A close-coupled WC suite is an assembly of a ceramic pan and a cistern joined directly by a bolted, gasket-sealed interface, in which every penetration through the ceramic is sealed by a compressible washer placed on the wet (internal) face and clamped by a nut on the dry face — the sealing rule being that the gasket must bear against the pressurised side so hydrostatic pressure assists rather than defeats the seal. The cistern's fill and discharge functions are governed by two interacting level-referenced devices: a float-operated inlet valve that closes the supply at a set water level, and a siphon/flush valve that discharges the stored volume, with the correctness condition that the inlet shutoff level lies below the overflow datum, since otherwise the vessel enters a steady-state overflow rather than reaching equilibrium. This belongs to sanitary appliance installation within plumbing and building services, and demonstrates the discipline's general pattern of combining gravity-driven hydraulics, elastomeric static sealing, and mechanical fixing into brittle substrates and building fabric.
A close-coupled WC suite is an assembly of a ceramic pan and a cistern joined directly by a bolted, gasket-sealed interface, in which every penetration through the ceramic is sealed by a compressible…