Wet services water


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Wet services water

  1. 1. Wet servicesWater supply and drainage
  2. 2. Fundamental source of modern standards of public health• Water supply: – Public mains – Private boreholes – Private reservoirs• Drainage: – Domestic drainage – Public sewerage and waste treatment – Private sewage treatment
  3. 3. Sources of water • Public supply: – Large reservoirs at high level – Direct extraction from rivers – Direct extraction from aquifers via boreholes • Private supplies – Boreholes/wells for drinking water – Private reservoirs for irrigation water Reservoir/lake Borehole/well RiverAquifer
  4. 4. Water distribution• Water moved from source to outlet by gravity when ever possible.• Water moved from primary source to local reservoir/water tower storage for local distribution• Water treated by filtration, aeration and chlorination. Fluoridation controversial, but proved to aid tooth health.
  5. 5. Local water distribution • Groups of buildings supplied from a local reservoir or water tower • Pipes under ground for mechanical and frost protection • Pipes laid in a grid linked to more than one supply to aid continuity of supply Local tower Local reservoirMain supply
  6. 6. Water supply information• Water supply pipes are now made of high density polythene and are buried at least 0.75m below ground for protection• Older pipe work is steel, iron and lead. Its replacement is a major industrial cost• Up to 25% of water is lost through supply pipe leakage
  7. 7. Hard and soft water• Water from areas of limestone or chalk are likely to be “hard”• Water from areas of granite or sandstones are likely to be “soft”• Hard water contains calcium salts. These are if anything beneficial to health, but they can • Water softeners replace precipitate out, causing calcium salts with sodium “furring” of pipe work salts. with lime scale • Sodium salts do not• Calcium salts also precipitate but can be a interfere with the action health problem for people of soaps with high blood pressure • Softened water should not be used for drinking water. • Naturally soft water is perfectly safe
  8. 8. Domestic water supply 1: entry of water supply
  9. 9. Domestic water supply 2: rising cold water mainOverflow to Cold water storagenoticeable tank. Float valve stopslocation over filling “Rising main” inside the building for frost protection Position of water softener (if fitted) Direct feed to Water kitchen for company drinking stop tap
  10. 10. Internal water pipework• Internal water supply pipes generally made of copper – Corrosion resistance – Ease of jointing• Pipes and fittings like taps can be joined by – screw compression fittings, strong but expensive – Soldered fittings, much quicker and quite adequate if well made
  11. 11. Compression joints and soldered joints
  12. 12. Domestic water supply 3: cold water distribution Stored cold water supply pipe Feeds to upstairs sanitary unitsFeed to Feeds tobottom of hot downstairswater storage sanitary units,tank but not to kitchen sink
  13. 13. Domestic water supply 3: cold water distributionCold tank is kepton warm side ofroof insulation Stored cold water supply pipe Feeds to upstairs sanitary units Feed to Feeds to bottom of hot downstairs water storage sanitary units, tank but not to kitchen sink
  14. 14. Hot water distribution Safety expansionHot water out at pipe rises abovethe top of the hot tankwater tank Hot water to Cold water in at first floor the bottom of the hot water tank Hot water to ground floor
  15. 15. Hot water distribution Safety expansionHot water out at pipe rises abovethe top of the hot tankwater tank Hot water to Cold water in at first floor the bottom of the hot water tank Hot water boiler Hot water heating tank water to ground indirectly. Should floor be fitted with safety expansion valve
  16. 16. Hot water, cold water and central heatingSafety expansion Header tank topipes keep heating system full of water Pumps to force heating water around the system Rotary valve directs water from boiler to radiators
  17. 17. Final points on water supply• All fittings should have their own isolation valves so they can be removed without draining the system• All pipework should be ventilated to a high point for safety• There must be a drain point at all low points in the system• All pipework must be protected from freezing