Below is a brief method statement that covers installation of water feature equipment’s and accessories, in accordance with project specifications and manufacturer’s installations.
MEP project manager, engineers site supervisors shall have overall responsibility for adherence to the approved method statement, project quality and site safety plan. They shall ensure that adequate resources and personnel are provided to perform the activity safely and as planned. Ensure that all necessary items of safety equipment’s and PPE are available prior to commencements of the water feature installation activity.
Site health & Safety Incharge shall enforce compliance to applicable legislation, health & safety plan and requirements of the approved method statement and risk assessment for the work activity. He shall undertake the routine inspections of work site and will enforce all relevant HSE requirements, safe working practices and applicable legislation. He shall prepare and present toolbox talks to all workers involved in activity in their own language, or by use of translators. He is authorised to stop the installation works whenever an unsafe condition is identified or suspected, or if the operation is inconsistent with the plan or method statement.
Project QA/QC engineer shall ensure that the requirements of this plumbing and landscaping method statement are adhered to during the execution of the installation activity on site. He shall ensure that the material delivered for installation and used during the activity comply with the requirement of the contract specification and are as per the approved and submitted material submittal. Quality engineer is responsible to implement the requirements of the inspection and the test plan for this activity and to ensure that works are inspected and checked internally before submitting to the consultant for inspection. He shall make sure that material submittals and shop drawings are approved by consultant and MIR is raised for consultant approval before using the water feature piping and accessories material on the site. He shall enforce the required inspection procedures and requirements and coordinate with the main contractor during all inspection activities and to provide the correct notice for inspection of the works.
Material Storage and Handling
On receipt of the material at the site, necessary precautions shall be taken for unloading, shifting & storage as follows:
All materials received at the site shall be inspected by consultant to ensure that the materials are as per approved material submittal through material inspections.
Any discrepancies / damage found will be notified and reported for further action. Material found not suitable for the site use will be removed from site immediately.
Material shall be stored in a covered and dry space at all times.
Provide factory supplied plastic end caps on each end of the pipe to prevent pipe ends damage and to avoid ingress of dirt and moisture accumulating inside the pipe.
Pre Installation Checks
Main contractor shall handover the area for installation to MEP contractor and make sure that all the activities of proceeding trades have been completed.
Coordination for locations and elevations has been carried out and all the gridlines and benchmarks are clearly marked. Check the dimensions of the structural openings are as per provided builders work drawings and are sufficiently sized to accommodate all the pipe works for system that will be installed.
Ensure that all safety requirements are in place in accordance with project safety plan, including relevant permits of work. All ladders and scaffolding to be used must be properly erected as per manufacturer’s recommendations and must be inspected by safety officer or competent person.
Check and ensure that all the tools are having the required certificates.
Ensure that pre-installation conference is done with the consultant & notification to start work is issued to the consultant.
Safety barricades must be installed around the structural openings and warning signs must be provided for safety measures.
Necessary permits and tool box meetings shall be made before proceeding with the water feature piping installation.
Ensure that the installation area is cleared and cleaned from foreign debris.
Make sure that all operatives are aware of correct material handling and installation procedures to ensure best quality of workmanship.
In addition wherever required, operatives are certified and competent to perform that activity on the project, and aware of the safe working requirements contained within the documents and associated risk assessments.
All necessary working permit shall be acquired prior the starting the activity which the permits will be applied for. Openings or penetration covers will not be removed until permits are received from safety departments.
Exclusion zones shall be provided, if required, to control the work area where required watchman will control exclusion area.
Check the hand tools to be in good working conditions and is suitable for purpose.
Temporary supply for electrical tools must be arranged properly and make sure that wire connections are not loose or damaged.
Ensure the latest revision of the approved shop drawings is being issued for construction.
Temporary lighting and ventilation must be adequate on the working area.
Take care for the embankment fill and setting out of the area if working outside the building.
Installation of UPVC Pipes, MEP Fittings, Valves and Accessories
Experienced personnel will carry out all the installation work. UPVC pipe will be installed in accordance with approved shop drawings and manufacturer’s instructions.
All the access to the ceiling works area will be by means of mobile tower/scaffold and as per the requirements of risk assessment.
