One-hit savings on oil & gas valves and fluid ends

The productivity benefits that oil and gas companies can gain by using Starrag’s Heckert DBF horizontal machining centers are unquestionable – thanks to the machines’ integral U-axis that carries the Starrag DBF multi- tasking head, the rewards for one-hit, multi-facet, multi-face machining are unrivalled!

“Whether you want a standalone solution or a highly automated one, the DBF series offers the highest throughputs with a superior surface finish and excellent precision.” 

Doug Henderson, Vice President of Sales at Starrag US

The DBF spindle head comprises an integrated work spindle with CNC radial facing slide for the U-axis travel. For turning on a fixed workpiece, the rotating turning tool – which has an axial runout of just five/six microns – can be radially adjusted by + / – 1.38 in. In addition to external, internal and face turning, the head also permits conical and contour turning courtesy of the radial facing slide’s NC axis. Unlike other U-axis tools add on units, the DBF provides 1,200 rpm, 60.35 hp of continuous power, and 1,254 ft / lbf of continuous torque allowing the U-axis to efficiently rough and finish features with a superior degree of accuracy.

For milling and drilling, the work spindle is arranged in the U-axis central position and is capable of delivery 3,500 rpm, 60.35 hp of continuous power, and 66.93 in continuous torque. This allows the machine to perform effectively as a horizontal machining center for roughing and finishing when the U-axis is not required.

77% reduction in cycle times

Utilizing the DBF machines’ single set-up ability to mill, drill and turn fluid ends, gate valves, drill bits and pump housings, for example, users have been able to slash machining times – in one instance, on control valves, from 20 hours to just 4.5 hours, achieving a 77% reduction in cycle times and a 95% reduction in overall processing times. 

In a case, when the machine was complemented by a six-pallet linear storage system and 320-tool ATC storage, a DBF 1000 machining center – ideal for fluid ends due to their weight – runs unmanned and undertakes a non-stop routine of face milling using a 4.92 in diameter cutter at a feed rate of 196.85 ipm, end milling using a 1.97 in diameter tool, solid drilling (2.76 in diameter tool) then turning with an 3.5 in diameter tooling and a 11.81 in diameter external turning tool.


Accuracies of just 5 – 6 microns

The capabilities of the DBF machines’ axes offer unrivalled flexibility in the machining of a multitude of facets – internal and external – on every face of a workpiece (except the clamping face), and with an axial runout accuracy of just 5 – 6 microns, all tolerance and concentricity values are consistently held, whatever the range and complexity of machining applications.

“Compared to other machines that may offer, say, facing head tooling via a toolchanger, the integrated DBF spindle utilises industry-standard tool holders such as HSK 100 and Capto, this allows DBF head users to buy standard tool holders to cover all turning sizes up to 19.69 in versus an additional facing head being required for every 2.76 in of travel.” says Starrag US Vice President of Sales, Doug Henderson.

“The result is that with the integrated U-axis, the tool tip is much closer to the spindle bearings and this leads to much more rigidity at the tool tip and therefore more accurate machining. Additionally, the integrated DBF spindle has the torque and power to maximize the machining process efficiency”

DBF has replaced two roughing and one finishing machines

Doug Henderson adds: “And, of course, the DBF’s all-in-one process obviates the need (and expense) for separate roughing and finishing machines – in one case, a single DBF machine has replaced two 4-axis roughing machines and one 4-axis finishing machine – as well as the extra time and potential inaccuracies of workpiece re-location that accompany separate processes. It’s a perfect example of Starrag’s philosophy of ‘Engineering precisely what you value’. ”Whether stand alone or highly automated the Starrag DBF solutions provide the highest throughputs with superior surface finishes and excellent precision. 

“Industrie 4.0” solutions with Starrag´s IPS

When applied in fully automated systems integrated by linear pallet systems and sophisticated, highly intelligent software routines to create high-performance manufacturing cells that boast maximum automation with minimal operator involvement. These “Industrie 4.0” solutions are ideally supported by Starrag´s IPS (Integrated Production System).

Another example – the production of fluid ends which have average life cycles of 2,000 / 3,000 hours – sees a DBF model machining the ends from solid stainless steel blocks of four tonnes in just 32 hours instead of 50 hours. That’s a cycle time saving of 36%. The secret to the success of the Heckert DBF range of 5-axis machines (6-axis machining – without axis interpolation – when a tilting, NC rotary table is added, resulting in less complicated fixturing) is the integral U-axis that carries the DBF machining head which allows both roughing and finishing on both the U-axis and the ‘standard’ horizontal spindle. Additionally, the machines offer an extended Z-axis travel to permit long-hole drilling as required in fluid ends, for example. 

Combined, the capability of these axes therefore enable fluid ends to be cost-effectively and efficiently processed from roughing through to finishing.