NATIONAL BOARD " REDBOOK"

Pressure Relief Device Certifications

NB-18

This publication includes:

a complete listing of and information pertaining to the device designs certified by the National Board.

certifications issued to pressure relief device manufacturers and assemblers, thereby granting permission to apply the National Board "NB" and construction code symbols.

listing of combination capacity factors determined for various rupture disk devices installed in series with pressure relief valves.

companies holding "VR" Certificates of Authorization for the repair of pressure relief valves are also listed.

The online Pressure Relief Device Certifications are updated once a month, making it easier to access the most current information available. Because the NB-18 is presented in a portable document format (PDF), it will be necessary to obtain and use Adobe Reader. Once this file is downloaded, the NB-18 may be used in an electronic format or printed as desired.