3D Printing A Check Valve In Metal

[SunShine] has been working on 3D printed pumps and similar parts with an aim towards building smaller and more compact hydraulic systems. His latest effort involves printing working hydraulic check valves that can be integrated seamlessly into his designs. 

Unlike many 3D printing enthusiasts, [SunShine] works with metal printers of the laser powder bed type. His expectations for his parts are thus very high, and he aimed to create check valves that could withstand high hydraulic pressures.

After much work, [SunShine] came up with two designs for 3D-printed check valves that would work. However, they both needed internal removal of support structures that couldn’t be achieved without cutting them open. He then figured out that he could use a special process using nitric acid to carefully eat away a very precise amount of metal inside the valves, which would remove the support material without destroying the whole valve itself.

While the valves couldn’t be tested beyond 400 bar due to the available equipment, they did work as intended. As a bonus, they actually sealed better as they were used more, as the sealing surfaces bedded in and deformed to match each other.

The video is then rounded out with a simple plastic check valve design you can print at home. It reminds us of other valves we’ve seen created with 3D printing before. Video after the break.

Thanks to [Zane Atkins] for the tip!

34 thoughts on “3D Printing A Check Valve In Metal

    1. Yes indeed. I think it’s high time for an experiment to be conducted to see how well a robot manages an organisation / company or even small country like Lichtenstein. Any suitable contenders?

    2. As the mechanical butter churn replaced women’s jobs in 1890. Or the way the entire industrial revolution replaced farm and factory hands across the board. And cars replaced horses which removed the jobs of stable-boys.

      The jobs are not removed, they simply change in nature, and those that bemoan the change get left behind.

      1. The jobs do get removed, though. We’ve been doing busy-work for a century because we can’t figure out how to deal with that. “I pat your back and you pat mine, we exchange $20 bills and the GDP goes up $40”. It’s a real problem.

        1. Create $50 Million a day of economic activity in your basement with this one weird trick…

          draw a line on the bench, left side belongs to an entity which is a gold dealer, right side belongs to a consumer. now mount an old furnace or appliance motor with it’s shaft parallel to the line. Make a wheel to put on it, glue gold worth $10, like an old CPU on one side, and a $10 bill on the other. Position it so the consumer starts with $10 and the gold dealer with $10 worth of gold. Now run the motor at 3600 RPM x 60 mins, x 24 hours a day.

          1. You know when bean counters say your job is easy, then proceed to demonstrate to everyone they don’t understand your job at all?

            That’s you, just in reverse. ‘You understand nothing of beans!’

            Not funny, just stupid.

          2. >Not funny, just stupid.

            It’s true though. For example, a large company gets split in two: one half starts selling “services” to the other half, which used to be internal bookkeeping but now counts as GDP in the economy. Privatization, outsourcing, etc. means there’s more money changing hands in public, therefore more money (and more taxes to collect), therefore “productivity” is growing – though not really. It’s all effectively just like described. Money goes around and nothing much happens except people using energy and materials to run around doing it.

      2. The issue is that it only takes about 4-5% of the economy to produce all the food we eat, and another 4-5% to extract all the energy we use. Add a couple percentage points for manufacturing, but most of that has been outsourced and replaced with imports.

        In essence, about 1/5th of the population is doing everything we need to live and thrive – the rest are working very hard merely to redistribute money in order to claim a share of all the goodies. Hence why the services economy and consumerism was invented. If we didn’t waste our resources buying throw-away t-shirts and expensive artisanal coffees, we would all be so much richer – but nobody would have any money to buy it.

        1. I’d argue that at least some of the remaining population are doing work we require to thrive – humans are not robots and do not do well without entertainment or variety.

          That essential production for life to exist is not the entirety of what is needed to thrive – for instance how much shallower and worse would our lives and productive output be if folks didn’t spend their time writing these articles and commenting on them and so sharing knowledge of a wider field than whatever specific thing we work on.

          Or how about I’m enough of a chemist to know what does and doesn’t work to dissolve steel alloys for instance, and maybe I’d be able to remember enough of the extra interactions and have enough ingenuity to then come up with the idea used here to very selectively trim out the required supports, eventually. But now if I ever need such a process its filed away as a possibility already, all I have to do is look up the reaction chains used, and that concept might prove useful in so many other situations.

          Or in short don’t dismiss artisanal coffee as unimportant to the thriving of humans. At least in those societies so broken as to prefer coffee to tea… It brings some small joy to the lives of the consumers, making them better able to function at whatever it is they are supposed to be doing!

          1. Notice that I counted about 10% for the material and energy production side, and another 10% for the other necessary stuff, including banking, entertainment etc. to reach the 1/5th estimate. For example, Hollywood represents about 3.2% of the economy.

            A good third of the economy is just retail and commerce – people selling stuff to other people. Advertising accounts for 19% of the total economic output, and that’s completely ridiculous.


