Section 126(2) in West Bengal Municipal (Building) Rules, 2007
(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.
