Shutt off pressure in control valve?

If I take a 2000 pound pressure air cylinder and connect it to some 5000 psi tubing and add a shut off valve good to 1000 psi on the end of this 5000 psi tubing, I may well blow the valve apart when I try to shut it off.

The shutoff valve should have a max pressure at least 50% higher than anything it will face in use, so it will not blow off the face of world

If you are referring to a pneumatic air to open, diaphragm actuated plug valve. When the process pressure differential is higher than the valves shut off pressure rating, the process pressure can overcome the force of the spring that is supposed to hold the plug against the valve seat. In this situation the valve will not shut off.

With this type of control valve max working pressure rating is usually not the same as max shutoff pressure.

It should be the same as conventional valves, the max shutoff pressure stands for when you close the port of the valve the conversion of velocity+static pressure it is converted to fulll static pressure, this pressure should be less than the max shut off..

I hope this clarify your request