ABSTRACT
A tempering valve can be used to provide a simple means for temperature control of potable hot water distribution to several sanitary fitments. To prevent an excess of water use and unnecessary waste, most sanitary appliances are fitted with a means for plugging the waste outlet. The valve can be set manually where precise temperature control is not a requirement, but where used to supply sanitary appliances an anti-scald protection measure by automatic thermostatic control set to a maximum of 48°C will be necessary. Foul air from the drain and sewer is prevented from penetrating buildings by applying a water trap to all sanitary appliances. The ventilated stack system is used in buildings where close grouping of sanitary appliances occurs – typical of lavatories in commercial premises. The collar is in effect a gallery with purpose-made bosses for connection of waste pipes to the discharge stack without the problem of cross-flow interference.
