Before start of drainage system piping installation and testing completeness of the related works and systems shall be ensured by physical inspections and interpreting the previously submitted and approved work inspection reports/records.
Make sure that all tools/equipment/instruments required are calibrated and having valid certificate.
Safe access to work areas shall be provided and shall be approved by the safety person prior to commencement of drainage piping system installation works.
Temporary requirements to be arranged where required.
Below is the list of plant & equipment used for the work:
- Manometer
- Hand pump with T-piece connector and control valve
- Hose
- Bung stoppers
- 90 degree pipe bend
- 5-foot length of pipe
- Support struts
- Rope
- Water
Drainage System Pipe Installation
All piping shall be done in the best workman like manner in accordance with the best practices of the trade.
In accordance with the latest Codes of Practice there shall be no maximum gradient for soil and waste water pipe work.
No branch drains shall have a lesser grade than that for the main drain to which it is connected.
The piping shown on the drawings is diagrammatic for clearness in indicating the general run and connections and may or may not be, in all instances, shown in its true position.
Site plumbing engineer shall take responsibility for the proper erection of systems of piping in every respect suitable for the work intended and as described in the specifications.
All pipe ends will be plugged or capped all openings in pipe or fittings after installation.
Pipe Laying Procedures
The lateral connections from the concrete chambers toward the main vacuum line shall be laid with a minimum slope -0.2% in the direction of the flow.
Gate valve in the main line to be closed prior to connection of the lateral connections from the concrete manhole to the main vacuum line.
Y-branches shall be joined to the main line wherever house connections are coming. See the sketch provided.
Lateral house connection shall be fixed to the Y-branches.
Necessary inspections for alignment and levels shall be conducted and drainage piping works shall be approved.
Drainage Pipe Testing Procedure
Remove all obstructions, debris and superfluous matter from the pipelines
Secure all drain stoppers and/or bags in the end of the pipelines and all associated branches under test.
Fill water to the pipelines at least two hours before the test to allow for water absorption.
Record the test pressure at high end and low end upon test start.
Measure the loss of water inside the pipelines.
When a chemical cleaning agent is used to remove deposits of cement mortar from the surfaces of benching and channel inverts, protective clothing, including gloves and eye shields, shall be provided for operatives using or handling the chemicals.
On completion of the work, all treated surfaces shall be thoroughly hosed down.
When concrete bed, haunch and surround are used for the pipes, concrete work shall be complied with specifications.
Terminal manhole and invert levels shall be complied with requirements.
Test pressure of 1.5m head is applied at high end of the pipelines under test and is maintained for an interval of 30 minutes or otherwise as approved by consultant.
Testing & Commissioning of Pipes:
Immediately after construction is complete and final grade is attained, performance tests on the following items shall be provided by the us the MEP Contractor:
Piping: Piping shall be low-pressure air tested or vacuum tested in conjunction with the manhole vacuum test if desired.
Note: Any construction debris accumulated in new piping shall be removed and not permitted to enter pre-existing service lines.
The contractor shall notify the consultant of the time at which all tests are to be held and shall provide all the materials, labor and equipment required for testing.
Upon completion of the tests, copies of the complete records shall be given to the consultant for his retention in accordance with submittal procedures.
Contractor shall ensure the safety of the pipe work under test and shall be responsible for the pipe work and ancillary works during the test and shall replace or repair as directed by the Consultant, any pipe or fitting which in the opinion of the Consultant has failed to withstand the test will be rectified accordingly.
Drain Flow Test
A drain pipe test ensures the pipe is sufficiently watertight.
This prevents the pipe from leaking its contents into the surrounding soil and potentially overloading or contaminating the local area.
When laying new pipes, it is essential to test them before the trenches in which they are laid are backfilled with soil, as this saves a lot of time and effort in digging them back up again should they fail.
All drains will be tested for continuous and demonstrated for continuous flow verification
Air Testing of Drainage Piping
Clean the end of the pipe that will be tested to remove any dirt or other debris that could affect getting an air tight seal.
Place the bung stopper in the end of the pipe.
Turn the wing nut on the stopper until it cannot turn any more, to expand the stopper and create an air tight seal.
Seal off any branches on the pipe with more bungs.
Connect the hand pump to the hose via the T-piece connector.
Connect one end of the hose to the manometer.
