For selection of ESD valve actuator supply, what are factors that decide whether ESD valve shall be hydraulic or pneumatic?

I am new to posting on this forum, but have been reading for a while. Very good page i must say :)Back to the question. We have some gate valves that are going to be ordered.

I am working on a project specs and it asks for butterfly valve with dry shaft design. Media is seawater. As I searched on the web, I saw that mostly concentric btv vendors are naming their product as

I'm looking for a source for a ball valve (class 150 flanged, metal body, pTFE seats) with an unusual shaped ball.

When a valve is newly manufactured I can understand why it needs a full pressure test to ensure the integrity of the casting or forging and to proove the pressure containment ability.

HiI'll try to briefly describe my problem: My hydraulic circuit (the pumps are supplying 130 bars of pressure) consists of a closed-center proportional valve that drives a hydraulic motor (which is us

I'm not too familiar with ARV's however I know the basic principle behind how ARV's work.

Seems simple but I am looking for some software to help calculate the linkage geometry needed to linearize different size butterfly valves driven by a motorized actuator.