Hygrade Products Limited 667B Great South Road , Penrose , Auckland 1061 New Zealand About Solutions products Companies Hygrade Products Limited Products 8 products found Products Earthenware Vitrified clay pipes, fittings and accessories for domestic, urban and industrial sewerage systems. Pits & Grates Small PVC catchment pits, with grates, for domestic water reticulation. Flexible Couplers Rubber couplers with stainless steel clamps and shear bands for repairs and/or jointing of all drainage pipes. Cast Iron Nation wide coverage of all streetware requirements. Manhole covers, stormwater grates, surface boxes, including “S Mark” products. Ductile Iron The premier range of gas and air tight access covers in all load strengths. Valves Sluice Valves - resilient seated gate valves with smooth straight-through bore of ductile iron. Service Valves - small bore valves with various jointing combinations. Ductile Iron Pipe Fittings Australian standard pipe fittings with spigot, socket, and flanged ends. Couplers & Gibaults Universal pipe couplers and gibaults, designed to accommodate plain-ended pipes with different outside diameters, thus reducing stocks.