Fix the hose nipple in place on the stopper in the pipe, to allow the hose to be attached.
Connect the free end of the hose to the hose nipple.
Squeeze the hand pump to increase the air pressure in the pipe until the level on the manometer reads between 5 and 6 inches.
Close the control valve on the hand pump.
Let the pipe stand for 10 minutes to level off temperature and pressure in the system.
Open the control valve and allow the pressure to drop so the manometer reads 3.93 inches.
Close the control valve again and leave the pipe for five minutes.
If after this time the pressure in the pipe has not dropped below 2.95 inches, the pipe is sealed correctly.
If the pipe fails this air test, run a water pressure test to check its seals again.
Water Leakage Test of Drainage System
Seal off all branches of the pipe with bung stoppers.
Seal off the lower, or downstream, end of the pipe to be tested with another bung stopper, as if creating an airtight seal.
Connect the 90 degree pipe bend to the other end of the pipe, which is the upstream end.
Connect the 5-foot length of pipe to this bend to create a vertical pipe configuration.
Either fasten this vertical section to your support struts with the rope, or brace it between two supports.
The idea is to prevent the pipe falling over under its own weight when water is added.
Fill the pipe with water and leave to stand for two hours to allow time for any trapped air to bubble out of the system.
Inspect the level of water in the vertical pipe and ensure it is to a depth of 4.92 feet.
Leave for 30 minutes, topping up the water as required maintaining a level of 4.92 feet.
Record the total amount of water added each time the pipe needs topping-up. Sum up these values. If the total is less than 0.88 pints per 3.28 feet of pipe, not including the 90 degree bend or the vertical pipe, the pipe has passed the water test.
If it exceeds this amount, the pipe is not watertight and the seals between each section of the pipe should be tested for integrity.
Sump Pump Testing & Commissioning Operation/Procedure
Mechanical Checks
Check and inspect the installation of Sump Pump is complete; verify the installation as per approved drawings.
Verify compliance to the manufacturer’s installation instructions for the sump pump.
Obtain installation certification from manufacturer or their authorized representative.
Check and ensure adequate clearance available for service and maintenance of pumps and motors.
Check the installation is coordinated with other services.
Ensure the shipping bolts / chambers are removed.
Check all nuts, bolts, screws, fasteners etc. are fixed and tightened as required.
Check the alignment is completed as per manufacturer’s instructions (where applicable).
Check and ensure the safety guards are in place and secure.
Rotate the pump manually and ensure free and smooth rotation.
Ensure the pumps are cleaned prior to start-up and all identification labels and tags are in place.
Electrical Checks
Check all power cabling and control wiring is completed and dressed neatly.
Check the power isolator is fixed close to the pump motor for emergency stop and power isolation.
Check all terminations are completed and tightened as required.
Check the grounding connections are completed and tightened as required.
Ensure the overload protections are set correctly as per the pump motor load current.
Ensure all identification tags and labelling works are complete.
Sump Pump Start-up and Testing
Check the line voltage and phase rotation before energizing the power.
Switch ON the power and start the pump and check the rotation is in the correct direction.
Immediately on start-up, check for any abnormal noise and vibration.
Rectify as / if required and consult manufacturer if required.
Observe for the correct operation of motor, pump and drive system.
Measure the current drawn (amperage) by the pump motor and record the same.
Record all pump and motor nameplate data in the commissioning format.
Ensure compliance to all manufacturers’ commissioning instructions, as applicable.
Tests and Inspections:
Perform each visual and mechanical inspection.
Leak Test: After installation, charge system and test for leaks. Repair leaks and retest until no leaks exist.
Operational Test: After electrical circuitry has been energized, start units to confirm proper motor rotation and unit operation.
Test and adjust controls and safeties. Replace damaged and malfunctioning controls and equipment.
Prepare test & inspection reports for consultant approval.
Housekeeping
All the off cuts of material will be collected and taken to the environmental waste separation area for recycling purposes.
Waste material will be forwarded to the recycling centre by environmental department workers.
All packaging materials will be removed from the site and always maintain safe and tidy workplace.
Any lubricants will be stored within a dedicated chemical store.
MSDS data must be available at all times for perusal by HSE manager, environmental manager and independent auditors.
Any chemicals used must formally assessed by manager sustainability prior to use on the site.
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