Thrust-OK Pressure Switches
Three pressure switches, mounted on a single manifold located on the thrust chamber fuel manifold, sense fuel injection pressure. These thrust-OK pressure switches are used in the vehicle to indicate that all five engines are operating satisfactorily. И pressure in the fuel injection cavity decreases, the switches deactuate, breaking the contact and interrupting the thrust-OK output signal.
The pressurization system heats GOX and helium for vehicle tank pressurization. The pressurization system consists of a heat exchanger, a heat exchanger check valve, a LOX flowmeter, and various heat exchanger lines. The LOX source for the heat exchanger is tapped from the thrust chamber oxidizer dome, and the helium is supplied from the vehicle. LOX flows from the thrust chamber oxidizer dome through the heat exchanger check valve, LOX flowmeter, and the LOX line to the heat exchanger.
The heat exchanger heats GOX and helium with hot turbine exhaust gases, which pass through the heat exchanger over the coils. The heat exchanger consists of four oxidizer coils and two helium coils installed within the turbine exhaust duct. The heat exchanger is installed between the turbopump manifold outlet and the thrust chamber exhaust manifold inlet. The shell of the heat, exchanger contains a bellows assembly to compensate for thermal expansion during engine operation.
Heat Exchanger Check Valve
The heat exchanger check valve prevents GOX or
vehicle prepressurizing gases from flowing into the oxidizer dome. It consists of a line assembly
and a swing check valve assembly. It is installed between the thrust chamber oxidizer dome and the heat exchanger LOX inlet line.
The LOX flowmeter is a turbine-type, volumetric, liquid-flow transducer incorporating two pickup coils. Rotation of the LOX flowmeter turbine generates an alternating voltage at the output terminals of the pickup coils.
Heat Exchanger Lines
LOX and helium are routed to and from the heat exchanger through flexible lines. The GOX and helium lines terminate at the vehicle connect interface. The LOX line connects the heat exchanger to the heat exchanger check valve.