The cold air modulating valve is mounted on the air-to-coolant heat exchanger. It varies the flow of refrigeration system air to the heat exchanger. The valve has a butterfly, a diaphragm-type pneumatic actuator that is mechanically linked to the butterfly, an electro-magnetic torque motor, and butterfly position switches. Electrical signals from the missile controller govern the torque motor, which allows regulated air pressure to be vented. The smaller the amount of air pressure vented, the larger the valve opening. If the electrical power or air pressure is interrupted, the valve closes.

Missile Hot Air Modulating Valve

The missile hot air modulating valve is mounted on the air-to-coolant heat exchanger. The valve varies the flow of hot air from the 400 F bleed manifold temperature control system in response to electrical signals from the controller. The hot air heats the coolant during system warm-up. The operation of the valve is the same as the missile cold air modulating valve.

Missile Air-to-Coolant Heat Exchanger

The air-to-coolant heat exchanger consists of two sections: weapons control system (radar) loop, and missile loop. The heat exchanger is similar to an automobile radiator. The coolant flows through the core while air flows around the core. When the radar portion of the heat exchanger is being used, the missile cold and hot air modulating valves are closed to prevent reverse flow through the missile section.

Missile Coolant Pump

The coolant pump is a single-stage, centrifugal pump driven by a low-slip, two-pole induction motor. When the pump is operating, it circulates 18 gallons of coolant per minute through the system. The pump is lubricated and cooled by a small portion of the coolant, which is circulated through the motor. A pressure switch in the pump outlet opens when the pump output pressure drops to 60 5 psi. The pressure switch causes the MSL COND (missile condition) advisory light to illuminate. Also, a thermal switch will open when 230 5 F is reached. This switch causes the pump to stop and also illuminates the MSL COND light. The coolant pump is located in the right Phoenix fairing.

Coolant Fluid Expansion Tank

The expansion tank is located in the right Phoenix fairing. The tank maintains a constant coolant fluid pressure at the pump inlet, accommodates thermal expansion of the coolant, and provides a coolant reserve for the missile loop in case of leakage. The tank has a bellows, fluid sight and level indicator, fluid relief valve, and a pneumatic pressure indicator. The bellows is pressurized to maintain a positive fluid pressure of 30 to 37 psi at the pump inlet. Should pressurization reach 45.0 2.3 psi, the fluid pressure relief valve will open and vent fluid. The fluid sight and level indicator displays fluid level, and the pneumatic pressure indicator extends to indicate air pressure by temperature degrees.

Missile Bypass Valve

The missile bypass valve is located at fuselage station 372. It is used to bypass the missile when the fluid pressure within the missile reaches 89 + 0, - 5 psid. When this condition exists, the bypass valve opens. This allows a portion of the coolant fluid to flow from the supply line to the return line without passing through the missile.

Missile Air-Moisture-Contaminant Remover

The remover is mounted in the right Phoenix fairing. It removes air, moisture, and foreign particles from the coolant, but it does not remove standing water. The remover consists of a cleanable filter element, a replaceable removal cartridge, a fail-safe valve and indicator, a relief valve, and an automatic shutoff valve. If the removal cartridge fails, the fail-safe valve prevents coolant loss by securing the air-water removal overboard port. If this occurs, a yellow indicator button is released to warn of cartridge failure. If the pressure drop across the filter element exceeds 16 3 psi, the red differential pressure indicator button extends to warn of a clogged filter. If the pressure drop exceeds 21 to 25 psi, the relief valve passes coolant around the filter element. When the filter bowl is removed, an automatic shutoff valve closes to prevent loss of coolant.

Missile Controller

The controller is the brain of the liquid cool-ing system. It receives electrical input from the sensors and controls component operation. It keeps the hot and cold air modulating valves from opening at the same time. The controller also provides electrical signals to the naval flight officer (NFO) caution advisory indicator.