cast iron piston ring leakage table
cast iron piston ring leakage table
(OP)
Does anyone know where I can get leakage infromation for cast iron piston rings in large hydraulic service?
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cast iron piston ring leakage table
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RE: cast iron piston ring leakage table
www.fpweb.com
Some of the companies that make piston rings should have info on bypass.
I was told many years back that a Rule of Thumb was:
One Cubic Inch/Minute per Inch of bore per 1000 PSI.
There are several designs of piston rings that would appear to have lower bypass but I have had very little experience with Piston Ring cylinders.
Work with a couple of 50" bore hydraulic presses locally that appear to take about 20-25 GPM to keep them in the up position, at 850-900 PSI, between cycles. They were built id 1953 and have never had to be repaired.
Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING, INC.
http://www.fluidpower1.us
RE: cast iron piston ring leakage table
http://www.hydra-seal.com/Piston_Rings.htm
Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING, INC.
http://www.fluidpower1.us
RE: cast iron piston ring leakage table
I think your hydraulic presses leakage is high but within reason.
When applying your rule of thumb to your presses I get a theoretical leakage of about 0.2 gal per min?
Am I missing something?
Bryan
RE: cast iron piston ring leakage table
I got my figure from knowing there are two 185 GPM Bi-directional Variable Volume Pumps that have a total stroke of approximately 5/8" either side of center and must be offset approximately 1/32" each to keep the Platen from drifting down when the oil is up to operating temperature.
From some old literature on the presses they state there is 5/8-3/4" end gap on the four piston rings when assembled and the presses operate 3 shifts per day 5 days per week about 50 weeks per year for a 60-70 second total cycle time .
You can figure the number of feet of piston travel for a 6' stroke during that length of time.
Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING, INC.
http://www.fluidpower1.us