Page 24 - 3D Metal Printing Fall 2018

3D FEATURE
Valve Industry
Transforms Using Metal AM
This case study illustrates how metal additive manufacturing overcomes traditional manufacturing challenges.
The emergence of severe service valves, smart monitoring systems and highly engineered control products are advancing the traditionally conservative valve industry, with metal additive manufacturing (AM) playing a greater role in new-product development.
Case in point: Bray International, a Houston, TX-based pro- ducer of valves, actuators and accessories, which recently part- nered with Renishaw plc,
well-versed in metrology and
while offering, reduced size and weight, as well as and ball-valve features, such as higher flow capacity.
Currently manufactured via wire EDM (electric discharge machining), these balls are highly customizable, but also have limitations. Bray identified the potential to further increase the flow capacity of this product through AM, and to decrease the cavitation potential at the same time. To achieve this, two 3D-
a manufacturer of metal 3D printers with U.S. operations in West Dundee, IL, to explore possible solutions that metal AM may offer valve manufacturers.
Design Concepts
Brainstorming exercises for this project produced a plethora of ideas ranging from the simple to the com- plex. Eventually, Bray settled on a modified version of a V- port ball valve (Fig. 1). V-port control-valve technology offers exceptional character- ized control, increased linear response and fast response times. These precision-cut balls match the control per- formance of globe valves
Fig. 1—A V-port ball valve provides high flow capacity.
printed balls eliminate abrupt interruptions in the flow path, a consequence of traditional manufacturing methods, thus promoting laminar flow through the valve (Fig. 2). The smooth ball creates, between its full-port- opening side and the v-port side, a smooth transition, a feature not possible through standard CNC machining, while the honeycomb ball straightens flow through sev- eral internal pathways.
Designing for AM
The design process for AM parts contradicts that for tra- ditionally machined compo- nents. When not limited by traditional manufacturing methods (e.g. mill, lathe, CNC), one can think about a
22 | 3D METAL PRINTING • FALL 2018
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