- Provide thrust blocks for buried water mains, at every change in direction of the pipe, to resist the thrust due to the test pressure and unexpected surge during operation.Thrust blocks shall be poured against undisturbed soil.
- Pipes shall be joined using electrofusion process as mentioned in point 7.5.1.2.
- Plug all open ends of the pipe work.
- Flush all fluid-carrying systems after completion with a stream of water or appropriate fluid at the highest obtainable pressure and velocity. Discharge the flushing fluid through all strainers and out through line sized valves with hose ends. Clean all strainers. Repeat flushing operation to the approval of the CONSULTANT until the water is running clear, colourless and odourless.
7.5.1.1 Pipe Jointing For Below Grade Pipes
Below grade PE 100 pipes shall be joined using the electro fusion welding PN-16 as follow:
7.5.1.2 Steps of the electrofusion weld process:
1. Preparations
Good preparation consist of making sure the electrofusion control box works properly. The inserted pipe or fitting must completely cover the resistance wires at the surface of the coupler for a good heat exchange. In order to utilize the fusion and cold zones in the pipe or fitting must be inserted to the correct depth.
2. Cutting the pipe square
The pipe ends must be cut square to ensure that the resistance wire in the coupler is completely covered by the pipe or fitting.
3. Mark surface for scraping
The insertion depth +10 mm must be marked to ensure the oxidized layer will be removed from the full welding zone.
4. Scrape pipe and mark insertion depth
The full outer surface of the pipe that will be covered by the coupler, must be scraped (approx. 0,2 mm deep) to remove any surface ‘oxidation’. The insertion depth should be marked again to safeguard full insertion.
5. Clean electrofusion coupler
Before assembling the pipes into the coupler ensures that all surfaces are clean and dry.
6. Insert pipe/fitting until marked line
Ensure that the pipe is pushed into the coupler as straight as possible and up to the marked insertion depth. This will ensure that all the wires are covered with PE100 during the fusion cycle.
7. Prevent misalignment and movement
Misalignment will cause extra load on the fusion zone causing additional PE100 to melt resulting in the outpouring of PE100 pipe or wire movement. The movement of the pipe can cause melted PE100 to flow out of the joint. This can result in wire movement and possibly a short circuit and thus a bad weld or fire hazard.
8. Welding electrofusion coupler and cooling down
Commence welding after connecting the control box to the coupler by pressing the start button. Control boxes adapt the welding time to the ambient temperature. The joint assembly should not be disturbed during the fusion cycle and for the specified cooling time afterwards.
7.5.2 Installation of Domestic Hot & Cold Water Piping (Above Grade) – PP-R (PN-20):
- Ensure only approved drawings are used for installation.
- Mark the pipe routing on the soffit of slab or as required, duly coordinated with other services and as per approved layout drawings.
- Install hangers and supports with approved material.
- The spacing of the supports for the vertical and horizontal pipes shall be in accordance with the approved details drawings and standards as applicable.
- The pipes shall be installed at designated levels as per the coordinated layout.
- The pipes are cut to required length, and all sharp edges and burrs shall be removed.
- All safety measures to be taken for fusion welding of PPR.
- Use proper size of fusion weld bushes for jointing of PPR pipes and fittings while joining.
- Ensure manufacture’s recommended timing for heating and hand pressing.
- All valves shall be installed in an easily accessible location and adequate space shall be available for maintenance.
- Ensure that Air vents installed on all high points required for efficient operation and venting of system whether indicated on the drawings.
- PRVs will be installed as per manufacturer’s instructions at locations approved on approved shop drawings.
- Isolating valves shall be installed at all low points.
- Make sure that water hammer arrestor installed in all open circuit water system, in each branch connection and in each vertical branch on pipe run. It must be selected for Maximum working pressure 125 psi and Maximum temperature 300o F, and as per approved shop drawings.
- Make sure that the water meter installed as per manufacturer recommendation and as per approved shop drawings.
- Ensure that the Backflow preventers installed in horizontal or vertical position as per approved shop drawings.
- All pipe joints shall be left exposed until satisfactory completion of hydrostatic pressure testing as per point #. 7.6.
- The pipe work, valves etc., shall be identified as per specifications and manufacturer recommendations.
