On March 9, 2007, the ANSI Board of Standard Review (BSR) approved Addendum No. 7 - 2007 to the Guide for Gas Transmission and Distribution Piping Systems - 2003 Edition. Addendum No. 7 contains 52 pages and is formatted to enable direct replacement of pages in your copy of the 2003 edition (when printed double-sided). The Addendum includes all revised federal regulations and new guide material developed since Addendum No. 6 was released in November 2006. To download your copy, click on "Addendum No. 7" under "Related Files". Purchasers of the 2003 edition will automatically receive a paper copy of Addendum No. 7. Click here to purchase your copy of the 2003 Guide.