Section 126 in West Bengal Municipal (Building) Rules, 2007
126. Syphon-trap and Anti-syphonage Pipe.
(1) Every connected privy and connected urinal shall be provided with a syphon trap which shall be proof against syphonage.(2)In all cases where a connector privy or connected urinal is more than one storey high, an anti-syphonage pipe having an internal diameter of not less than fifty millimetres shall be provided, and such pipe shall be carried independently to a height of at least sixty centimetres above the roof of the privy or urinal or the roof of the building in which such privy or urinal is situated.(3)No 'container' or other similar fittings shall be placed under the pan of a connected privy or connected urinal and no trap of the kind known as a 'D trap' shall be used with any such privy or urinal.