The scaffold must be erected by competent trained employee and then inspected by the competent person prior to use, and after every alternation, or if it remains in one position for a duration of 7 days.
Material must not be carried up by using the access ladder at any time.
Ensure that the work area is suitably cordoned off to prevent persons not involved in the activity from staying into work area.
Mark out the position for any support channel or bracket in accordance with shop drawing in reference from the approved support calculation by consultant.
Install hangers and supports with the approved material and calculations by consultant at the recommended intervals as per specifications and approved shop drawings and standards as applicable.
Additional supports and hangers shall be provided at concentrated loads such as valves, flanges and specialties and at change in direction.
Check the dimensions and elevation of the finished face of floor, walls and columns after the route of pipe is being coordinated with other services. Pipes shall be leveled correctly from finish floor level.
Pipes shall be installed with proper slop gradient requirements as per the approved shop drawings.
UPVC pipes and fittings will be bonded with PVC cleaner followed with PVC cement.
See detailed procedure below for Solvent Cement Jointing Procedure.
Cut pipe square and de-burr after which the joining surfaces have to be cleaned an dried.
Apply cleaner to socket and pipe surface equal to the socket depth.
Apply without any delay, PVC cement in even layer on to both the surfaces.
Assemble the piping while cement is wet.
Ensure pipe bottoms into fitting socket and twist 1/8 to l/4 turn.
Hold for 30 seconds and allow for initial set, wipe off excess cement.
Allow 3 minutes for good handling strength and 30 minutes cure time for pipes 2″ and below. Longer cure time (approx. 1 hour) is to be allowed for larger diameter pipes.
Pipes shall be installed true to the line and to consist gradient.
All vertical pipes work shall be perpendicular and branches and changes in direction adequately supported.
No offsets shall be included in vertical stacks except where indicated or will occur in the ventilating section of the stack.
The requirement for additional offset shall be agreed with the consultant.
Wall penetration for horizontal connection shall be covered by the GI sleeves with non combustible materials and fire stooping sealant as required.
All pipes that will penetrate fire compartment walls or floors, a proprietary in tumescent fire collar shall be installed on the pipe to maintain the integrity of fire barrier.
Locate valves required for control, flushing or isolation of any part of water feature mechanical system in an accessible position.
All valves must be supported by hanging support system both sides of valves. Ensure that weight of the valves should not be on the pipes.
For all valves necessary identification information will be engraved on white plastic labels tied with stainless steel or brass chains as per the approved by consultant.
Suitable and approved expansion coupler shall be provided in all pipes passing through expansion joints.
The installation of all the fittings and pipes will be continued with the pipe installation as per approved drawings and materials.
Care shall be taken to prevent the introduction of dirt, debris and rubbish into the system and open ends of pipe works not being worked on shall be protected at all times by means of proprietary purpose made caps and plugs. Rags and paper shall not be used at any time for this purpose.
All piping will be identified with approved identifications, i.e. adhesive and color directional labels as per the project specifications.
Work inspection request for the installation shall be raised to consultant for approval.
Apply pressure test at 3 bars for 24 hours and obtain final approval from consultant.
All MEP fittings inlets, drains, overflows and nozzles shall be installed as per the approved material inspected by consultant.
Location and quantity of all MEP fittings inlets, drains, overflows and nozzles shall be as per the approved shop drawings and specifications and must be approved by the consultant.
Once everything is installed, the complete system will be presented for the approval from consultant.
Pipe Pressure Testing Procedure
Upon completion of installation all the open ended shall be suitably be plugged or blanked-off.
All piping before testing shall be plugged, fixed and anchored.
Levels and slopes also shall be checked and approved by the consultant according to the drawings and specifications.
All the joints shall be left uncovered until satisfactory completion of pressure testing.
Flush the sections of pipe works under test with water.
Connect the calibrated pressure gauge to the pipe work at the suitable location / test points.
Check and ensure all drain valves are closed and inline valves are open.
Fill the sections of pipe work under the test clean water. Leaving all high points open to allow for the purging of air.
Subject the piping to the static pressure of maximum 2 times above the operating pressure included as per design requirement, but not less than 1033 KPa (150 psi) test pressure by using a mechanical hand pump.
