a standard, model, or pattern. 2. general level or average: Two cars per family is the norm in most suburban communities. 3. Education. a designated standard of average performance of people of a given age, background, etc. a standard based on the past average performance of a given individual.
For example, pressure regulators are used in gas grills to regulate propane, in home heating furnaces to regulate natural gases, in medical and dental equipment to regulate oxygen and anesthesia gases, in pneumatic automation systems to regulate compressed air, in engines to regulate fuel and in fuel cells to regulate hydrogen.
In summary, the purpose of a propane regulator is to bottleneck the propane down to a safe and usable pressure. An important point to note is that under normal operation, a propane regulator will make a humming noise. This is normal and should not be construed as a problem or regulator malfunction.