What term is used to determine a reduction in pipe size based on probable use rather than full use of a gas system?

The term that describes a reduction in pipe size based on probable use rather than the system being utilized to its full capacity is known as the diversity factor. This concept accounts for the varying and non-simultaneous demand for gas in a system. In a typical gas supply scenario, not all connected appliances or fixtures will be operating at maximum capacity at the same time. Therefore, the diversity factor allows for a more efficient sizing of the piping system, considering that some devices may be in use while others are not.

By applying the diversity factor, engineers and designers can optimize the design of gas systems to avoid oversizing pipes, which would lead to increased material costs and potentially inefficient operation. This principle is essential in creating a balance between safety, efficiency, and cost in gas system installations.

In contrast, other options such as the compression factor, sizing factor, and flow factor refer to different aspects related to gas systems but do not specifically address the concept of varying usage levels among multiple appliances.