- Use crimping Tools in order to install the PEX pipes in the toilets embedded in the wall as follow:
- Cut the PEX tubing. Make sure you have a smooth and even cut. To achieve this, position the cutter at 90 degrees to the tubing as per below photo.
- Take the PEX crimp ring and slide it over the tubing approximately 2” past the end.
- Fully insert the PEX fitting into the PEX tubing in a way, so that the fitting’s shoulder touches the tubing.
- Position the PEX crimp ring 1/4”-1/8” from the end of the tubing. This way the crimp ring will be right above the PEX fitting’s barbs.
- Open the PEX crimp tool’s jaws. Position the PEX crimp tool over the crimp ring evenly, at 90-degrees to the tubing. Make sure that jaws of the tool are cantered over the crimp ring and it stays in place; Close the crimp tool’s jaws completely till the connection complete.
- Check the connection with a go-no-go gauge, to make sure that it was properly done.
- Then connect the pipe to the brass fittings as per approved shop drawings and specification.
- Make sure the installation of the PEX pipes to the Domestic Water heater done as per approved shop drawings and as per manufacturer recommendations.
7.5.3. Installation and Insulation of Cold Water Piping (in the Roof Area):
- Ensure all installation for the pipes in the roof as per approved shop drawings.
- Ensure civil clearance for all work in the roof area before starting the installation.
- Ensure that pipes runs with no clashes with other services.
- Make sure that Cold water services pipework installed on roof shall be insulated with preformed sections of aluminium foil faced rigid fibre glass insulation, minimum density 2 inch 65 Kg/M3, and covered with Aluglass Cloth backing (18u / FR Glue / 8×8 Mesh Aluglass Cloth), combined with a high performance flame retardant solvent acrylic adhesive, protected by an easy-release silicone release paper.
- Expansion loop and Expansion compensators shall be used for the network as per thermal expansion.
- All insulated pipework installed on roof, within plant room and wherever exposed to view shall be cladded with plain aluminium sheets at least 0.7mm thick.
- Insulation thickness shall be as follows:
Pipe Size Insulation
MM thickness (MM)
Up to 28 25
35 to 50 40
Above 50 50
7.6 Hydrostatic Test:
- Upon completion of installation, the open ended pipes shall suitably be plugged or blanked-off.
- All the joints shall be left uncovered until satisfactory completion of testing.
- Connect a calibrated pressure gauge to the pipe work at a suitable location.
- Check and ensure all drain valves are closed and in-line valves are open.
- Fill the section of pipe work under test with clean water.
- Subject the Cold & Hot Water piping to hydro test at 10 Bar Pressure for 24 hours of 1.5 times of the working pressure, whichever the highest by using a mechanical hand pump.
- After pressurizing the pipe work to the required pressure, a holding time of 2 hours shall be allowed.
- Inspect all joints, valves, fittings etc. for leaks, if there is a drop in pressure.
- Repair leaks and defects, if any, with new material as required and retest the pipe work until satisfactory results are obtained.
- Consultant/Consultant shall be notified at least 24 hours in advance to witness the test by submission of work inspection request.
- Only calibrated pressure gauge shall be used for pressure testing.
- All underground piping shall be tested in accordance with the manufacturer’s test pressures, before back filling can commence the same to be available during the said testing.
7.7 Testing and Commisssiong of the Water supply system
- After the piping network is finally approved the flushing and disinfection shall be done.
- Where pressure testing is specified in the contract documents this shall be undertaken using water pressure in accordance with the approved Specifications, provide and complete a signed record sheet for each pressure test for the contractors and consultant.
- Flush out all pipe work with clean water before commissioning.
- Check all isolating valves and float-operated valves for effective operation.
- Visually check all stem glands for leaks on all types of valves and drain cocks.
- Visually check for leaks, any pipe joints which were not subjected to a pressure test.
- Check that all pipeline strainers and outlets strainers are free of deposition before completing the commissioning procedure.
- Prior to the handover of the work, complete any commissioning check list document issued under the contract or provided by an equipment manufacturer and hand over to the main contractor.
- The samples will be taken and tested from the third party as per Consultant requirement.
7.8 Commissioning and Testing of Water Tanks
8.0 ATTACHMENTS
8.1 Inspection & Test Plan
8.2 Check Sheets
8.3 Rik Assessment
