In the world of process safety, we live by our chosen and adopted Recognized and Generally Accepted Good Engineering Practice(s) (RAGAGEP) and when our HHC/EHS is Chlorine (Cl2) we turn to the Chlorine Institute and their “Pamphlets” for our needs. And one of their most-used pamphlets is Pamphlet 6 – Piping Systems for Dry Chlorine. Note: The Chlorine Institute makes most of their Pamphlets available for FREE. In Pamphlet 6 the Chlorine Institute established six (6) service classes for Dry Chlorine piping. The end-user can easily use the table in Chapter 2 to determine which service class they need to build their chlorine piping to.