Model JZ dual-purpose pneumatic qneumatic quick-closing is designed to be used in marine piping systems. The valve can be used an ordinary shut off valve in normal times. Moreover, it can be opened and closed by a hand wheel just like an ordinary shut off valve. In case of emergency, emergency action can be made either manually or pneumatically to cause the valve to be closed immediately. The emergeney action can be remote and central controled, if the controlbox the quick-closingvalve is used.