NSC-National Sales Company was founded in 1946 & is headquartered in St Louis MO. NSC is a third generation family owned wholesale distributor of pipe, valves, fittings & everything related for the mechanical/HVAC contractor, commercial plumber, and industrial & institutional facility technician. In 2014, NSC began the Applied Products Group which focuses on the application of HVAC equipment for the commercial, industrial and residential markets.