The nominal pipe size refers to the diameter of a pipe.
The Pressure/vacuum relief valve Pressure/vacuum relief valve is an umbrella term that includes pressure or vacuum relief valve as well as pressure and vacuum relief valve. diameter determines the size of the pipe and the quantity of liquids and gases flowing through it. A nominal pipe size Nominal pipe size The nominal pipe size refers to the diameter of a pipe. that is too small can impede flow, while a nominal pipe size that is too large can result in higher energy consumption.