Editor’s Note: This is the second in a multi-part series about the Online Piping and Usage Specification (OPUS) resource available from the Mechanical Contractors Association of America (MCAA).

In the October issue of Plumbing & Mechanical, the Online Piping and Usage Specification (OPUS) website, www.opuspiping.org, was introduced as a resource for basic information regarding common piping systems, materials and joining methods. The purpose of that article was to introduce readers to the breadth and depth of the piping industry, with its vast array of options supported by an even greater range of information. OPUS serves, in Swiss-Army-knife fashion, as an indispensable portal to that voluminous information.