A Y-shaped plumbing fitting comprises three generally radially extending tubes connected together for transmission of fluid therebetween. The radially outward end of each tube is terminated by a pipe connector. The axes of the three tubes extend radially in a common plane and intersect at a single point, subtending angles of 120° with each other. A further connector is provided extending substantially perpendicularly to the common plane of the three tubes to connect a fitting to the three tubes. An irrigation system, using the Y-shaped plumbing fitting comprises a network of pipes connected by the “Y” shaped fittings. Each pipe in the network is connected at each end to a leg of a respective Y-shaped fitting such that the pipes each form one side in a hexagonal shaped pipe network formation. Alternate “Y” shaped plumbing fittings are fitted with watering outlets.