On Wed, 19 May 2021 07:18:38 +0100, Richard Smith
wrote:



The set pressure of opening means you reach an aim maximum tension in
the sample.
That that valve stays fully open until the hydraulic pressure drops to
(very near) zero completely unloads the sample to no load.
The valve closes and the cycle repeats, etc.

Does such a valve exist?

Look at "sequence valves."

For example:
http://valveproducts.net/pressure-se...sequence-valve


Rich Smith

--
Ned Simmons