Principles of Plumbing Services in Buildings

     Plumbing services is the whole system of piping, fixtures, applications for providing water supply or drainage to the buildings with the use of pipes, control valves, pipe layouts, storage tanks, etc.

Collection and disposal of wastewater with the use of water closets, urinals, traps, vents, anti-siphonage pipes, house sewers, house drains, etc. have to be separately deal carefully for hygienic conditions.

Principles of Plumbing Services

The following factors are to be viewed while designing plumbing services to buildings:

  •  The possible passages of gases, the odour of vermin from pipes and sewers into the building should be prevented.
  •  The foul and waste matter should be removed from buildings as quickly as possible.
  •  The drainage pipes used in plumbing systems should be airtight, gas-tight and tough enough and durable to withstand the corrosive action of liquid wastes.

Plumbing Tools

  •  Water supply and drainage pipe joints should be leak-proof, strong and durable.
  •  The whole network of pipes used in plumbing services should have ample means of cleaning and removing barriers.
  •  Proper care has to be taken to check and rectify all possible air-locks, siphonage, under deposits and obstructions.

Pipe Layout Principles

The following rules should be used while laying of water supply lines:

Ensure that there should not be any cross-connection and backflow. Backflow can be eliminated by

-  Providing an adequate air gap between the inlet and final flood level in all places, particularly washbasins.

The inlet and float valve should be well fixed while connecting cistern to the water closet.

Positive tension at the outlet pipes should always be ensured.

Pipe Layout example inside Buildings

     Distribution line planning should be in such a way that it is easily accessible for inspection, replacement and repairs. Water supply pipes and Drainage pipes should not be laid very nearby to each other, especially drainage stoneware pipes. Ensure that water supply pipes should not be laid adjacent to the pipes carrying filthy water.

GI pipes should not be buried, as they tend to deteriorate in contact with soils. All pipes, including PVC pipes, should be tested for leakage and set inside the building as concealed pipes.

Determination of Pipe Sizes

     Generally, for a middle-class house, the average number of pipes used is about 8 of minimum nominal size 20 mm diameter are enough. For Water Closets which are directly connected to overhead tanks, a 25 mm diameter is enough to get ample flow.

Different Pipe Sizes used in plumbing

Minimum recommended size of pipes for different purposes like for Lavatory, Water close (tank type), drinking fountain - the diameter of pipe should be 10 mm and for bathtub, shower stand, and the kitchen sink - 12 mm and for service pipe - 20 mm and for Water closet (Valve type) - 25 mm.

A gate valve or stop valve must be fixed in an accessible place to control the output from overhead tanks and also to stop the water during repairs. For multi-storey buildings with many flats, a more complex arrangement of water distribution system should be adapted for uninterrupted water supply.

Layout of Building Drainage

The following are the important factors to be considered in the design and construction of drainage layout:

     The layout should be simple and laid in straight lines both in horizontal and vertical directions. There should not be any abrupt changes in the direction of a pipeline which may affect the natural flow.

Layout of Building Drainage

To ensure a gradual and smooth flow, the contained angle between the intersecting pipes should be less than 45°. At the points of intersection of pipes or wherever bends occur, it is necessary to provide inspection chambers.

Drainpipes should not be laid under a building. If it is unavoidable, a cast iron pipe can be laid in straight with a uniform gradient. Man uses water for a variety of purposes.

     Disposal of wastewater, that is, used water from the kitchen, toilet, cleaning has to be dealt with carefully as they are essential elements for the human beings to live in a house with minimum comfort. Plumbing services provide water supply or drainage to the building with the use of pipes, control valves, pipe layout, storage tanks, etc.