<ul><li>Used if any air source or air supply piping line failure occurs in the air operated process control line</li><li>Three options: Single acting, Double acting, 3 Port</li><li>Double acting: Retains pressure at the operating area as emergency operation until the air source is recovered to its normal state</li><li>3 Port: Changes the supply port if a trouble occurs</li><li>Port Size: 1/4</li><li>Options: High (-5 to 100 °C) / Low Temperature (-30 to 60 °C) / External parts cooper-free.</li></ul>