The Plumbing & Drainage Institute (PDI) is an association of American manufacturers of engineered plumbing drainage specialty products.
[2] The Institute's objective is to promote the advancement of Engineered Plumbing Products through research and standardization of product requirements; to prepare, edit, and publish standards relating to plumbing products; and to provide certified testing, rating, and installation procedures for grease interceptors and water hammer arresters, in Standards PDI-G101 and PDI-WH201, respectively.
Certified Products carry the Seal of the Plumbing & Drainage Institute as evidence that the product has met the specified requirements of the Institute’s Standards.
[1] [3] PDI assists with the development of National Standards through the ASME Committee of the American Society of Mechanical Engineers.
This is the consensus group for ANSI (American National Standards Institute).