Leather vs Delrin for piston seals

markkw · Oct 24, 2016

Not a tractor, it's an old Flint & Walling piston pump and I hope this post doesn't ruffle any feathers as it's not my intent.

I'm going to be rebuilding this pump to use as a working model. The original cups on the piston and seals on the check valves are made from leather. I'm curious as to if anyone has machined piston cups from Delrin, and if so, does it get a thumbs-up or thumbs-down in comparison to leather cups?

Thanks,
Mark

Mike M · Oct 24, 2016

I'd just go to a hyd. supplier and get leather cups. Or depending on size I have found rubber brake cylinder cups at the auto parts stores too.

Steve@Advance · Oct 24, 2016

Isn't Delrin quite hard, some type of plastic if I remember? That might be hard on the cylinder and would quickly melt if ever run dry.

There are several ready made piston cup blanks available. Not sure what it is called, but one is a neoprene embedded cloth type material made for oil, but would work with water. The other option would be to just go back with leather. It will last a long time, especially used as a model. Look on Youtube, there is a video of how to make them

Then you can say "I made my own piston cup"!

flembo · Oct 24, 2016

Yes delrin would be to hard for a seal I would think. I machine a lot of delrin for machine parts where wear is an issue.

markkw · Oct 25, 2016

I was just curious if anyone has used them in water pumps. Years back I changed leather cups to
Delrin in high pressure (165 psig) piston pumps used for delivering ink to a printing machine. I
found where I can buy the leather cups and will likely just use them. I do appreciate the input.
Thank you all.

Leather vs Delrin for piston seals

markkw

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Mike M

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Steve@Advance

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flembo

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markkw

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