IMI Precision Engineering has presented the world's only "Fail Freeze" proportional valve (pressure-maintaining in the event of a fault in the supply voltage) that is certified according to Atex (IS) for use in hazardous environments. The valve of the 422IS series allows the use of flammable gases as a control medium instead of compressed air. This makes compressed air generation at remote locations unnecessary.

The IMI Norgren brand valve already regulates the safe and uninterrupted supply of gas to some of Britain's largest cities. Even in the event of a power failure or a signal fault, the last set output pressure is precisely maintained.

The 422IS Fail Freeze Proportional Valve can be operated in a temperature range from -10 ° to + 70 ° C with a supply pressure of 4 bar. It consumes no current when adjusted and less than 0,15 W when output pressure changes. For best performance, linearity and hysteresis are designed to be less than 0,5% of the maximum settable output pressure. Vibration and mounting position have almost no influence on the control behavior of the valve.

Stephen Turner, Product Manager at IMI Precision Engineering, explains: "For many chemical and process engineering applications, uniform control pressure is essential. In many processes, unexpectedly closing a control valve can at least lead to loss of the end product - in some cases it can unsafe conditions, such as a back pressure in the gas pressure system. The 422IS limits these risks and avoids the risk of overpressure. This allows designers to eliminate the risk directly at the source. "

The Atex-IS certification eliminates the need to install additional pneumatic systems on site. The gas as the control medium can be taken directly from the pipeline. Thus, the 422IS shortens the commissioning and reduces the operating and maintenance costs of the entire system.