A pressure-regulating valve is not the kind of hardware that normally gets a press cycle. But this one is made of copper-nickel, it came off a laser powder bed fusion machine, and it has been cleared to go aboard a United States Navy submarine. VoxelMatters reported on July 18, 2026 that VACCO Industries has manufactured and delivered the valve for the Navy's submarine fleet sustainment program, with the valve body printed by Penn United Technologies and the finished assembly tested and handed over by VACCO.
For anyone who has spent an afternoon fighting a printer over a material it does not want to run, the interesting word there is copper. Cu-Ni is one of the alloys the additive world has largely stepped around, and qualifying it for a pressure component on a submarine is a different order of problem entirely.
Why copper-nickel is the hard case
Laser powder bed fusion melts a track through a thin layer of metal powder. That assumes two things: the powder absorbs a usable fraction of the energy aimed at it, and the heat stays put long enough to form a stable melt pool. Copper alloys undermine both. Copper is highly reflective, so much of the incident laser energy bounces rather than couples into the powder. What does get absorbed is hauled away fast, because copper is an excellent thermal conductor. The melt pool wants to collapse before it has finished its job.
The consequence is a narrow, unforgiving process window. Push the power to overcome reflectivity and you risk keyholing, spatter and the porosity that follows. Back off and you get lack-of-fusion defects. Neither outcome is acceptable in a part whose whole function is to hold pressure inside a hull that goes deep. That physics is why copper alloys have stayed on the margins of production metal additive manufacturing, and it is why a qualified, pressure-bearing Cu-Ni component reads as a milestone rather than a routine job number.
What it replaces matters as much as what it is
The incumbent process for a Cu-Ni valve body is sand casting, and sand casting of copper-nickel is not a happy process. A casting with internal porosity, inclusions or dimensional drift is scrap, and scrap in a shipbuilding supply chain is a slot in a foundry queue that has to be run again while the fleet waits. The published yield comparison comes not from the VACCO delivery but from a parallel Navy program, discussed below, where printed valve bodies are reported to deliver drastically higher first-time yields than sand-cast Cu-Ni; VoxelMatters gives no yield figures for the VACCO valve itself. The argument holds either way: additive is not winning here because it is exotic, but because the thing it replaces has a bad hit rate.
The funding channel is worth understanding. The work was backed by Submarine Industrial Base funding, routed through the Maritime Sustainment Technology and Innovation Consortium — an Other Transaction Authority program the Navy uses to push advanced manufacturing methods into the fleet without the weight of conventional procurement. Naval Sea Systems Command is the partner organization. After Penn United printed the body, the valve passed non-destructive and production-level testing and was cleared for installation aboard a submarine. VACCO said the outcome "was made possible by the Navy's AM Material Maturity efforts," indicated it plans to use Navy additive material specifications in future production, and described the program as marking progress in "speeding the delivery of components to the fleet while strengthening the Navy's supply chain."
It is not a one-off
The detail that turns this from an interesting demo into a trend is that a second, entirely separate supply chain has arrived at the same answer. Engineering.com reports that Fairbanks Morse Defense is prime on a parallel program, with its subsidiary Hunt Valve — which holds the MSTIC contract — assembling the copper-nickel valve assemblies and Lincoln Electric producing the printed valve bodies. The assemblies weigh roughly 70 pounds each, and as with the VACCO valve only the body is printed; the remaining components are made by traditional methods.
The figures attached to the FMD program belong to that program specifically rather than to VACCO and Penn United. Production time is cut to roughly one-third of what sand casting requires. First-time yields are described as drastically higher than traditional sand-cast Cu-Ni. The approach is expected to increase submarine component production speed by as much as 75 percent. Andrew Pfister, FMD's vice president of aftermarket and product development, called the use of additive manufacturing with copper-nickel for large valve production "a real step forward for our industry," adding: "Not only does it create a superior product in terms of quality, but the process can significantly reduce lead-in times." He tied the work directly to strategic supply: "By scaling additive manufacturing, we can reduce shipping from other parts of the world and increase the speed of production at home – which positively impacts the Navy's overall strategic goal to deliver a 300+ fleet." The assemblies are cleared for deployment on any US Navy submarine.
Two independent teams, two sets of machines, one funding vehicle, and the same conclusion: print the body, machine and assemble the rest conventionally.
What It Means for Makers
Nobody reading this is about to print a submarine valve. The useful takeaways are structural.
First, the hybrid pattern. Neither program prints the whole valve. Both print the geometrically awkward, hard-to-cast body and build everything else by conventional means. That is the instinct a good hobbyist applies when they print a bracket and bolt it to extruded aluminum rather than printing the entire frame. Additive earns its place where the alternative process is worst, not everywhere.
Second, difficult materials get solved when someone has an expensive enough problem. Copper alloys have sat on the "technically possible, practically annoying" list in metal AM for years. What moved Cu-Ni forward was a customer with a fleet to sustain and a casting route it wanted off the critical path. Process knowledge developed under that pressure tends to diffuse outward — into machine parameter libraries, powder specifications and eventually the tooling everyone else uses.
Third, qualification is the actual product. The printing is the easy half. What VACCO delivered alongside the valve is a documented path through non-destructive and production-level testing to a cleared installation. In any regulated context — aerospace, medical, marine — the paperwork trail is the barrier, not the machine, and it is the part that gets faster once someone has walked it first.
One caveat on sourcing: no standalone press release from VACCO or Penn United could be located. VoxelMatters stands as the source of record for the VACCO delivery, Engineering.com for the Fairbanks Morse program.
