Patent ID: 8567201
Filing Date: 2013-10-29
Classification: F02C

Abstract:
1. An ecology valve for draining and storing fuel from a manifold of a gas turbine engine, the ecology valve comprising: a housing defining a piston interior having a run side shoulder and a shutdown side shoulder defining an opening opposing the run side shoulder, a first port in fluid communication with a fuel pump metering unit (FPMU) for receiving fuel output from the FPMU, and a second port in fluid communication with the manifold; a piston mounted for sliding movement within the piston interior between a run position and a drain position, the piston having a shaft and a head portion, the head portion partitioning the piston interior into first and second pressure zones, the first pressure zone being in fluid communication with the first port and the second pressure zone being in fluid communication with the second port, the head portion also defining a passage for fuel flow between the first and second pressure zones of the piston interior, wherein in the run position, the head portion of the piston is against the run side shoulder with the shaft at least partially in the piston interior such that the piston interior contains a first volume of fuel, and in the drain position, the head portion moves away from the run side shoulder against the shutdown side shoulder so that the shaft extends further through the opening such that the piston interior contains a second volume of fuel, the second volume being greater than the first volume due to the shaft of the piston extending further through the opening; and a spring coupled between the housing and the piston to normally bias the piston in the drain position.