Need to coralate C o F of valve seat material to torque
Need to coralate C o F of valve seat material to torque
(OP)
Is there a means or standard test that can realibly predict actuation torque for soft seated valve materials using the coefficent of friction value of a specific material?
Or is there a defined test that one could use to "sort" soft seated valve materials besides builing several valves from each material and preforming torque test on them?
Soupboy
Or is there a defined test that one could use to "sort" soft seated valve materials besides builing several valves from each material and preforming torque test on them?
Soupboy





RE: Need to coralate C o F of valve seat material to torque
But, so does the design of the seat/seal - seal preload, which depends on the modulus of the materials, and pressure loading if any, which depends on shutoff conditions and rigidity/fixity of the seal members, also play a part in determining what the "normal force" is that generates friction. Also any designed-in imbalance of pressure forces tending to hold a valve in the closed position.
RE: Need to coralate C o F of valve seat material to torque
After that you can use the equations on other valve sizes and get values that are quite relevant.
RE: Need to coralate C o F of valve seat material to torque
Can you do an incline plane test to determine the COF?
Once you have an angle on the incline plane, can you interpolate the force required to move the part?
If you know the force, can you use that to determine the torque?
Charlie
www.facsco.com
RE: Need to coralate C o F of valve seat material to torque
- More than a few thousand PSI and some stainless galls CF = real high
- If soft materials means elastomers etc then COF > 1 is pretty possible (witness the anecdotal stories of near disbelief when 1/4 mile drag strip speeds exceeded 200 mph ). The normal force of a test sled on an Inclined plane > 45 degrees vs gravitational force is varying a bit as the angle changes
Might be easier to test a few valves