Flexible manufacturing: getting it right first time

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  • Flexible manufacturing: getting it right first time

    Every pump produced to order, every pump tested before shipment: these are familiar claims from a manufacturer of large engineered pumps. However, when the Editor recently v&&ted Calpeda s factory in northeastern Italy to view its pro duction facility and investigate the companys unusual approach to quality control, be was intrigued to discover the same claims being made by a major player in the volume pump market.

    Flexibility to order

    Calpedas production philosophy is founded on two main principles: having the flexibility to offer the customer what they want, when they

    want it, and then making sure it will work when it is delivered and installed. This is an interesting approach since it throws up a number of contradictions. At the beginning of the produc- tion process, each operator handles hundreds of components an hour in automated batch ma- chining processes; at the end of the production process, one man tests each pump individually. This balance between volume production and quality is a welcome approach in a world increasingly led by the marketplace.

    However, even at the first stage of the process, the shaft welding operation, the shaft is more than just a component. It already represents a pump that has been ordered. A unique barcode identifies it with the order and will stay with it as it progresses through the production process towards assembly and testing.

    The reasoning behind testing every pump, even though the capital cost of the pump may not be high, stems from Calpedas commitment to maintaining a reputation for quality. A good proportion of the companys products are sold to original equipment manufacturers, and those OEMs rely on the pumps working first time.

    Calpeda worked with local machine tool makers to develop a unique friction welding system for pump shafts (above).

    Motors are manufactured on site to European standards (left).

    glil WORLD PUMPS JUNE 1996 Copyright 0 1996, Elsevier Science Ltd All rights reserved. 0262 1762/96/$15.00


    The manufacturing process

    Calpedas home is in Montorso Vicentino, just outside Vicenza in Northern Italy. This is an area famous for steel making and machinery indus- tries. The specialist skills of these local machine tool manufacturers have been heavily exploited by Calpeda. They have worked with local suppliers to develop unique machine tools, customized to the companys own requirements. The close cooperation is evident at every stage in the manufacturing process, starting at the very beginning - with the pumpshaft. Here 300 series stainless steel is friction welded to mild steel to produce a composite shaft. The composite shaft combines a wet end that is resistant to corrosion while retaining a motor shaft end with suitable magnetic properties to give high motor eff- ciency. This custom engineered solution provides the optimum component and negates the need for couplings or compromise on wet end corro- sion performance. A sensible piece of engineering and one pioneered in this plant.

    The pump rapidly takes shape as the compo- nents proceed through a series of automated machining stages. These include machining of the shaft, rotor fitting, alignment and rotor machining, grinding and balancing.

    The impellers are machined from castings in another flexible but volume process. We watched as the machining centre handled the switch to a different impeller without the need for resetting. The impellers are then balanced automatically.

    Casings, housings and lanterns from Calpe- das own foundries are larger and more complex and so more machines are required. Interest- ingly, Calpeda has chosen to machine the housing feet and the outside of flanges, a notable attention to detail in a volume market and one that could make a lot of difference in overcoming pump installation problems.

    The motors are the only components not made for a specific order. Nevertheless, there are some interesting technical developments in the motor manufacturing area as well. The motor windings use a resin-coated wire which is baked and then tested before the insulation is added and the unit is fitted into its casing.

    Assembly and testing

    Eight benches are assigned to assembly of the pumps. At this stage each pump gets individual attention. The process is not auto- mated but is accelerated by the prior attention to quality control and the convenience of modern power tools.

    At the assembly stage each pump receives individual attention (top). Every pump is tested, either by hand (middle) or using the latest computer-based rigs (bottom).

    Once assembled, every pump is tested. In the past this meant a manual test in which every pump is run. The closed valve pressure is checked, a full load current test is made on the motor and the operator makes a visual inspec-


  • The latest product of Calpedas research and development department (above) is the stainless steel GX submersible pump (right).

    tion for leaks etc. Any failure is immediately acted upon.

    Recently, an impressive computer testing regime has been introduced. The computer runs the tests automatically and logs the results. At present, two computer test rigs are being used to test the larger pumps including the NM series end-suction centrifugals and the multi-stage MXV range. The number of pumps tested in this way will be increased, although some ranges will continue to be tested manually in the interests of speed. It is worth noting that even Calpedas small submersible drainage pumps are run after assembly.

    The production process ends with a remark- ably clean robot-painting facility, after which the pumps are packaged, and then shipped. As mentioned before, these pumps are produced to order and stock is not generally held at the factory.

    m Quality control

    Calpeda is a production-driven manufacturer. 238 people are employed at the headquarters, around 190 of whom work on the shop floor. Quality control comes from a company culture of getting things right first time. Individual ma- chine tool operators are responsible for taking continuous samples of components to check quality. This is supported by a central control and management team that ensures component quality to very high levels of accuracy using a high-tech precision dimensioning apparatus. Cutting tool and machine specifications are also checked and calibrated against standard refer- ences by this team.

    Although Calpeda operates to a fully pre- pared IS09000 manual, the company has not sought accreditation, a point I raised with a senior company executive. We operate in line with the quality manuals at every stage of production, research and development but with-

    out the paperwork, he explained. He went on to explain how the Calpeda system of flexibility and bar-coding was essential if the company is to continue to meet its standard of delivering any order, regardless of volume, within three working days. Implementing IS09001 would prevent the company from maintaining that schedule and so a strategic decision was taken to persevere with Calpedas own quality system. IS09001 is not a guarantee of quality, insists Calpeda it only guarantees a system of paperwork and repeat- ability. Our testing and quality system delivers real quality, and allows us to produce up to 1800 units each day with total flexibility.

    Future developments

    Quite separate from the regular product testing programme, Calpeda maintains a busy research and development test centre that is used for product development as well as any certified testing that might be requested by a customer. The flexibility of the production facility allows the company to manufacture a tremendously wide range of products. New product develop- ment is an important activity, and not one that can be rushed.

    Use of pre-fabricated components made of stainless steel or advanced copolymers is in- creasingly important and Calpeda is presently fitting out a 9000 m2 extension to its factory just to handle the assembly of these products. Currently, Calpeda exports 50% of its produc- tion. These pumps are sold through eight directly owned subsidiaries, including a recently opened office in Ireland, and around 40 agents.

    In spite of the growth of its export business, one over-riding impression remains after a visit to Calpeda. This is a fiercely independent company that believes it has found the right approach to manufacturing pumps for its market. And nothing will cause the company to compromise its standards. ??



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