62 preferably of a ferrous metal which is mounted to an elongated indicator rod 64 the indicator rod 64 extends along the piston axis 34 through a sealed opening in the end cap 18 and the tubular body 40 of the piston 36 one end is threaded into the back of the poppet valve 38 and the other end fits through an opening in housing 16 to extend outside the valve body when in the open position of fig4 this end provides visual indication of the state of the valve as mentioned the preferred application for the valve of the present invention is in the drain system for a gas turbine engine specifically the valve is designed to isolate a combustion chamber or can of the engine from the drain so that engine compression can be maintained during normal operation in which conventional engines burn gaseous fuel typically there are several combustion cans for each turbine some conventional power generation turbine engines have 14 combustion cans coupled in upper and lower pairs thus a total of seven valves of the present invention would be used to control the draining of fuel from each of the seven combustion can pairs in any event the valve stays in the closed state shown.