Er.Gokul.A,Civil 3rd year ‘B’ sec

Periyar Maniammai University,Vallam.

Pipe Lines in Sewage system

One Pipe Line System

Two Pipe Line System

Single stack pipe line System

Partially Single stack pipe System

Four type pipe line systems :-

One Pipe Line System

In the system all soil and waste water discharge into one common pipe and all branch ventilating pipes into one main pipe.

This system largely replaces the two pipe system and lent itself very well to use in multistorey developments.

It is far more economical than the two pipe system.

One Pipe Line System

Advantages.Largely replaced two pipe system in most developed

countries. Fast becoming preferred system in other parts of the

world.High quality pipes, fittings and installation techniques

available these days.Constant flow of water ensures reduction in blockage

problem.Eliminated gully traps. Thus precludes the need to

clean them.Highly economical in terms of cost.Quick to construct and commission.Disadvantages.Danger of back flow of sewage in waste fittings.

One Pipe Line System

Two Pipe Line System

The Soil stack receives the discharge from soil appliances and delivered it direct to the underground drainage system

The waste and soil water did not combine until they reached the below ground drainage system.

Two Pipe Line System

Advantages

Ensure segregation of foul sewage from waste water.

No danger of backflow of sewage in waste fittings incase of blockage of soil pipe.

Enables use of waste water directly for irrigation/gardening.

Separate waste water stack permits arrest of solids from kitchen in the gully trap thus preventing the from entering sewer. Gully traps needs to be cleaned periodically.

Two Pipe Line System

Disadvantages

Difficult to install in high rise buildings where stacks terminate in service floor or in the ceiling of the basement.

Long horizontal runs to reach external walls /external sewers.

Provision of gully trap difficult to implement in above situation.

Require more shaft/duct space.

Single stack system

Only one pipe system without providing any separate ventilation pipe.

It carries both sewage and sullage waterThere is no vent pipeIt extended upto 2m to 3m higher than the

roof level and provided with cowl for foul gases.

Single stack system

Partially ventilated single stack system

This system uses 2 single stack pipes, one for waste and the others is for soil.

Both of the single stack pipes have individual ventilation system.

The waste discharge pipe drains waste water from the shower tray and bath tub.

The soil discharge pipe drains soil water from the WC and urinal.

The single stack pipe is then connected to the underground drainage pipe.

Partially ventilated single stack system