I'm in the process of building a boiler test rig Mike, although it's not quite finished. I generally based my pump on the design published in EIM May/June 2009. I modified it to use what I had available (brass pump body, aliminium block and stainless steel handle & ram ect. It uses O rings in the valves rather than trying to seat a stainless ball effectively. I found it easy to size the pump to suit the materials to hand and apart from my time – it's cost me nothing. Regards, IanT