1. Cold water supply and Treatment
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2. Objectives
State the regulations and the purpose of the regulations covering cold-water
Describe how water is collected, stored and distributed.
Describe the cold water service from mains to a dwelling (including water meters)
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3. Standards and Regulations
What is the main British standard detailing installation of Hot and Cold supplies?
BS 6700
Others
BS : Workmanship for Hot and Cold supplies
Water Regulations
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4. In chemical terms water is a compound of two gases : Hydrogen and Oxygen H20
Water has solvent power according to the strata or ground it passes through.
Soft water, easy to produce a lather, doesn’t contains salts such as calcium carbonates or sulphates
Hard water difficult to obtain a lather, does contain salts such as calcium carbonates and sulphates
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5. How is hardness classified?
Water is classified by the number of parts of calcium per million parts of water
Soft water 0 to 50
Moderately soft 50 to 100
Slightly hard 100 to 150
Moderately hard 150 to 200
Hard 200 to 300
Very hard over 300
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6. Permanent or Temporary Hard?
Temporary hardness leaves lime scale deposits on the inside of pipes and plumbing systems.
Permanent hard occurs when water dissolves sulphates of limestone.
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7. The water cycle
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8. Wells There are three types of wells What type of well is this?
A shallow well
Does not penetrate the impervious strata
What class is the water
Water is classified as dangerous
Pervious
Impervious
Pervious
Shallow well
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9. Wells What type of well is this? Deep well
Penetrates the impervious strata
What is water classed as
Water is classed as wholesome
Pervious
Impervious
Pervious
Deep well
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10. Artesian Well
Water Penetrates under
Impervious layer
Water Table
Pervious strata
An Artesian well is below the water table and the ‘head’ of water causes the water to eject under pressure
Impervious strata
pervious strata
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11. Summary of water source classification
Wholesome:
Spring water
Deep Well water
Upland surface water
Suspicious:
Stored rainwater
5 Surface water from cultivated land
Dangerous:
River water
Shallow well
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12. Is your water fit to drink?
Yes it is, but only after it has been through these processes:
Strained
Filtered
Chemically treated
Sterilised
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13. Water Distribution Reservoir Water Treatment Local Mains Trunk Mains
SUPPLY
Reservoir
Water
Treatment
Local Mains
Trunk Mains
Principle Mains
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14. End of Part One
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15. Cold water supply and Treatment 2
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16. Connections to water mains
Connection to main made with a ferrule whilst the main is still live via a “Wet Box”
Connections can only be made by the Water Undertaker, in this area Yorkshire Water
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17. How is the water service pipe connected to the water main?
Water mains are made from various materials
Steel
PVC
Cast – iron
PVC: is now used extensively on new installations and mains replacements
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18. Connection from main into building
Pipe or duct
Sealed at both
Ends to prevent vermin etc
750mm To
1350mm
Boundary
Gooseneck
Ferrule
main
Supply pipe
Communication pipe
Service pipe
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19. Key points about service pipes
Pipes to laid between 750mm minimum
1350mm maximum
More than this would prevent ease of access
Metal pipes should be protected against corrosion especially in acidic soils.
Use of plastic coated pipe
Wrapping pipe in anti corrosive tape
Install pipe in duct
Minimum size of service pipe is 15mm
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20. Key points about service pipes
If service pipes are laid on a ‘brownfield site’ (contaminated land)
Be manufactured from metallic material or plastics barrier pipe
Why?
To prevent contaminants from the soil permeating through the plastics material into the water supply.
Preferred location of isolation to whole of property
Above ground – immediately on entry to the building
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21. Key points about service pipes
Stop valve to BS 1010
Drain valve : Screwdown type conforming to BS 2879.
Pipe to be within duct at point of entry to dwelling
If pipe is installed less than 750mm from external wall then:
Insulated to a depth of 750mm
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22. Stop valve chambers Ease of access to stop valve
Minimum diameter of pipe:
150mm plastic pipe or earthenware
Sited on a firm base
Top to have stop valve cover
Usually made from metal
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23. External water meters
Now becoming more widespread on domestic properties
Meter pipes can be obtained pre-plumbed
Are adjustable
Top of meter to be no more than 300mm from lid
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24. Internal Water Meters
Water meters must have fittings to allow connection/disconnection without the use of heat
Must be able to be isolated
Have a permanent cross bond
Max 1.5m from floor level
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25. Internal Water Meters Cont’d
When a meter is fitted in an enclosure
Front of meter to be no more than 300mm from the front of enclosure
Enables reading of meter
Rules regarding connection as before
Permanent cross bond to be fitted.
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26. End of lesson
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