Abstract: A combination solenoid operated flow control valve and solenoid operated by-pass valve and pressure transducer are disposed in a common housing with a common electrical receptacle for connection thereto. The pressure transducer senses differential pressure across a metering orifice. The pressure transducer measures flow through the metering orifice during leak testing. A vacuum is drawn in the system for leak testing. The by-pass valve is opened to bypass the metering orifice and permit full flow to the flow control valve during normal engine operation.

Abstract: A combination solenoid operated flow control valve and solenoid operated by-pass valve and pressure transducer are disposed in a common housing with a common electrical receptacle for connection thereto. The pressure transducer senses differential pressure across a metering orifice. The pressure transducer measures flow through the metering orifice during leak testing. A vacuum is drawn in the system for leak testing. The by-pass valve is opened to bypass the metering orifice and permit full flow to the flow control valve during normal engine operation.

Abstract: A solenoid operated valve suitable for controlling flow of air for injection into the exhaust of an engine, the poppet is connected to the solenoid armature in a lost-motion connection. Upon energization, the armature achieves momentum during the lost-motion movement and imports an impulse to the poppet to ensure movement in the event of any tendency of the poppet to stick. A one-way valve prevents exhaust back pressure from opening the poppet.