Abstract: A system and method provide dual level pressurization control of a fuel supply system based on whether fuel is being supplied to one or more secondary fuel loads. Fuel pump discharge backpressure is maintained above either a first minimum pressure value or a lower second minimum pressure value by determining whether fuel is being supplied to one or more secondary fuel loads. The fuel pump discharge pressure is maintained above the first minimum pressure value if it is determined that fuel is being supplied to the one or more secondary loads. The fuel pump discharge backpressure is maintained above the lower second minimum pressure value if it is determined that fuel is not being supplied to the one or more secondary loads.

Abstract: A system and method provide dual level pressurization control of a fuel supply system based on whether fuel is being supplied to one or more secondary fuel loads. Fuel pump discharge backpressure is maintained above either a first minimum pressure value or a lower second minimum pressure value by determining whether fuel is being supplied to one or more secondary fuel loads. The fuel pump discharge pressure is maintained above the first minimum pressure value if it is determined that fuel is being supplied to the one or more secondary loads. The fuel pump discharge backpressure is maintained above the lower second minimum pressure value if it is determined that fuel is not being supplied to the one or more secondary loads.

Abstract: A fuel control system for a gas turbine engine is disclosed that includes a flow path carrying fuel from a fuel source to a combustion chamber, an ecology valve 124 for removing a quantity of fuel from the flow path, the ecology valve 124 being shiftable in a first direction from a first position to a second position and in a second direction from said second position to said first position and a fuel line 115 connected between the flow path and the ecology valve 124 for moving fuel between the flow path and the ecology valve 124 to bias the ecology valve 124 toward the second position, where the fuel line 115 is configured, such as by the inclusion of an orificed check valve 150 therein, to allow fuel to move therethrough away from the ecology valve 124 at a greater rate than toward the ecology valve 124.

Abstract: A control system (10) for a limited stall load actuator (60) comprises a servo pressure regulator (20), solenoid valve (40), relief valve (30) and a shuttle valve (50) connected with a piston actuator 60 such that when source pressure P1 is declining the servo pressure regulator (20) will open to permit more flow and maintain a minimum actuation force effected by the actuator (60), and should there occur a failure of the servo pressure regulator (20) that would permit high source pressure to be communicated to the control system (10), the relief valve (30) will operate to limit the amount of high pressure communicated to the control system (10) such that the actuator (60) will attain no greater than a predetermined maximum output force.

Abstract: An overlapped test specimen fixture operates as a template to precisely position pairs of standardized coupons in predetermined overlapped relation to demarcate standardized bonding sites for application of adhesive systems to be tested. The fixture includes a caul plate bounded by an integral, elevated shoulder having opposed sidewalls and endwalls. The exposed surface is configured as a bi-level, flat support surface having upper and lower surfaces that support the coupons in overlapping relation. The opposed sidewalls are operative to precisely position overlapped coupons lengthwise wherein such coupons demarcate a predetermined overlap length. The fixture also includes locator rails extending upwardly from support surfaces which are operative to precisely position the overlapped coupons transversely. The precisely positioned, overlapped coupons define standardized bonding sites for application of the adhesive system to form a test specimen.