A 1/2 fill valve with bottom entry, brass shank and non-delayed action fills a cistern fast and even at pressures as low as 0.1 bar and is suitable for mains and gravity systems. It eliminates the need for an additional check valve, is compatible with virtually all cisterns, is easy to install, is fully recyclable, is BREEAM approved and complies to all standards and regulations of BS 1212-4.