            You have a point in that we need a little bit of luxury to make life interesting, but that argument is completely overshadowed by the pointlessness of the services economy, which doesn’t even produce luxuries – just spam and low quality trivial consumption.

          2. Making hollywood 1/3 of of 10% ‘other necessary stuff’, what about the music industry that also has huge amounts of money changing hands, and these days ultimately I suspect both are dwarfed by all the little minnows creating more niche and artistically free from constraints content paid for via Kickstarter/Patreon type schemes and the ad revenues of Youtube (etc).

            I don’t disagree there is a portion of the population working while not making anything that actually has any merit for the species or society as a whole (though no doubt helps make their boss richer). But I’d not be nearly as quick to call something like 80% of workers pointless as you are suggesting.

            Even advertising and lobbyists much as its easy to hate and pick flaws with them and the system as it stands has some purpose in the demonstrating and spreading the good ideas, while being a form of ‘entertainment’, mental stimulation anyway – its only when they are morally bankrupt snake oil salesman they render their job pointless to society as whole.

          3. Your primary group of useless workers are those required by mis-regulation, not those who ultimately sell something to someone. e.g. The ‘sexual harassment pandas’ of the world that repeat derp once per year in corporate environments, wasting everybody’s time while making unearned bucks.

            Insurance companies and lawyers are as much to blame as government.

        1. Yeah, I was thinking of a segment of a line that an instructor passed around a class once, that illustrated what happens when a line carrying 3000+ psi air fails. Looked like a soap bubble does as it pops, frozen in time and steel.

          1. The most dangerous are the pinhole leaks, the pressure causes the stream to cut its way though things. We used to use a straw broom to check for leaks, when the broom passed through the leak it would cut pieces off the straw broom.

          2. Pinholes are nasty in hydraulics too.

            The fluid gets under your skin and kills everything. It’s possible to not notice the injury at first. Which can kill you dead, otherwise you’ll likely keep the limb, but you won’t like it.

    1. These are test pieces really. If you have to have the valves accessible from the outside you could just as well screw in normal valves. Also it takes quite some work in fixtureing and such to set it up for milling. This method, removing them chemically is very easy to scale.

  1. Over engineering a solution to a problem that doesn’t exist.

    Since a host needs to be connected to this device with a pipefitting perhaps, then why not just 3D print the V feature into the device then machine it to size, and then insert a popet / ball adn spring before putting on the fitting?

    Take a basic standard inline check valve, there is usually an inner thread holding the spring, or inner assembly. Make it the same.

    Sure this guy may have degrees and such but based on his looks, the years of experience are just not there.

    My past experience to make this statement: Senior product engineer for a hydraulic company, worked as engineer for 2 others.

    1. It’s called job creation. The designer is unemployed or underemployed with a masters degree and is trying to impress a blond eyed blue haired HR robot with technical buzzwords.

      1. Why would you design such a device? It would be completely non-serviceable, and in manufacturing a single flaw in one of those print-in-place valves would scrap the entire unit (high manufacturing loss).

          1. Now compare the failure rates and the economic implications on number of features economic to produce per piece.

            To the stories credit, at least they aren’t printing something easily manufactured by conventional methods. You never know what future 3d printing tech is coming.

            That said, check valves are a well trodden area. The extra size and bad metallurgy of this ones spring make it an unlikely useful design. You could lose that spring and have room for threads and access.

    2. The point they clearly express is to put these structures into inaccessible areas of parts. To create a giant array of other functional parts, thus creating a smaller volume than the separate parts would be print in place complete monolithic system.

      Personally for 99.9% of uses that seems like a stupid idea. Any parts that may wear, fatigue or fill with crude that needs cleaning out over time being inaccessible and not serviceable means throwing out the whole damn thing for one small failure. Some degree of combining often makes sense, and there are niches for such systems compact all in one systems no doubt, but still…

  2. You do realize that the hydraulics industry is avidly looking into 3D metal printing for material and size reduction?
    As much as I personally hate the phenomenon, integrated units that can be thrown away and replaced in no time, is king. NOBODY in the industry cares about being able to replace an internally mounted 1/4″ ball spring valve in a manifold, if the manifold can be replaced in a heart beat and production can continue.

    Size/dimensions of hydraulic systems are also very much a problem that is feverishly being addressed..
    Manifolds are usually made from ‘bar stock’ aluminum or steel, which is drilled and milled to accept screw in, poppet type valves etc. This wastes a lot of material and tends to be bulky.

    Stacking NG valves is great, but if you could make a check valve sandwich plate like the one seen here, then you wouldn’t have to make one from bar stock, mill and drill it, manually plug support channels and finally install the actual check valve before it makes it to the end user.

    Rexroth have made some basic manifolds and Aidro (https://amfg.ai/2020/04/16/application-spotlight-how-3d-printing-enables-better-performing-hydraulic-components/) have made some good looking ones too.
    Even the company I work for, have successfully designed and tested some inline filter bowl manifolds (we outsourced the printing, since we’re new to this ) that will soon enter production.

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