Reference Material is not Always Accurate!
PV Publishing provides products for the process industries to help users with their day-to-day job duties and activities.  Although we go to great lengths to make sure our products are accurate we do not guarantee there accuracy.  We recommend you verify the information and calculations obtained from any product we provide, as well as, any product provided from other sources you may use for reference material.  Due to the inherently dangerous nature of the industries we serve it is highly recommended that you verifying the accuracy of any product you utilize to perform your professional duties.