7.4.2.1.Connections to Sanitary Drainage Systems

(1) Fixtures shall be directly connected to a sanitary drainage system, except that (a) drinking fountains are permitted to be (i) indirectly connected to a sanitary drainage system, or (ii) connected to a storm drainage system, provided that where the system is subject to backflow, a backwater valve is installed in the fountain fixture drain, (b) drainage pans on heating/cooling units are permitted to be connected to a storm drainage system, provided that where the system is subject to backflow, a backwater valve is installed, (c) a floor drain is permitted to be connected to a storm drainage system, provided it is located where it can receive only clear-water waste or storm water, (d) fixtures or appliances that discharge only clear water waste are permitted to be connected to a storm drainage system or be drained onto a roof, and, (e) the following devices shall be indirectly connected to a drainage system: (i) a device for the display, storage, preparation or processing of food or drink, (ii) a sterilizer, (iii) a device that uses water as a cooling or heating medium, (iv) a water operated device, (v) a water treatment device, (vi) a drain or overflow from a water system or a heating system. (2) The connection of a soil or waste pipe to a nominally horizontal soil or waste pipe or to a nominally horizontal offset in a soil or waste stack shall be respectively at least 1.5 m measured horizontally from the bottom of a soil or waste stack or from the bottom of the upper vertical section of the soil or waste stack that, (a) receives a discharge of 30 or more fixture units, or (b) receives a discharge from fixtures located on 2 or more storeys. (3) No other fixture shall be connected to a lead bend or stub that serves a water closet. (4) Where a change in direction of more than 45° occurs in a soil or waste pipe that serves more than one clothes washer, and in which pressure zones are created by detergent suds, no other soil or waste pipe shall be connected to it within a length less than (a) 40 times the nominal pipe size of the soil or waste pipe or 2.44 m maximum vertical, whichever is less, before changing direction, and (b) 10 times the nominal pipe size of the nominally horizontal soil or waste pipe after changing direction. (See Note A-7.4.2.1.(4)) (5) Where a vent pipe is connected into a suds pressure zone referred to in Sentence (4), no other vent pipe shall be connected to that vent pipe within the height of the suds pressure zone. (See Note A-7.4.2.1.(4))