May 29, 2000 USA ...rupture disks and related products Operating Ratio WEBSITE: http://www.zook.cc What is an “Operating Ratio ? Ratio”? ZOOK Rupture Disk Seminar 1 May 29, 2000 Operating Ratio All styles of rupture disks have an operating ratio. Based on a disks design, it will only withstand so much pressure before there is an effect on the disks main priority p y - to burst at the stamped rating. Operating above this pressure may shorten the disks life expectancy and may cause nuisance bursts. Disk Design Classifications and Operating Ratios All Graphite URA/SRA/SB SFAZ Operating Ratio 90% 90% 85% Fragmenting Non-Fragmenting Non-Fragmenting g g D/ProPos/ProVac PB ARD 80% 70% 50% Minimal Fragmenting Fragmenting Minimal Fragmenting Series ZOOK Rupture Disk Seminar Classification 2 May 29, 2000 Example: The URA disk design has a 90% operation ratio. ratio This means that you can safely operate up to 90% of the disks marked burst pressure before having an effect on the disks performance. If the disk has a –10% MDR and the specified burst rating is 100.00 psig, the disk will be marked between 90.00 and 100.00 psig. Therefore the max recommended operating pressure is 81.00 psig. OPERATING RATIO SPECIFIED BURST RATING MAWP 100 95 -10% MDR LOW SIDE OF MDR 90 85 90% OPERATING RATIO 80 75 ZOOK Rupture Disk Seminar 81 PSI MAX SAFE OPERATING PRESSURE 3 May 29, 2000 Click mouse or press enter to start animation. To replay click on “REPLAY” when slide is complete. To continue click on “CONTINUE”. Calculating the Operating Ratio SPECIFIED BURST RATING MAWP 100 Rupture disk will be marked somewhere within this range 95 -10% MDR Customer Specifies MAWP of 100.00 psig Customer Requests MDR of –10% 90 85 Calculate the Max safe operating 90% pressure based on lowest possible OPERATING marked burst rating RATIO LOW SIDE OF MDR 85 PSI OPERATING PRESSURE 81.00 PSIG 80 Customer Specifies 85.00 psig Disk (as specified) will not perform Process operating pressure to customers specifications REPLAY CONTINUE ZOOK Rupture Disk Seminar 75 4 May 29, 2000 Re-Calculating the Operating Ratio Rupture disk will be marked somewhere within this range SPECIFIED BURST RATING MAWP 100 -5% MDR LOW SIDE OF MDR 95 Adjust MDR to –5% 5% 90 90% Calculate the Max safe operating OPERATING pressure based on lowest possible RATIO marked burst rating 85.50 PSIG 85 PSI OPERATING PRESSURE 85 80 Disk will now perform to customers specifications 75 Safe Operating Range - SOR    Based on the disk type or options ordered ordered, the low end performance will be determined (usually either full vacuum or -0-). Calculate the “Maximum” safe operating pressure (specified burst pressure – low end MFG Range – disk operating ratio) ratio). These two figures are combined to supply a range of pressures that the disk will safely perform within, or the "safe operating range". ZOOK Rupture Disk Seminar 5 May 29, 2000 Example D-V D V series disk rated 100.00 100 00 psig with standard MFG range of -5/+9 psi. Determine the low end of range:  Because disk style has a vacuum support, the low end of SOR = full vacuum. Calculate the high end of range:  100.00 psi – 5.00 psi = 95.00 psi  “D” series disk has an 80% operating ratio.  95.00 psi – 20% = 76.00 psi Combine the two for full range: Safe Operating Range: full vacuum to 76.00 psi Available tools    ZOOK Rupture Disk Seminar Specification forms (available from ZOOK). Forms act as an excellent guide to gathering required information OR ZOOK website – great for interactive phone discussions discussions. OR Send us design spec sheets – we will do the rest! 6 May 29, 2000 Additional Information: For additional information on ZOOK rupture disks and products, please visit us by any of the following methods:  On the web at www.zook.cc 543 1043  T Tollll ffree USA att 800 800-543-1043  Local at 440-543-1010  By fax at 440-543-4930 ZOOK Rupture Disk Seminar 7