After his innovations in the railroad industry, Westinghouse settled in Philadelphia, where he had a natural gas well drilled on his property. The well allowed Westinghouse to work on his next great invention: a valve that allowed for the safe distribution of natural gas to homes.
There's a problem with using natural gas for fuel at home: The gas is highly pressurized when it leaves the well -- it has to be in order to move the gas through distribution pipes. But what you don't want is highly pressurized gas coming out of the end of the line into someone's home. It just isn't safe.
To solve the problem, Westinghouse invented a reduction valve that allowed natural gas to come out of its distribution pipes in low-pressure bursts. As a result, natural gas became safe enough for home use -- and Pittsburgh soon had the nation's first wide-spread natural gas delivery system.
But Westinghouse is more widely known for his work with electrical power, which led to his rivalry with Thomas Edison.