Enhancing Interpretability of Data-Driven Fault Detection and Diagnosis Methodology with Maintainability Rules in Smart Building Management

Table 8

Plumbing & Sanitary Systems - Water Supply System.

Problem	Design	Construction	Maintenance
Corrosion and scaling of pipe/valve; Scaling in pipe; Corrosion of pipe flange	Specify materials that are resistant to corrosion and non-reactive to the conveyed water and surrounding ground in a cadence with BS EN 545, BS EN 598 or equivalent, and that do not impart any taste or toxicity to the water in accordance with BS EN 1796, SS 375-1 or equivalent.; Use of single material for the entire system is preferable for easy connection/jointing. Specify pipe system material that does not react with the pumped medium.	Pipe penetrations and joints should strictly comply with manufacturer’s instructions.; Jointing material should not enter pipe. Caulking at penetration sleeve should be made watertight.; Proper installation should be fulfilled while ensuring that the protective coating is not lost/damaged during installation in accordance with BS 8558, SS 636 or equivalent.	Carry out quarterly chemical and bacteriological analysis of water used [10].; Perform monthly check of water supply for visual signs of leakage, scaling and corrosion of pipes, joints, valves, taps and mixers. Increase frequency of inspection for damp or polluted areas in accordance with BS 8554 or equivalent.; Carry out monthly inspections and clean off/remove any rust or scale. Re-paint parts in a timely manner if needed in accordance with BS EN 806-5 or equivalent.
Damaged piping; Burst outdoor pipe; Damaged outdoor pipes; Corroded galvanised piping	Pipework design should consider factors such as the choice of material, rate of flow, accessibility, protection against damage, corrosion, avoidance of airlocks, water hammers, noise transmission, unsightly arrangements, vibration and expansion of fluid, stress and strains, etc. in accordance with BS EN 1057, BS EN ISO 21003-2, BS EN ISO 21003-3, BS EN ISO 21003-5 or equivalent. Provide adequate longitudinal support to pipe installations below ground to cater for loads and traffic vibration.	For underground pipe laying, fully compact bedding prior to installation and maintain the correct depth of trench, gradient, width and bottom condition.; Properly align pipe work and use suitable joints. Ensure careful backfilling at an adequate depth for underground pipe laying. Completed sections should be tested for defects using leakage tests and should be rectified by the contractor as required. Maintain proper water pressure in piping system to avoid bursting from over pressurisation.	Carry out thorough cleaning and disinfection of service pipes on a monthly basis, and clean the main pipes semi-annually. If required, removal of blockage with manual cleaning method (e.g., plunger, drain rod, spring auger) should be performed.; Carry out chemical de-scaling quarterly (care should be taken so that it does not harm the pipes or jointing by giving consideration to chemical type or contact time). Perform maintenance schedule to check for clogged outlets in accordance with BS 8558, SS 636 [11].; Isolate all leaks and faulty water pipes and fittings first to prevent water wastage before they are being repaired by a licensed plumber. All repairs should be done as soon as possible.
Water hammer; Cast iron pipe cracked by water hammer; Thrust bearing of a submersible pump ruined by water hammer	Avoid water hammers (water pipe banging) in pipework design in accordance with JIS A 4422, BS EN 1057 or equivalent.; Design airlocks and low supply pressure to minimise turbulent flow.; Evaluate the required strength of valves and tightness of body and in between the inlet and outlet chamber in accordance with BS EN 1567 or equivalent.	Note that a water hammer may arise when the electric valves on appliances or single control valves are shut off fast. Although all noises due to water flow and pipe expansion cannot be removed, the contractor is responsible for fastening the pipes properly and commissioning valves/actuators to minimise the water hammer.; Install check valve to control the creation of a vacuum in discharge pipe in accordance with BS EN 16767, BS EN 545 or equivalent.	Monthly pressure test should be carried out by operating pump for min. 1 hr with 125 m head or 150% of working pressure (whichever is greater) and check for any individual leakage or overall leakage.; Semi-annual pressure test should be carried out for sewage pumps.; Additional bracing or anchor block support at bends and branches should be provided in order to withstand the hydraulic thrust.
Excessive vibration; Insufficient vibration damping causing wear-out of parts; Dented pump impeller	Ensure that pumps are properly sized to meet the required pressure. Head loss, frictional loss and loss at bends should also be considered.; Sewage pumps should be able to handle long and fibrous material. If required, pre-treatment (e.g., crushing) is provided.; Specify variable speed drives (VSD) that are able to handle both maximum and variable demand. Ensure that the pump is mounted on an isolation bed (e.g., 150 mm insulated padding) and that no site adjustment in height or position should be done.	The installation of pumps should be adopted in accordance with manufacturer’s instructions. Ensure proper construction of isolation beds and installation/mounting of equipment.; Special attention should be given for tightness of joints, and alignment of bearings and pipes.; Testing and commissioning of the auto and manual interchange of duty and standby pumps should be carried out.	Lubricate pump parts with oil or grease in accordance with manufacturer’s instructions.; Carry out routine checks, clean motor starter and all heavy current contacts, and replace worn parts.; Visually check for any damage or missing parts (screw, nuts, strainer, etc.).; Ensure that after installation, pump is tested with power on mode for any unusual vibration, noise, leakage or burnt smell.
Sensor self-closing delayed-action basin taps	To specify the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	To ensure the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	Carry out routine checks to ensure that sensor self-closing delayed-action tap can function properly and when the tap is activated, the water is automatically cut-off after a pre-set period of time. The tap should automatically stop functioning during power failure in accordance with SS 448.
Self-closing delayed-action basin taps	To specify the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	To ensure the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	Carry out routine checks to ensure that self-closing delayed-action tap can function properly and that the water is automatically cut-off after a pre-set time in accordance with SS448.
Dual-flush low-capacity flushing cisterns	To specify the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	To ensure the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	Ensure that flushing cistern can function properly in accordance with SS574 and check for signs of leakage, defect or damage (including any leakage, defect or damage at the outlet and inlet valves).
Sensor urinal flush valves	To specify the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	To ensure the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	Carry out routine checks to ensure that sensor urinal flush valves can function properly and discharge the flush volumes not exceeding those specified in SS 636.
Sensor WC flush valves	To specify the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	To ensure the display contact numbers of maintenance staff so that users can report any faulty, leakages or damaged taps to them for immediate rectification.	Carry out routine checks to ensure that sensor WC flush valves can function properly and discharge the flush volumes not exceeding 4.5 L per flush as specified in SS 636.