"Salmon," notes writer Susan Ewing in The Great Alaska Nature Factbook, "pump through Alaska like blood through a heart, bringing rhythmic, circulating nourishment to land, animals and people".

This paper states the method of selecting and using circulating pump in hot water heating system properly to save electric energy.

There were some new problems such as the easy exhaustion of the liquid ammonia circulating pump and the appearance of liquid ammonia product was off specification.