Traditional manufacturing methods, namely machining, forging, casting and welding, typically impose processing limitations in design and lead times. This is especially true for bespoke or low-volume components.

Additive manufacturing has proven to be transformative in low volume manufacturing. This has also been a boon to processing equipment, which is benefitting from 3D printing's customizability, design flexibility, rapid trial cycles and performance optimization.

How 3D printing makes a difference for process components

The innate manufacturing limitations of subtractive manufacturing can create inefficiencies in a number of ways.

Custom valve and pipeline bodies and inserts with complex internal channels can optimize flow paths, but integrating sealing features to match that complexity is impractical using extractive methods. However, these can be 3D printed to enhance performance and reduce parts count. This was recently demonstrated in a desalination system, which reduced energy consumption by 10%.

Heat exchanger components often use intricate lattice or cellular structures to increase surface area, improve heat transfer and reduce weight. Such features are highly effective but are highly expensive to machine. 3D printing enables designs with enhanced surface area and optimized fluid characteristics, unattainable by other methods.

Static mixers with complex internal geometries can improve mixing efficiency in many applications, and can easily be tailored for individual solution viscosities, corrosiveness or agitation needs. In fact, while manufacturing the electrolyte for some battery technologies, 3D printed static mixers are fabricated with a specific conductivity to improve charge transfer.

The extreme variety of raw materials that need to be processed mean that common engineering solutions to manufacturing them are few and far between. While those are very specific examples of meaningful contributions to processing, 3D printing also contributes in many of its more common ways. Sensor and instrument housings can be highly adapted for integration with piping or process vessels. The ability to integrate housings into structural components can enhance strength and reduce costs.

Repair and replacement parts that are obsolete or unavailable can be reverse-engineered by 3D scanning, or reproduced from existing data files and printed onsite or near-site. This can be invaluable in remote use cases, such as orbital applications.

3D printing landscape: Machines and materials

Additive manufacturing encompasses a huge range of materials and processing methods. Each material option offers opportunities in resolution, mechanical properties, surface finish and cost.

3D printed materials generally fall into one of four classes: polymers, photopolymers, metals and ceramics/hybrids. The material must safely and effectively interact with the raw material to be processed, yet it also must meet the acceptable precision and quality to be compatible with the processing equipment. This means that not every highly-custom processing component can be 3D printed and manufacturers typically must accept that some post-processing on 3D printed parts might be required.

Fused deposition modeling (FDM) is the most accessible type of 3D printing. It is typically used for polymer components or prototypes, but can deliver metal parts through polymer-suspended metal power source materials that require extensive and complex post processing (debinding and sintering). While the polymer parts can be of relatively high accuracy with high-performing equipment, the desktop end delivers relatively low functional accuracy and high anisotropy. The parts are generally of modest strength, just 10% to 20% that of molded material, but the equipment accessibility and low cost of parts makes this an attractive option where quality achieves "good-enough" status.

Metal parts made by FDM are essentially experimental or visual only. The precision resulting from sinter-induced shrinkage is relatively poor and non-uniform, depending on section orientation and thickness. Density or porosity can also be a significant issue.

Selective laser melting (SLM) and direct metal laser sintering (DMLS) uses the melting and fusing of metal powders, spread in thin layers, using a high-powered laser. This builds dense, high-strength parts suitable for process equipment. The resolution of the higher performance SLM or DMLS machines can make high functioning and precise components, though post work is typically required for high tolerance workpieces. Cosmetic surfaces range from sandy to smoothed to grainy in texture, with good overall flatness, but the average roughness (Ra) values can vary between 5 and 50µm.

Electron beam melting (EBM) is similar to SLM but uses an electron beam as opposed to a laser. It is considered most effective for titanium alloys, delivering high density, good mechanical properties and similar surface quality to the high end of the SLM range.

Post-print steps will vary considerably according to process constraints, material types and precision required in final parts. This may include heat treatment (e.g., stress relief, annealing), machining critical surfaces, surface finishing (e.g., polishing, coating), wash or abrasion of support structures. Parts that are first of type may require non-destructive testing (NDT), such as CT scanning or ultrasonic inspection, to verify integrity, and to validate methods prior to roll out.

Freedom, advances and challenges

Distributed manufacturing hubs or onsite 3D printing units enable just-in-time production and localized spare part fabrication, minimizing inventory and downtime. This flexibility can be highly beneficial in a number of applications. For example, chemical processing facilities can be located in remote areas, with little worry for spare part procurement, if they can print their own. This same thought process is helpful for military, spacecraft, oil rig and other far-flung applications that will have processing needs.

3D printing opens doors for advanced materials and composites with enhanced corrosion resistance, thermal properties or mechanical strength. For example, Inconel printed heat exchangers withstand harsh chemical environments while maintaining excellent thermal conductivity. The printing of high entropy alloys can allow material options that simply have no other practical manufacturing method.

Despite clear and well documented benefits, additive manufacture also faces challenges. Material certification and standards compliance can be essentially impossible, in some cases. New type-compliance requires extensive testing and certification, especially for safety-critical equipment.

There remain surface finish and tolerance concerns, which can vary considerably between process types and materials. Some build methodologies result in rough surfaces or greater dimensional deviations. Post-processing might be unfeasible for some operators, or impossible for those that are truly decentralized.

Scale and size limitations can often make larger parts impractical or complex to execute. Metal 3D printers generally have tight build volume constraints, resulting in the need for modular design or hybrid manufacturing. This negates some of the intrinsic value of AM.

Finally, the cost for additive manufacture of even moderate-volume production is often prohibitive. For larger volumes, traditional methods are certainly more economical.

However, there is ample opportunity for AM technologies to become better intertwined with automation. Software and AI advances can help 3D prints use lessen material and time between jobs. Additionally, the 3D models for prints are already on-hand, lending themselves to digital twins and simulation.

Summary

3D printing is just beginning to revolutionize the fabrication of process equipment components by enabling previously impossible design complexity, customization/tailoring and rapid iteration. This empowers plant operators to innovate faster, reduce costs for specialized parts and respond agilely to evolving operational needs. While challenges certainly exist, successful industrial deployments show it to be a critical tool accelerating innovation in process equipment.

This is becoming essential in the race toward improved efficiency, sustainability and performance.