Process flow diagram - Typical oil refinery. This is a schematic process flow diagram of the processes used in a typical oil refinery. This process flow diagram (PFD) example was redesigned from the Wikimedia Commons file: RefineryFlow.png. [commons.wikimedia.org/wiki/File:RefineryFlow.png] This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
Each gym also provides its members with access to state-of-the-art equipment. While members need to be 18 years old to sign up individually, those who are at least 14 can sign up with a parent or legal guardian.
Prerequisites vary by the organization, but candidates for fitness trainer certification usually must be at least 18 years old and possess both CPR and AED certifications to qualify. Some organizations require candidates to hold a high school diploma or the equivalent, but many have no educational prerequisites.