If a ANSI 600 gate valve was initailly manufactured say for example in 1990, the maximum design pressure at 100 Deg F would have been 1440 psig.

An English version paper about the introduction of GATE VALVE, better it's a academic one. actually this is special for a guy of my colleague's younger brother as reference.

To calculate the closing/opening time of a Gate valve using an hydraulic actuator. What are the input parameters required and what is the formula for this calculation?

An inspection of input voltage vs flow rate properties of a hydraulic servo valve Im impressing a triangular wave (frequency 0.01Hz amplitude +-10v) and plotting voltage and flow on an X Y graph.

A full bore (or full port) valve is one where the hole in the ball is equal in diameter to the hole in the pipe.

Explain the usage of the adjustable port valves? By adjusting the port size, we can change the valve capacity, To restrict the flow (when fully open) to a very low level, do we need a restrict orifice

A trim 12 valve cannot by nature meet that spec, and therefore they should have ordered something else.

Expanding conduit Gate Valves for the well section and some vendors quoted metal seats some quoted r-ptfe seats.