This paper will review the fundamentals of pressure regulators as used the natural gas industry. The word regulator as defined by Webster is; 1: a person or thing that regulators, 2: a mechanism for controlling the movement of machinery, fluids gasses, etc. In this paper we will look at the second definition of the word and talk about a mechanical devices that are used for pressure regulators. There are two main types of regulators used with natural gas pressure reducing regulators and backpressure regulators (also referred to as relief regulators)