Stainless Needle Bearings

[Adam Uhl]

I am designing a valve for use in liquid oxygen. I want to use needle bearings but they need to be stainless steel for fluid compatibility reasons. My search for off the shelf solutions has come up blank and custom bearing quotes have been prohibitively expensive.

Does anyone know who makes stainless radial needle bearings? I need approximately 5/8 to 3/4" ID.

[Marky]

Hi Adam and welcome to the forum....please give us more info maybe we can help find one or even an alternative.

Speed/RPM's
Fluid

Thanks

[PinkertonD]

Hi Adam and welcome to the forum.

Needle roller bearings are usually used in high-load and high speed applications. What makes you so sure you need to use needle rollers for a valve? For liquid Oxygen, I would be looking for something like a bush-bearing. If it has to go from high ambient to LOX operational temperatures, and clearances are critical, then look for something with minimal Thermal Coefficient of expansion.

Dave
Generally, I will not give you the answer to your question, but I *will* guide you into discovering how to solve this yourself.

[PinkertonD]

Fluid

Oh dear, dare I say it?? LOL Marky, slow down, LOX

At least you said "Fluid" and not "Liquid."

Dave
Generally, I will not give you the answer to your question, but I *will* guide you into discovering how to solve this yourself.

[Adam Uhl]

Its a quarter turn valve that actuates in about 250 ms. Lets call it 60 rpm. The service life will only be a few thousand cycles but the loads will be high. I'm looking for needle vs ball because I am packaging constrained and the ball bearings that fit will not carry the load.

My goal is to keep the friction as low as possible. This allows a smaller actuator and higher reliability.

[PinkertonD]

Its a quarter turn valve that actuates in about 250 ms. Lets call it 60 rpm.

Size matters. A quarter turn at 60rpm on a 1" lever is nothing, a quarter turn on a two foot lever is something. Moot though, just thought I'd grumble a bit about never getting enough information.

I think you are worrying over nothing. The "friction" would be negligible in a quarter turn, but anyway, your call on that.

Why stainless? What about steel needles and O-ring seals top and bottom, sploosh of grease. The O-ring will be no bigger in cross-section than the bearings and easy to incorporate.

Dave
Generally, I will not give you the answer to your question, but I *will* guide you into discovering how to solve this yourself.

[devitg]

never mix oxigen with grease or oil

[PinkertonD]

Dev, in the interests of accuracy, "never mix Hydrocarbon-based grease with oxygen equipment." However there are a lot of greases out there that are perfectly safe with Oxygen. To wit, Silicon grease, just to name one.

My thinking was that anyone building stuff to handle LOX would already know about those dangers, but it was good you raised the point for clarification.

Dave
Generally, I will not give you the answer to your question, but I *will* guide you into discovering how to solve this yourself.