I've been asked to investigate different styles of hydraulic valves for use by a customer.
One of the styles that has been discussed, I can't find any info on, not helped by no-one knowing what its called. So I'll describe it:
Imagine a length of rubber hose with fluid flowing through it. If you twist it (and constrain it correctly) it will twist tighter and tighter, restricting and finalling stopping flow, depending on the flexibility of the rubber and the viscosity etc of the fluid. A bit like making party balloon animal.
Apprently, they're used in the oil industry on surprisingly big pipes. Anyone know what I'm talking about?