After pressurizing the pipe work to be required pressure, a holding time of 24 hours or as per manufacturer requirements and standard shall be allowed for leak test.
Inspect all joints, valves, fillings etc. for leaks if there is a drop in pressure.
Repair leaks and defects, if any, with new material are required and reset the pipe work until satisfactory results arc obtained.
After rectification, the test pressure shall be maintained for minimum period for 12 hours or as per manufacturer requirements and standards.
Work inspection request shall be raised to the consultants for the approval.
All initial and final reading for the testing shall be recorded on the test report sheet and kept for documentation purpose.
Photographs of the pressure testing must be taken for the documentation purpose.
After approval of installation and pressure test, cover the pipe lines embedded in block wall with concrete to protect the installation from any movements and damage from other trades.
Pipe lines under test are to be marked as “UNDER TEST” and other trades shall be informed.
Solvent Cement Jointing Procedure
Ensure good ventilation in the working areas. Forced ventilation should be used in confined spaces. Do not bring a naked flame close to the solvent cement operations. Spillage of solvent cement on the skin should be washed off immediately with soap and water.
Should the solvent cement get in the eyes, wash them with clean water for at least 15 minutes and seek medical advice.
Cut the pipe at right angle to the pipe axis using suitable sharp pipe cutter.
The pipe may be cut quickly and efficiently by Wheel-type plastic tubing cutter or Ratchet type cutters or fine tooth saws.
Remove burrs and filings from the outside and inside of the tube.
Clean the pipe and the fitting with dry cloth, in order to avoid any dust or sand that might affect the quality of the joint.
Clean the spigot and socket area with a dry cloth (natural fibers) to remove all dirt and moisture from spigot and socket.
Apply cleaner solution to the outside surface of the pipe and to the inside surface of the fitting.
Cleaner will prepare the surface for jointing for a better quality joint.
Using a suitably sized brush, apply a thin even coat of solvent cement to the Internal surface of the fitting socket first then to the pipe spigot.
Excess solvent cement must be avoided as pools of solvent cement will continue to attack the PVC and weaken the pipe.
Excess solvent cement will accumulate inside the system and may cause a reduction in the joint cross section.
While both surfaces are still wet with solvent cement, Insert the pipe Into the fitting in a single movement.
Do not stop halfway, since the bond will start to set immediately and it will be almost impossible to insert further.
For a better distribution of the solvent cement, twist the pipe a 1/ 4 turn during insertion into the socket.
Wipe any excess cement from the pipe and leave the joint to dry completely.
Hold the joint for around 30 seconds, during which avoid applying any load on the joint in order to avoid reducing the strength of the joint.
Leave the system for at least 12 hours before filling with water.
At temperatures of 16°C and above, leave the system for 24 hours before pressure testing.
At lower temperatures, 48 hours is necessary before pressure testing.
Make sure that the end of each pipe is square in its socket and in the same alignment and grade as the preceding pipes or fittings.
Create a 0.5mm chamfer, as a sharp edge on the spigot will wipe off the solvent and reduce the interface area.
Do not attempt to join pipes at an angle. Curved lines should be jointed without stress, then curved after the joint is cured.
Previously cemented spigots and sockets be re-used. To repair a joint, cut out the defected joint and make a new joint.
Do not spill solvent cement onto pipes or fittings.
Accidental spillage should be wiped off immediately.
Threaded Jointing Procedure
Cutting of threads on PVC pipes is not an acceptable practice. Instead, moulded threaded adaptors should be used.
For threaded fittings, use Teflon thread-wrap tape in order to guarantee the water-tightness.
Grease or solvent cement should never be used on the threads.
Test the threaded parts before final assembly to ensure thread matching, particularly when connecting to other materials or to other manufacturers’ fittings.
The amount of Teflon tape should be judged accordingly.
The threaded Joints should be tightened initially by hand, and then a further two more turns should be sufficient to create a seal.
Note: Over tightening will over stress the fittings and could cause cracks and leakage.
When making a transition connection to metal threads, use male threaded adapter whenever possible.
This is necessary to avoid cracking the female uPVC fitting due to over tightening in presence of extra Teflon tape.
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