Type of Building
Storage in Litres
Dwelling houses & flats per residents
Hostels per residents
Hotels per residents
Offices without canteens per head
Offices with canteens per head
Restaurants per head/per meal
Day schools per head
Boarding schools per head
Nurses’ homes & medical quarter per residents
Type of Appliances
Rate of Flow (litres/s)
W.C flushing cistern
Wash basin with spray taps
Shower (with nozzle)
Sink with 13mm taps
Sink with 19mm taps
Sink with 25mm taps
- British Standard Institute BS 3402 (Quality of Vitreous China Sanitary Appliances)
- BS 3505 (Unplasticized Polyvinyl Chloride Pressure Pipes for Cold Portable Water)
- BS 4514 (Unplasticized PVC Soil and Ventilating Pipes)
- The National Plumbing Code
- Uniform Plumbing Code
- Code of Practice 304, 1968
- The pipe work layout was drawn on the building plan
- The appropriate demand units, DU, for each sanitary fixture was indicated on the layout.
- The sum of all the demand units were calculated along the pipe work to the source which in this case is the overhead storage tank.
- The demand units were converted into flow rates and recorded accordingly using a pipe sizing chart.
- The head of water H, in meters, was determined for each floor.
- The Equivalent length, EL, of the pipe run to each floor was determined. This was approximated as the measured length plus 30 % to account for the frictional resistance of bends, tees and other fittings in the pipe work.
- Determine available pressure loss rate, H/EL.
- Determine the index circuit. This is the pipe circuit with the lowest H to EL ratio.
- With the DU known, this was converted to flow rate using the pipe sizing chart.
- Armed with H/EL (converted to kPa), the chart was used to select pipe sizes.