Profile: William Cook Leeds Ltd. sophisticated components, assemblies and systems for a huge range of applications. Our diffuser casting is in super duplex stainless steel and weighs 3 tonnes. It forms part of a vertical pump for a de-salination plant. The chain lifter weighs 2 tonnes and is supplied finish machined ready for use on an oil rig. The innovative combination coupler, which allows rail vehicles with different types of coupler to be coupled together, was designed and manufactured from cast & machined components. The transverse bolster comprises five steel castings, all individually machined before being welded together into the finished assembly. That assembly is then finish machined, pressure tested and painted.