# Source for nitrile balls



## Joel779 (Jan 2, 2008)

I would like to replace my stainless 3mm check balls in my Aster engines with nitrile balls. I have looked online but the only ones I can seem to find are in inch dimensions, and there is a limited selection of sizes. Can someone suggest a source for these and what size would be usable as a replacement if I need to go imperial?

3mm = .118 inches


3/32 = .094
7/64 = .109
1/8 = .125 

1/8 seems that it would be too large to use, I don't think the other sizes are available. Any suggestions?

Thanks much.


Joel


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## David Leech (Dec 9, 2008)

Joel, 
That's interesting, as I am busy replacing all the nitrile (rubber?) balls in my Accucraft, with stainless! 
Especially those in the safety valves. 
All the best, 
David Leech, Delta, Canada


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## Joel779 (Jan 2, 2008)

Cool, wanna trade?


seriously, I would be interested in the pros and cons of nitrile balls. I was reading that under high pressure they can deform enough to stick quite badly. I have a check valve seat on my Pannier that needs to be tight. I put new stainless in it, but it seems to drizzle quite a bit from the filler line. Since this is an open line and not a tender pump I would like a good tight s seal. 

I'm not sure that the pressures we run ( 40-60lb/sq ) would be high enough to deform the balls, maybe even replacing them from time to time. The idea of a better seal against a check valve seat was the original reason. I'm not looking to replace the safeties, and probably not even the pump balls.


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## chooch (Jan 2, 2008)

Joel,
I've replaced my check valve balls with Nitrile balls purchased at the time from Sluphur Springs Steam Models. That was many years ago. They sold three sizes (1/8, 5/32, 3/16) and I bought a selection of each for testing. I came to the conclusion that the 5/32 worked best on my Hudson and Mikado. They have been installed and working fine for over 5 years now. For the price, it's worth buying some 1/8 and 5/32 and give both a try. If I remember correctly, the 1/8 did stick from time to time. Most likely deformed a little too much and seated itself too deep. Also, a little white vinegar pushed through the valve with a syringe usually cleans the ball and seat in most cases where you are having problems (both stainless and nitrile).

Hope this information helps.


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## Captain Dan (Feb 7, 2008)

Replace the 3mm with 1/8 nitrile balls

http://www.pollymodelengineering.co.uk/index.asp

Go to page 58 in their catalog.


http://shop.maidstone-engineering.co.uk/

Look under fittings. (they also sell some supplies on ebay)


I don't know of US suppliers. Might try McMaster-Carr.

Dan


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## rbednarik (Jan 2, 2008)

Small Parts in Florida carries nitrile rubber balls in SAE sizes, for the cost of a small pack from the UK, you can have enough to last half a dozen engines or more!


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## TrotFox (Feb 15, 2008)

Posted By Captain Dan on 28 Jul 2010 07:40 PM 
Replace the 3mm with 1/8 nitrile balls



I don't know of US suppliers. Might try McMaster-Carr.

Dan


http://www.mcmaster.com/#nitrile-rubber-balls/=878u90

Just to save some time...

I buy from McMaster Carr all the time at work. They have one of the most useful assortments of stuff to be found anywhere.


Trot, the stuff-lovin', fox...


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## David Leech (Dec 9, 2008)

Trot, 
The balls that they sell seem a little on the large size! 
3/16" and up? 
All the best, 
David Leech, Delta, Canada


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## hcampbell (Jan 2, 2008)

Nitrile balls seem to have an upper temperature limit of around 210° F. Isn't that way too low for a boiler check valve? 
PTFE balls are rated around 500° F. 

Harvey C.


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## TrotFox (Feb 15, 2008)

David, 

Good point, I missed that! They do carry other materials in smaller sizes though. The McMaster interface is almost always VERY useful at narrowing down what's available based on you needs. For example, I quickly found the PTFE balls which come in smaller sizes: 

http://www.mcmaster.com/#plastic-balls/=87v64r 

Also, these Poly-imide balls may serve, they have a high temperature range... 

http://www.mcmaster.com/#plastic-balls/=87v5zy 

Just a thought... 

Trot, the well-rounded, fox...


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