IP converters for gas can be valuable tools in controlling the flow of gas in applications such as gas distribution networks. By controlling the output pressure of the gas, they can deliver the correct gas volumes precisely where it is needed for use. This can not only save on gas costs, it is also valuable in terms of safety by preventing potentially dangerous gas from venting to the environment. To ensure these performance objectives are met, it is very important to ensure that the right proportional gas valve is selected.
How does the Type 422 IP convertor for gas operate?
Input air is bled to a solenoid valve, which acts as a pilot opening and closing as required to adjust the pressure required to operate a control volume. The control volume and base valve in turn controls the output pressure.
An output valve vents air which in turn reduces pressure in the control volume, closes the base valve and decrease the output pressure. The proportional valves, which are controlled by the closed loop control circuit, monitors the demand input and the actual output pressure of the valve.
What does Fail Freeze functionality mean?
Put simply, ‘fail freeze’ functionality occurs when there is a power cut and the input signal drops or disappears causing both solenoid valves to close. When this happens, pressure is trapped in the control volume and holds the base valve in position. The Watson Smith model 422 IP converter performs ‘fail freeze’ functionality by retaining its last input signal to ensure continuity of gas flow. The gas therefore, will remain at a constant pressure based on the last signal received and only change the IP position to the new position when the power is restored and the signal changes.
The Type 422 is the only ATEX certified fail freeze proportional valve for natural gases on the market. It has been certified and provides the flexibility to safely use potentially flammable gases to pilot the applications.The IP Converter for gas Type 422 ‘fail freeze’ valve is now available and provides the opportunity to remove the need and cost of installing a pneumatic system.