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Defects
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Probable causes for the defect
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Design for Maintainability (DfM) Guidelines
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Leakages
 Corrosion leading to leakage  Sanitary pipe leakage |
- Joining pipes of different material without adaptor.
- Absence of elastomeric seal at joints or sleeve at slab / wall penetrations.
- Poor workmanship at joints. Not even tested to rectify.
- Corrosion – unsuitable material or damaged coating.
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Design
Construction
Maintenance
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| Slow / no discharge |
- Inadequate gradient of branch pipes.
- Dirt entering through damaged / removed floor trap.
- Solid construction waste clogs the pipes.
- Irregular / inadequate cleaning especially if accessibility is poor.
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Design
Construction
Maintenance
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| Discharge of foul air into the building |
- Non provision / wrong design of ventilating pipe.
- Trap seal loss of fixtures for waving out (pressure fluctuation) for short / straight vent.
- Induced siphonage due to absence of trap ventilating pipes
- Self siphonage of undersized discharge stacks.
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Design
Construction
Maintenance
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| No access for maintenance |
- Mismatched position of access cover / cleaning eyes and pipe joints
- Pipes covered by building elements.
- Pipes laid with inadequate clearance from structure.
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Design
Construction
Maintenance
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References
[1]
Normative References/Standards Referred to for Air Handling Unit and Fan Coil Unit