scope:

This Recommended Practice is intended to assist the designer or engineer in the definition of piping requirements for pneumatic signals and supplies in control centers. This Recommended Practice is based on current practices. Because of the special nature of each control center, specific rules are not practical and accepted guidelines should take precedence. This Recommended Practice is a presentation of these guidelines.

Piping external to the control center (Field Piping) is beyond the scope of this document.