Control valve accuracy
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Hello everyone, I have a question. There is a hydrogen pipeline with DN350, a maximum flow rate of 6750 Nm3/h, and a normal flow rate of 5000 Nm3/h. The pressure before the valve is 60 kPa, and the pressure after the valve is 0 KPa. The control valve is regulated via a pressure transmitter on the hydrogen distribution station. I selected a control valve with a valve body of DN250 and a valve seat of DN125. If I want to ensure a precise pressure of 60 KPA, does it suffice to choose a regulator with higher precision? What is the typical accuracy of a locator? Thank you all
This is related to the principle of the positioner; from a practical perspective, intelligent valve positioners (such as piezoelectric types) offer higher adjustment accuracy compared to mechanical ones (with nozzle dampers).
What is the adjustment accuracy?
Taking the Yamaki AVP302 as an example, 8 mA ≤ input signal range
Preferred option: Intelligent valve positioners. Piezoelectric positioners work well for large-diameter valves; however, they present issues with small-diameter valves, especially those from Siemens – air leakage still occurs even when the air supply lines are leak-free. Nozzles with shut-off plates consume more air but are more durable. The choice of valve diameter is also important. The typical operating range is between 30% and 85%