I need to make a new piston ring for a Campbell Hausfeld oil free air compressor. I have this handy little portable tank mounted 110 volt air compressor. On the weekend it "failed to perform" and upon disassembly I found the piston ring is worn out. Parts are not available. So I need to make a new piston ring. Piston and cylinder and valves all seem fine. The existing one is a tan coloured plastic. I'm thinking I will try Teflon. Nylon is another option. Your thoughts?
The oil free compressors never last very long because they don't have lubrication. I would concentrate my efforts on replacing the compressor with a more reliable type that has lubrication. One of those that lasts forever if cared for properly.
With out more information - I did a quick name search and found this on the Summit Racing page: http://www.summitracing.com/parts/cam-wl200401sj?seid=srese1&gclid=CLS-lrfsq8gCF cEXHwodqRUCEQ
Also it appears Sears may sell parts?
Teflon is too fluid to be used as a piston ring, although it's good as a packing material. Maybe some graphite carbon fiber material would work.
we used Teflon rings in steel forge hammers for the last 45 years don't see why this cant be done
Koppers used and may still make glass filled Teflon piston rings. Kidde used them 40 years ago in their 3000 psi air compressors. They used a flat stainless steel expander behind the Teflon ring. You could make the parts on the lathe and hand form the expander by hand. You might use beryllium copper for the expander.
Thank you for all the interesting responses
Royce. This compressor is just so darn handy. I can carry it in one hand and my nail gun in the other hand
I talked to a very experienced Machinest friend and he recommends Teflon and in fact gave me a piece to try!!!
Again thanks for the replies
The glass filled Teflon rings used a lap joint. We used these rings in an air powered multi section antenna mast. Our shop made the rings and a contoured knife blade to make the lap joint
Its been over 20 years since I messed with oil free compressors but I think the rings were made of UHMW polyethylene. Teflon will not work as it is soft and will extrude.
By the way the oil free compressors I worked on were in the 150 to 200 HP range and pumped 450 to 600 psi at around 1500 cfm. They were 3 stage compressors and the high stage rings had to be replaced yearly when used around the clock for the year. The second stage rings had to be replaced every other year and you guessed it the first stage rings needed to be replaced every 3 years. These compressors were used to produce food grade plastic bottles.
Les, I had a similar problem with my compressor. Found the correct parts from this company: