A(n) ___ sensor is a flame sensor that senses light frequencies that are higher than those visible to the eye.

Additional components that may be encountered with cooling systems are liquid receivers, accumulators, and purge units.

Additional components that may be encountered with cooling systems are liquid receivers, accumulators, and purge units.

An internal furnace is a furnace in a boiler that is surrounded by a heating surface.

A pressure control must be mounted in a vertical position to ensure accurate operation.

An ammonia-water chiller system commonly includes a generator, condenser, evaporator, and absorber.

A pressure control must be mounted in a vertical position to ensure accurate operation.

A ___ is burner control equipment that monitors the burner start-up sequence and the main flame during normal operation.

A ___ is an auxiliary device commonly used with boilers to transfer heat from a hotter fluid to a cooler fluid.

Only watertube boilers have bottom blowdown valves.