On Wed, 7 Mar 2012 02:40:18 -0500, "Tom Gardner"
wrote:

I have a flow control valve like this:
http://www.grainger.com/Grainger/PAR...789?Pid=search
It controls the speed of a 2x10 cylinder and the movement of the cylinder
and mechanism is making the adjustment knob move so the cylinder gets faster
and faster. It does have a set screw that will lock the adjustment knob but
the operator needs to change it often and during the stroke. Is there a
simple way to stiffen the knob without locking it? (Yes, I could get a new
one.)

Can you live with two-speed rather than variable speed? Plumb in a
parallel circuit with another adjustable valve and a quarter-turn ball
valve. With the new circuit closed, adjust for low speed. With it
open, adjust for high speed. Lock both adjustable valves in place. The
only moving part would then be the ball valve.