CSA America has issued an addendum to standards covering pressure relief devices in the US. Some of the more important changes to the standard are:

•    New definitions for "Manufacturer's Specified Activation Temperature" and "Manufacturer's Specified Service Pressure."
•    The minimum design life of PRDs has been increased from 15,000 to 20,000 cycles.
•    Aluminum has been added as an acceptable material for PRD housings.
•    A table has been added to simplify the determination of which tests are necessary for new designs and design changes.
•    The amount of leakage permitted in the leakage test has been lowered from 2.0 scc/hr to 0.2 scc/hr.

Copies of the new addendum are available from CSA for $72.  Go to http://www.csa-intl.org/onlinestore/, and click on the appropriate line for US and International customers or Canadian customers.  Then put "PRD 1" (DO include the space) in the "Search" box and the first item that comes up is the PRD1B-2007 addendum.  If you are a member of CSA's "Participation Program," CSA standards are available at no cost.  Go to  http://www.csa-america.org/ , click on "Participation Program," scroll down to "Already a Participant? Login Here" near the bottom, and log in to the "Participant Private Area."  Then click on "Standards Publications" on the left and scroll down to "PRD 1b-2007.pdf" to download the addendum.