We had been working with our customer for some time already, when we received an inquiry for shafts for triple offset valves – shaft is the part that steer the valve disc, opening and closing it and thus regulates the flow of medium in the installation. Shafts are relatively slender (high l/fi ratio) and made of exotic materials – Nitronic, double age hardened 17-4 PH and Monel K500 steels. The problem was to seek for a supplier for the material – as it was found, only few European suppliers can deliver these grades. But the biggest issue was an optimal chose of tools and machining parameters to obtain strict tolerances. Experience in stainless steel didn’t help, as these grades require very much different approach – materials are hard, chip control is poor and tools wear is very rapid. We did overcome all these issues and right now our supplier produces shafts to British customer, who obtained the price reduction. Supplier gained a huge experience, which pays off and leads to opening of new markets. As the sales manager of that company said: “we could get a PhD on these shafts”.

Another example from Valve industry. This time German manufacturer was seeking for a new supplier for butterfly valve bodies – rolled metalplate with welded upper and lower stem housing and XXL boring that requires co-axial positioning of stem housings. The critical issue was to have a proper set of technologies available in one plant, so the supplier could offer good price. Fabrication starts with rolling cut-to-size plates, after which longitudinal welding has to be done to create a cylinder. Next, stem housings need to be welded. Because valve production requires PED directive, welders need to have proper certificates, and seams have to be inspected acc. to UT or PT tests. The problem is to make a proper machining of a main bore and internal diameters of stem housings so they are coaxial – without this condition the disc of the valve will not fit closely to the seats, and the valve in the closed position will be leaking. Metal forming, welding, weld inspection, machining – all processes in one place and satisfied customer, who keeps on working with the Supplier indicated by Promach.

Complex technological processes often occur at the production of construction machinery – one of the them sent us an inquiry for steel construction, welded according to the 3834-2 standard and milled on a gantry-type machine. The biggest challenge was to obtain required tolerances on a big length – the dimensions were changing because of vibration during transport and temperature difference – even though at supplier’s site quality control did not find any discordances , the Customer found it wrong. For this reason we machined it leaving a slight allowance, then left it for a few days in order to eliminate stresses, and then made final machining. With this method we managed to keep repeatability of dimensions without need of using heat treatment or vibratory stress relief. Since the implementation of a new product cooperation has been developing, and customer introduces new products with supplier indicated by Promach.

This time the goal was clear – simple turned and milled parts, low volumes and repeatability, big assortment type and the task: price reduction and maintaining short lead times. We analysed the requisition list and we found, that it is possible to group – to some extend – parts according to the type and dimensions of raw material (round and rectangular bars) and thus enable to stock the proper level of raw material, but also to prepare tooling for shortening set up times to offer a good price. We divided the requisition between two suppliers – as one of them had machines only for turning and the other one – for milling. Suppliers work mainly on conventional machines – and probably because of that they were able to offer good price – customer gained 18% discount/year keeping lead time and quality level, and suppliers, thanks to proper production organization were able to generate satisfying profit. As it was proved, not only CNC machines are the only alternative – sometimes it is better to work on conventional machinery.

Polish customer, a manufacturer of medical devices, used to buy disposable cutting tools for the surgery equipment. This tool is a stainless steel pipe with the wall thickness of only 0,3mm, ended with reduced diameter carried out by pressing processes (bottling) and sharpened by grinding. The pipe must be electropolished as well. First problem was a supply of the material – thanks to Promach actions it was possible to find a supplier in Europe, without need of importing the raw material from China. The basic technological issue was to make a bottling on such a thin pipe, and at the same time – preventing from marks from the tool chuck and other plastic deformation. Even though the production was moved from China to Poland, we managed to decrease the price of the part, which ended up with few dozens of thousands of PLN savings per year. Quality was also improved, and the lead time was reduced radically – from a few months up to a few weeks.