When each raw material casting or forging can cost up to £90,000, it is clear that care, skill and confidence in its machining and complete production process are critical to Koso Kent Introl (KKI) for the specialist valve bodies it manufactures for the sub-sea, oil and gas and petrochemical sectors.
Key to the company’s ever-growing confidence in its production capabilities is the installation of a Dörries Scharmann Technologie GmbH (part of Starrag Group)-supplied Scharmann ECOFORCE 1 HT2 horizontal machining centre.
The machine is primarily engaged in bespoke component machining (more than a one-off would be regarded by KKI as volume or series production) where cycle times exceeding 24 hours are usual - continuous cycle running over three manned shifts when setter-operators hand over to each other.
Lynn Mowbray, Operations Director at the Brighouse (West Yorkshire) company, comments: “We were rapidly running out of machining capacity for our ‘made-to-order’ specialist capability but, due to the type of production and the distinct pressures involved in achieving a ‘right first time’ philosophy in components of difficult-to-machine materials, as well as the large machining capacity involved, very few machine tools meet our strict production requirements.”
That said, she adds, machine selection was made easier by the fact that KKI enjoys an established track record (more than 25 years) with Dörries Scharmann, with three highly successful machine installations, including a now ageing Dörries vertical turning lathe that is still very capable of roughing out 18 inch (457 mm) housings.
Scharmann ECOFORCE enhances production skills for bespoke valve machining
To meet the bespoke demands of its valve industry customers, KKI is entrenched in providing design, development, application and special testing support from its 10,095 m2 three-building facility. Also part of the bespoke offering to customers is an after-care service that is an intrinsic part of valve maintenance, where KKI can be called upon to provide emergency support.
The plant’s output covers severe service control and butterfly valves, surface and subsea choke valves, control valves and subsea control valves. The site produces an average of 20 valves each week with capacities ranging from one inch (25 mm) to 20 inch (508 mm) in highly demanding materials that include titanium, Inconel, Super Duplex, Duplex and stainless steels.
The severe service valves are designed to accommodate multiple field applications including high-pressure and high-temperature tasks. They also have to cater for the effects of cavitation, high velocity, vibration, flashing, noise and energy dissipation as well as solid contamination in fluids.
KKI has a strict ‘made-in-house’ philosophy and as the only European wholly-owned subsidiary of Nihon Koso - the Japanese-based global leader in controls and process automation systems - the £34 million turnover UK operation must maintain an investment-led programme to ensure application, delivery and quality are adhered to says Mrs Mowbray: “Any delay to a project or having a faulty valve sub-sea could have serious repercussions, so we continuously demonstrate we have the resource and capability.”
Major areas in the production cycle involve large face and flange turning, and the production of multiple bores in adjacent or angled faces. These can be up to 700 mm diameter and 600 mm deep and are produced using special boring bars to obtain +/- 0.02 as normal tolerances or, in some special cases, a total tolerance of 0.01 mm. Drawing requirements can even include offset and semi-circular operations. Most components also require pitch circle drilling.
Installed on massive prepared foundations, the high-specification ECOFORCE features a 50 kW, 4,000 revs/min spindle drive with 2,200 Nm of torque available. However, also included in the specification is a facing head with a maximum turning diameter of 1,250 mm. This head has a speed of 300 revs/min and a massive 6,000 Nm of torque available. The W axis is 375 mm and the U axis is +/- 100 mm.
