Two Pipe System

• This system is used for connection of soil (WC and urinal ) and waste ( basin , bath , sink ) appliance separate stacks . 
• The trap on each appliance is fitted with vent pipe . 
• Individual vent pipes combine in a common vent for the range , which is inclining until it meets the vertical vent stack . 
• This vent stack may be carried to outside air or it may connect to the discharge stack at a point above the highest appliance . 
• The base at the vent stack should be connected to the discharge stack close to the bottom rest bend relieve any compression at this point . 
• This system is relatively expensive to install 
• It may also be used where the sanitary appliances are widely spaced or remote.