Multi-level rotary plug valve

A fluid delivery system, comprising

• a heat exchanger,
• a rotary plug valve that delivers fluid to the heat exchanger in certain configurations of the rotary plug valve, and
• a pump disposed in a fluid line between the heat exchanger and the rotary plug valve, the fluid pump configured to drive fluid through the fluid deliver system,
• the rotary plug valve including
• a valve body including
• a body sidewall that encircles and is centered on a body axis,
• a body base that closes one end of the body sidewall, the body sidewall and body base cooperating to define a valve body chamber, and
• valve ports, each valve port communicating with the valve body chamber;
• and
• a valve plug assembly that is disposed in the valve body chamber, the valve plug assembly including a valve plug that is rotatable relative to the valve body about a rotational axis that coincides with the body axis, the valve plug including:
• a first plug portion that includes
• a first sidewall that encircles, and is centered on, the rotational axis, the first sidewall including an alpha opening,
• a first base that closes one end of the first sidewall, the first base having a first surface that faces the body base, and a second surface that faces away from the body base,
• a projection that protrudes from the first surface of the first base and intersects the first sidewall, the projection together with the first sidewall defining a beta opening that is spaced apart from the alpha opening along a circumference of the first sidewall,
• a first fluid passage that extends between the alpha opening and the beta opening;
• and
• a second plug portion that includes
• a second sidewall that encircles and is centered on the rotational axis, the second sidewall including a gamma opening and a recess, and
• a second base that closes one end of the second sidewall,
• wherein
• the second plug portion is disposed between the first plug portion and the body base, and
• the projection is disposed in, and engaged with, the recess in such a way that the first plug portion and the second plug portion are fixed relative to each other and are rotatable about the rotational axis together as a single unit.