The consistent supply of high-class components to customers in the petrochemical and power-generating industries requires the appropriate mixture of expert engineering skills and machining technology; Sheffield-based X-Cel Superturn has both.
With 100 employees, of whom 35 are shop-floor-based at the company’s Atlas Way facility, this precision machining firm has consistently invested in both its workforce and machining capability to maintain an enviable reputation among its ‘blue-chip’ client base.
The latest investments include a Hankook Protec 9NC flat-bed lathe (complementing existing Protec 9Ns at the site) and a Hankook VTC140/E vertical turning and boring centre — both supplied by Sheffield-based TW Ward CNC Machinery Ltd
(www.wardcnc.com), which is the exclusive UK distributor for the Korean machine tool manufacturer.
The rigidity — and therefore the accuracy and reliability — of the Protec 9NC is derived from its double-walled and ribbed one-piece meehanite cast-iron bed, which features hardened and ground precision slideways.
With a bed length of 5m and a maximum turning length capacity of 3.8m (options for up to 8m are available), the Protec 9NC has been installed to machine predominantly steel and exotic materials for down-hole tools used by customers in the oil industry. These tools, which can be up to 4m long and weigh up to three tonnes, are produced in batches of one to 10.
Machine rigidity
With such large workpieces, machine rigidity is critical to the success of the often extended machining cycles, which usually embrace both turning and boring; the latter uses a long boring bar (up to 1.5m) that is held in the eight-station indexing turret, and a steady rest helps to ensure accuracy.
Other characteristics of the machine that appealed to X-Cel Superturn are the 30/37kW main-spindle motor, the 800mm (254mm bore) chuck, swing diameters over the bed and cross-slide/carriage of 950mm and 630mm respectively, and a maximum turning diameter of 950mm. The machine features a Fanuc 21i-T CNC system, which offers semi-CNC manual guidance and a teach facility.
“We had no doubt about the machine’s build pedigree and performance capabilities,” says managing director Andrew Taylor, “since we have had another two similar models — Protec 9Ns, also supplied by Ward CNC — in use for the past six years.”
X-Cel Superturn also has a new machining facility at the Advanced Manufacturing Park in Sheffield. It was opened recently in response to a £6 million three-year contract to supply precision gaskets and sealing rings to a manufacturer of sub-sea ‘trees’ that are used to ‘top’ underwater well heads and control the flow of oil/gas.
The company was born out of Sheffield Superturn (established by Mr Taylor in 1983 as a sub-contract machinist serving the food, automotive, steel and petrochemical sectors) and X-Cel (GB), which was founded in 1995 to supply metallic and non-metallic seals to the petrochemical and refinery sector. The two companies came together officially in 2007, although they had been collaborating for the previous nine years.
Comprehensive capability
Mr Taylor says: “Our policy has always been to invest to succeed, and this certainly applies to our machining capacity. At our Atlas Way site, which is served by 10- and 25-tonne overhead cranes, this includes an array of deep-hole borers, CNC lathes, mill-turn machines, machining centres with up to five axes, and honing equipment.”
This machining capability is complemented by in-house brazing, shot-blasting, component cleaning and component marking; the company has also established strong relationships with steel stockholders, as well as companies that undertake heat treatment, carbide spraying, hard-facing and grinding. Together, they allow X-Cel Superturn to satisfy a wide range of requirements.
The company’s most recent Ward CNC-supplied machine was a Hankook VTC140/E vertical turning and boring centre, which is currently being used to machine a variety of sub-sea oil seals in a single set-up on its 1,400mm-diameter table.
This machine features C-axis indexing at 0.001deg, a programmable feed rate between 0 and 1,200deg/min, an 18.5kW 3,000rev/min milling spindle, a maximum turning diameter of 1,600mm and a maximum turning height of 1,400mm. It has 24 tool stations (12 each for turning and milling), and the cross-rail has 700mm of vertical travel.
The machine’s ability to turn, drill and tap the seals in one hit (the seals can measure up to 3m in diameter and can weigh 1.5 tonnes) has superseded the traditional process of flat-bed turning a component before transferring it to another machine for drilling and tapping.