Our reactor is cooled by a cooling water system. The line pressure is around 4 bars and the pipe size is 42. How to select a good valve for that service?
Specialty valves should be sized/recommended by the manufacturer because of the different influences that may be encountered by the valve. Example: Temperature ranges, chemical composition of coolant, type of valve(ball, gate, tempering, other) all will have some effect. I would say take a look at the old one if it exists and if you're not satisfied with its performance, then cross reference it with other companies like Amtrol, Wilkins, etc. This would be the safest most logical method.
You'd also need to know design flow ranges, ultimate flow desired, pressure drop acceptable across valve, and the average temperature of cooling water the valve will see or the range it will see if varies much. You would need to decide if you want to use a ball valve, butterfly valve, of a globe valve to throttle the water.
