Apco Combination Air Valve:  The combination air valve can be used by pipline contractors to purge air from a pipeline after a new pipeline is installed.  It allows large volumes of air to escape the water line when filling a pipeline with water.  It can also be used when a pump is used to pump water.  It was purchased new, never installed.  The retail price of the valve is $300., selling for $150., no haggle price.  In Escondido, call (760)746-7209